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Red-neck lathe v2.0
I picked up a few brass candle sticks in garage sales. I wanted to use one
for a brass sundial. It has a long stem and a cup for the candle. The stem is irregular with some patterns on it. I cut the stem off where I thought it would be just about right length for the gnomon. I tried to "turn" it in my old drill press. It turned out not so bad, I put a 10-32 thread on one end and tried to re-profile the rest of it. It is about 5 cm long so I thought I would use the live center I have for my sanding drums. like this one: http://www.leevalley.com/wood/page.a...02&cat=1,42500 This is where I run into a bit of a problem - drilling the centre hole. The candlestick was made in India, I am not sure how. Either way not very well so the whole thing is a bit asymmetrical. I tried to determine the centre of the end to drill a concentric hole but found it almost impossible. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. Now I understand (I hope!) that on a lathe the live centre on the taistock is lined up with the centre of the chuck on the head stock and the hole will be drilled in the centre by default. Not having a lathe the best way I found to drill centres in a round stock is to make a paper tube around it and use a tight fitting transfer punch to mark the centre. This works fine if the stock is cylindrical, not on a candle stick stem which is not. I found a thread on this group from 2004 which provided several options of which the only one viable in my situation would have been to use a 3-jaw chuck to center under the drill press spindle and then substitute the centre drill. And I am indeed looking for a cheap 3-jaw chuck. Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Thanks for all your patience, -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On Wed, 27 Aug 2008 19:16:27 -0700, "Michael Koblic"
wrote: Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Thanks for all your patience, A file works quite well, although slowly. For even slower metal removal, use various forms of scraper (think single tooth file). For coarser work, use hammer and chisel. If you want power assist, use various grinders. Gerry :-)} London, Canada |
Red-neck lathe v2.0
On Aug 27, 10:16 pm, "Michael Koblic" wrote:
This is where I run into a bit of a problem - drilling the centre hole. The candlestick was made in India, I am not sure how. Probably cast. They had sophisticated metalworking skills when my ancestors were still pounding rocks together. AFAIK it was all done in small family shops with simple equipment and never grew into an industry. Holtzapffel book IV, "Hand or Simple Turning" has the best description I've seen of the traditional lathes of the Middle East and Asia and the details of Western lathe development to 1880. You might find the book very useful because the earlier versions were easier to make than a modern lathe. "Simple" is relative; the Holtzapffels were masters of the geometric or rose-engine lathe. The Indian lathe pictured is made of two short stakes driven in the ground with nails through them for centers. The tool rest is a stick tied between them with extra supports as needed. The turner rests his foot on the stick with the tool between his toes for coarse positioning, and guides the end with his hand. A kid pulls the ends of a string wrapped around the work to turn it back and forth. The Arab lathe is only slightly fancier, a box close around the work. He has a bow in one hand to turn the work with the string. The lathe doesn't drive the work, it only supports it between centers. You could turn the work directly with the motor and belt from an old sewing machine, or a rubber caster wheel chucked in a hand drill. Be creative, think of things as what they could do rather than what they were meant for. Your candlesticks may well be copied from a 2000 year old design cast from a wooden pattern made this way. The manual skills of artisans 2000 years ago were easily equal to those today. Perhaps now those people are surgeons rather than craftsmen. As Watt quickly discovered, those artistic skills didn't apply to making precision machinery. Either way not very well so the whole thing is a bit asymmetrical. I tried to determine the centre of the end to drill a concentric hole but found it almost impossible. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. Fix that. A large pointed setscrew held by nuts and washers might work. If you make the head slide down as I suggested you can drill another small hole in the base plate near the large one. You can align them with a piece of wire in the chuck, bicycle spokes work well. Turn it slowly by hand and try to make the circle the point describes small by bending the wire. Move the head until that small circle is centered on your center point. You can check it with a ruler. Now I understand (I hope!) that on a lathe the live centre on the taistock is lined up with the centre of the chuck on the head stock and the hole will be drilled in the centre by default. Not having a lathe the best way I found to drill centres in a round stock is to make a paper tube around it and use a tight fitting transfer punch to mark the centre. This works fine if the stock is cylindrical, not on a candle stick stem which is not. Make a pair of upright Vee supports out of thin material. Rest the candlestick on them at places you consider circular. Turn it while holding a supported pencil against the end. The pencil will mark a small circle around the rotational axis. How well did you learn Euclidean geometry? It has methods for finding the center of a circle or any other shape. One simple way is to guess at the center, put one point of a compass there and see how far off it is when you rotate it. Find where the compass is out furthest and correct half the error by moving the center point, then readjust the other point to the circle and recheck. For me this centers within about 0.010". I found a thread on this group from 2004 which provided several options of which the only one viable in my situation would have been to use a 3-jaw chuck to center under the drill press spindle and then substitute the centre drill. And I am indeed looking for a cheap 3-jaw chuck. Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Brass is a little tricky but it has been turned into exquisite shapes like watch gears with hand-held tools for centuries. Heron of Alexandria's ancient Greek gadget book used (brass?) sheet metal and turned shafts as if they were common hardware items back then. His book described a steam engine and also a vessel with a secret compartment that appears to turn water into wine. If you keep the tool's support close to the stock you avoid those horrible things, otherwise the lathe may practice knife-throwing. I've only done a little free-hand turning of aluminum and can't give you much detailed help. Trying to work metal without machine tools is like going everywhere on foot. When I turn something from oak firewood I draw circles on the ends and rough the blank close to them with a hatchet. On a real metal lathe HSS bits stand up pretty well to interrupted cuts like turning a square steel plate round, just take light cuts. This is one of the jobs that makes a screw-on chuck hard to remove. You can use that drill press center point to drill a centered hole straight through a long piece. Jim Wilkins who -should- be out scraping paint. |
Red-neck lathe v2.0
On Aug 27, 10:16*pm, "Michael Koblic" wrote:
...And I am indeed looking for a cheap 3-jaw chuck.... Michael Koblic, http://www.harborfreight.com/cpi/cta...temnumber=4486 The chuck mount is M12 x 1.0. It isn't too bad for the price. |
Red-neck lathe v2.0
On Wed, 27 Aug 2008 19:16:27 -0700, "Michael Koblic"
wrote: The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? No, there is no trick, just that lathes are usually very heavy and stiff (and have a lot of inertia) compared to the few thou of material that will be removed on each hit.. What you're talking about is called an "interrupted cut" and it causes vibration (and a sound that might be alarming the first time you hear it) but it's not really a problem. You can turn a hex or square piece of stock into round without problems, just don't feed too fast, and, obviously, get the cutter outside for certain before starting or you'll have a "crash" rather than an "interrupted cut"). Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Thanks for all your patience, Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
Red-neck lathe v2.0
"Michael Koblic" wrote in message ... I picked up a few brass candle sticks in garage sales. I wanted to use one for a brass sundial. It has a long stem and a cup for the candle. The stem is irregular with some patterns on it. I cut the stem off where I thought it would be just about right length for the gnomon. I tried to "turn" it in my old drill press. It turned out not so bad, I put a 10-32 thread on one end and tried to re-profile the rest of it. It is about 5 cm long so I thought I would use the live center I have for my sanding drums. like this one: http://www.leevalley.com/wood/page.a...02&cat=1,42500 This is where I run into a bit of a problem - drilling the centre hole. The candlestick was made in India, I am not sure how. Either way not very well so the whole thing is a bit asymmetrical. I tried to determine the centre of the end to drill a concentric hole but found it almost impossible. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. Now I understand (I hope!) that on a lathe the live centre on the taistock is lined up with the centre of the chuck on the head stock and the hole will be drilled in the centre by default. Not having a lathe the best way I found to drill centres in a round stock is to make a paper tube around it and use a tight fitting transfer punch to mark the centre. This works fine if the stock is cylindrical, not on a candle stick stem which is not. I found a thread on this group from 2004 which provided several options of which the only one viable in my situation would have been to use a 3-jaw chuck to center under the drill press spindle and then substitute the centre drill. And I am indeed looking for a cheap 3-jaw chuck. Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Thanks for all your patience, -- Michael Koblic, Campbell River, BC An option to buyalathe is cobble together a facsimilie from surplus. The surplus houses I've been to have mechanical components, or specif purpose machines that have been retired. We've bought lots of little machines for the components. Sometimes you can get a huge pile of stuff for around $100us also, scrounge your local scrap dealer for compnents. For example, a front-wheel-drive auto spindle/bearing assembly is not far removed from a lathe spindle. Early metal turning was done on what were essentially wood lathes, with similar turning tools. Wood lathes are cheep, and/or easy to build. |
Red-neck lathe v2.0
On Aug 27, 8:16*pm, "Michael Koblic" wrote:
I picked up a few brass candle sticks in garage sales. I wanted to use one for a brass sundial. It has a long stem and a cup for the candle. The stem is irregular with some patterns on it. I cut the stem off where I thought it would be just about right length for the gnomon. I tried to "turn" it in my old drill press. It turned out not so bad, I put a *10-32 thread on one end and tried to re-profile the rest of it. It is about 5 cm long so I thought I would use the live center I have for my sanding drums. *like this one: http://www.leevalley.com/wood/page.a...02&cat=1,42500 *This is where I run into a bit of a problem - drilling the centre hole.. The candlestick was made in India, I am not sure how. Either way not very well so the whole thing is a bit asymmetrical. I tried to determine the centre of the end to drill a concentric hole but found it almost impossible. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. Now I understand (I hope!) that on a lathe the live centre on the taistock is lined up with the centre of the chuck on the head stock and the hole will be drilled in the centre by default. Not having a lathe the best way I found to drill centres in a round stock is to make a paper tube around it and use a tight fitting transfer punch to mark the centre. This works fine if the stock is cylindrical, not on a candle stick stem which is not. I found a thread on this group from 2004 which provided several options of which the only one viable in my situation would have been to use a 3-jaw chuck to center under the drill press spindle and then substitute the centre drill. And I am indeed looking for a cheap 3-jaw chuck. Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Thanks for all your patience, -- Michael Koblic, Campbell River, BC Marking rough castings for centerdrilling used to be a must-have skill. My 1905 Audel's shows one way. You use an oddleg caliper, one leg is curved like normal outside calipers, the other is straight(and sharp). Set the thing a little more than half-way to the other side and draw an arc off the edge. Rotate about 90 degrees and repeat, repeat 2 more times and and you'll have a rough box shape marked out. Use a machinist's rule across the diagonal and scribe a line. Repeat. Centerpunch the intersection and it should be close enough to center. Drill using a center drill. Repeat on the other end. As far as interrupted cuts, castings were snagged off using chisels and grinders so they weren't really too far out. With iron castings, you have to make sure you get under the hard skin on the first cut, otherwise the tool edge disappears. With brass, you just have to make sure you aren't cutting sponge with embedded sand. Slow speeds and feeds help if the lathe isn't a 2 ton heavyweight. Once the interrupted cut disappears, speed can be increased. Stan |
Red-neck lathe v2.0
"Gerald Miller" wrote in message ... A file works quite well, although slowly. For even slower metal removal, use various forms of scraper (think single tooth file). For coarser work, use hammer and chisel. If you want power assist, use various grinders. For this job symmetry was the main requirement. I find it very hard to file irregular-shaped bars to make them into cylinders. I tried the "reverse lathe" method using a bench sander. However, the part is quite small and fingers are definitely an issue. I tried chucking it but the set up was suboptimal and I nearly killed the part outright. Stopped just in time. I just took apart a very old Sears cordless drill and will try again tomorrow with a better chucking arrangement. |
Red-neck lathe v2.0
"Jim Wilkins" wrote in message ... The candlestick was made in India, I am not sure how. Probably cast. On close inspection I suspect you are right. The lathe doesn't drive the work, it only supports it between centers. You could turn the work directly with the motor and belt from an old sewing machine, or a rubber caster wheel chucked in a hand drill. Be creative, think of things as what they could do rather than what they were meant for. I do. Some "thoughts" would make your hair stand on end...:-) I tried to determine the centre of the end to drill a concentric hole but found it almost impossible. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. Fix that. A large pointed setscrew held by nuts and washers might work. If you make the head slide down as I suggested you can drill another small hole in the base plate near the large one. You can align them with a piece of wire in the chuck, bicycle spokes work well. Turn it slowly by hand and try to make the circle the point describes small by bending the wire. Move the head until that small circle is centered on your center point. You can check it with a ruler. I have re-read this about six times and I am not altogether sure that I understood: I have no difficulty aligning the centre point of the live centre with the centre of the spindle. However, when I chuck the gnomon and put the opposite end on the live centre (using the supposedly centre hole I drilled), the gnomon, being slightly out of alignment, moves the live centre around. Now I understand (I hope!) that on a lathe the live centre on the taistock is lined up with the centre of the chuck on the head stock and the hole will be drilled in the centre by default. Not having a lathe the best way I found to drill centres in a round stock is to make a paper tube around it and use a tight fitting transfer punch to mark the centre. This works fine if the stock is cylindrical, not on a candle stick stem which is not. Make a pair of upright Vee supports out of thin material. Rest the candlestick on them at places you consider circular. Turn it while holding a supported pencil against the end. The pencil will mark a small circle around the rotational axis. How well did you learn Euclidean geometry? It has methods for finding the center of a circle or any other shape. One simple way is to guess at the center, put one point of a compass there and see how far off it is when you rotate it. Find where the compass is out furthest and correct half the error by moving the center point, then readjust the other point to the circle and recheck. For me this centers within about 0.010". The euclid works if the cross-section is truly circular. In the case of this piece it is not. Furthermore, the smaller the diameter (in ,my case about 1/4") the more difficult the method, even if the cross-section is truly circular. I have used this: http://www.leevalley.com/wood/page.a...65&cat=1,42936 (the centre-finding head) but the transfer punch/paper roll method beats it every time particularly for small parts. There is this: http://www.victornet.com/cgi-bin/vic...uares% 3A1242 but I have never used it and wonder if it improves accuracy over the other one. The other issue with very small parts is to actually hit the right spot with a centre punch: I have been using a lamp with a magnifying lens and even that is not particularly great. I am thinking of getting this: http://www.leevalley.com/wood/page.a...=1,42936,50298 Maybe with a centre drill you do not need to punch? Am I right in that? I found a thread on this group from 2004 which provided several options of which the only one viable in my situation would have been to use a 3-jaw chuck to center under the drill press spindle and then substitute the centre drill. And I am indeed looking for a cheap 3-jaw chuck. Are there any other suggestions ("Buy a lathe!" does not count)? The other thing that puzzles me (and please note that the nearest I have been to a lathe is in the movies and picutres in books) is how do you start turning something that is irregular in shape? Or even how do you turn a round piece out of a square stock? Does it not do horrible things to the cutting tool when it contacts only at the corners? Or is there a trick to get the shape roughly round first somehow? I want to change the shape of the brass cup but the initial attempt was somewhat discouraging. Brass is a little tricky but it has been turned into exquisite shapes like watch gears with hand-held tools for centuries. Heron of Alexandria's ancient Greek gadget book used (brass?) sheet metal and turned shafts as if they were common hardware items back then. His book described a steam engine and also a vessel with a secret compartment that appears to turn water into wine. If you keep the tool's support close to the stock you avoid those horrible things, otherwise the lathe may practice knife-throwing. I've only done a little free-hand turning of aluminum and can't give you much detailed help. Trying to work metal without machine tools is like going everywhere on foot. I was basically using files supported by a wooden block as close as possible to the piece. I am not brave enough yet to try a proper cutting tool. I gotta get more space on Flickr - it is so much easier to show pictures. Anyway, thanks for the advice. -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
"Jim Wilkins" wrote in message ... On Aug 27, 10:16 pm, "Michael Koblic" wrote: ...And I am indeed looking for a cheap 3-jaw chuck.... Michael Koblic, http://www.harborfreight.com/cpi/cta...temnumber=4486 The chuck mount is M12 x 1.0. It isn't too bad for the price. ****Thanks, but AFAIK they do not ship to Canada. I have a few under surveillance on EBay. |
Red-neck lathe v2.0
"Jon" wrote in message news:u4ztk.949$p72.578@trnddc05... An option to buyalathe is cobble together a facsimilie from surplus. The surplus houses I've been to have mechanical components, or specif purpose machines that have been retired. We've bought lots of little machines for the components. Sometimes you can get a huge pile of stuff for around $100us also, scrounge your local scrap dealer for compnents. For example, a front-wheel-drive auto spindle/bearing assembly is not far removed from a lathe spindle. Early metal turning was done on what were essentially wood lathes, with similar turning tools. Wood lathes are cheep, and/or easy to build. I am slowly acquiring a pile of stuff. Right now the closest I am getting is the old drill press. I am wondering if simply mounting it on its side and improvising some sort of tailstock in the place of the base might be a good idea... |
Red-neck lathe v2.0
wrote in message ... Marking rough castings for centerdrilling used to be a must-have skill. My 1905 Audel's shows one way. You use an oddleg caliper, one leg is curved like normal outside calipers, the other is straight(and sharp). Set the thing a little more than half-way to the other side and draw an arc off the edge. Rotate about 90 degrees and repeat, repeat 2 more times and and you'll have a rough box shape marked out. Use a machinist's rule across the diagonal and scribe a line. Repeat. Centerpunch the intersection and it should be close enough to center. Drill using a center drill. Repeat on the other end. ***I believe it is called a hermaphrodite caliper. I have one of those but on small parts it is quite useless. I have gone into this in my reply to Jim Wilkins. I did like his idea of spinning the part and letting a pencil draw a circle about the rotational axis the other end. I have not tried it yet. As far as interrupted cuts, castings were snagged off using chisels and grinders so they weren't really too far out. With iron castings, you have to make sure you get under the hard skin on the first cut, otherwise the tool edge disappears. With brass, you just have to make sure you aren't cutting sponge with embedded sand. ***That would be the residue of casting? Thanks -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On Aug 28, 11:51 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message Some "thoughts" would make your hair stand on end...:-) What little hair is left... :-( (that's a beard, I grow it wherever I still can) I've run the model shop in electronics companies and thus dealt with the creative misadventures of clever engineers with no practical experience. In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. A large pointed setscrew held by nuts and washers might work. Setscrew pointed upward for the center, nuts and washers to hold it tight in the hole. ...You can align them with a piece of wire in the chuck,... I have re-read this about six times and I am not altogether sure that I understood: I have no difficulty aligning the centre point of the live centre with the centre of the spindle. However, when I chuck the gnomon and put the opposite end on the live centre (using the supposedly centre hole I drilled), the gnomon, being slightly out of alignment, moves the live centre around. http://www.lindsaybks.com/bks/advmach/index.html Don't be put off by its age. Production techniques may have improved dramatically since then but manual lathe operations are still the same. If the chuck doesn't hold the part straight you mount it between centers and drive it with a dog. I think a 4-sided pyramidal point held in the drill chuck is enough to drive brass without a dog if you take light cuts. You don't need to make the point run perfectly true as long as you mark it so you can remove and replace the work. How well did you learn Euclidean geometry? The euclid works if the cross-section is truly circular. There are constructions for centering even a triangle. A quick shortcut I often use is to center a thin 6" flex rule across the work by equalizing the end readings. For example one end is at 1-1/8", the other at 4-7/8". Hold a scriber point against the work at the 3" mark, then turn the rule 90 degrees and repeat. I like the style of graduations called 3R for this. but the transfer punch/paper roll method beats it every time particularly for small parts. That's a good idea I hadn't seen before. Then again I have a collet lathe which is the perfect machine for making small round parts. Mine would be a little more perfect if it hadn't been abused in trade school. A small lathe with a 3-jaw chuck is close. http://www.mini-lathe.com/ Maybe with a centre drill you do not need to punch? Am I right in that? See the center/spot/stub drill thread. With less rigid equipment like your drill press and my 50-year-old milling machine you have to learn what works and what doesn't. The punch mark is to align the drill bit with your hand layout since it's very difficult to position the center of the drill bit directly. Jim Wilkins |
Red-neck lathe v2.0
"Jim Wilkins" wrote in message ... On Aug 28, 11:51 pm, "Michael Koblic" wrote: "Jim Wilkins" wrote in message Some "thoughts" would make your hair stand on end...:-) What little hair is left... :-( (that's a beard, I grow it wherever I still can) I've run the model shop in electronics companies and thus dealt with the creative misadventures of clever engineers with no practical experience. Judging from your e-mail address you will understand how electronics were done by amateurs before the advent of the black boxes. Except we did not have black boxes: we had Wehrmacht surplus. And ingenuity. And fire insurance... In the end when hooked up to the live centre (which is loose on the drill press table) the live centre was running around in a small circle whatever I did. A large pointed setscrew held by nuts and washers might work. Setscrew pointed upward for the center, nuts and washers to hold it tight in the hole. I see. I could actually clamp the "live center" in a drill press vise and position it. I was just thinking what kind of rotation will happen to the piece if its so bent that it moves the centre around when *not* clamped. I guess it will find a way... ...You can align them with a piece of wire in the chuck,... I have re-read this about six times and I am not altogether sure that I understood: I have no difficulty aligning the centre point of the live centre with the centre of the spindle. However, when I chuck the gnomon and put the opposite end on the live centre (using the supposedly centre hole I drilled), the gnomon, being slightly out of alignment, moves the live centre around. http://www.lindsaybks.com/bks/advmach/index.html Don't be put off by its age. Production techniques may have improved dramatically since then but manual lathe operations are still the same. For that I thank you. In fact I have been actively looking for older texts which are more in keeping with what I am doing. I think I mentioned the old blacksmith book with wooden bearings etc. He goes into lathes a bit but not in enough detail (where, as far as I am concerned, is where the God is). I am waiting for my first order from Smartflix so I can see these things actually happening. They have some extensive courses on milling and lathing. If it works out renting from them I should move forward more quickly. In any case, I have ordered the book you recommended. If the chuck doesn't hold the part straight you mount it between centers and drive it with a dog. I think a 4-sided pyramidal point held in the drill chuck is enough to drive brass without a dog if you take light cuts. You don't need to make the point run perfectly true as long as you mark it so you can remove and replace the work. Does the dog not object? Juvenile humour aside, now I have to study how to use a dog! I thought a dog was a sort of bent thing which held parts to a face plate if you did not have a chuck... How well did you learn Euclidean geometry? The euclid works if the cross-section is truly circular. There are constructions for centering even a triangle. A quick shortcut I often use is to center a thin 6" flex rule across the work by equalizing the end readings. For example one end is at 1-1/8", the other at 4-7/8". Hold a scriber point against the work at the 3" mark, then turn the rule 90 degrees and repeat. I like the style of graduations called 3R for this. 3" yes. 0.3" no... but the transfer punch/paper roll method beats it every time particularly for small parts. That's a good idea I hadn't seen before. Then again I have a collet lathe which is the perfect machine for making small round parts. Mine would be a little more perfect if it hadn't been abused in trade school. A small lathe with a 3-jaw chuck is close. http://www.mini-lathe.com/ Ha! You heard it here first! I have never seen it myself elsewhere, it just came to me when I was trying to drill centre hole in the end of a 3/16" copper rivet to stick on the end of my gnomon. I had to make another jig to hold the rivet in the drill press vise but it works just fine. Maybe with a centre drill you do not need to punch? Am I right in that? See the center/spot/stub drill thread. With less rigid equipment like your drill press and my 50-year-old milling machine you have to learn what works and what doesn't. The punch mark is to align the drill bit with your hand layout since it's very difficult to position the center of the drill bit directly. I have been following that thread - and I was not sure. I bought a centre drill and promptly broke one end. The other end worked well, but I used a punch. I believe you have to run them quite fast. As an update: I bought a $17 Jacobs 1/2" chuck today and was able to chuck one of the brass cups in it safely and tidied it up by the "reverse lathe" method of holding it and rotating it by hand against a 220-grit belt sander. I even found 3 1/2"-20 bolts of different lengths and am thinking of making a jig to drill concentric holes along the lines recommended in the 2004 thread (there they used a wooden block on its side to drill a centre hole in a long rod - rather ingenious I thought). -- Michael Koblic, Campbell River, BC -ex OL1AGS -ex G4GIU -ex GW4GIU -VE7EQG (QRT 7 years) |
Red-neck lathe v2.0
On 2008-08-30, Michael Koblic wrote:
"Jim Wilkins" wrote in message ... On Aug 28, 11:51 pm, "Michael Koblic" wrote: "Jim Wilkins" wrote in message [ ... ] A large pointed setscrew held by nuts and washers might work. Setscrew pointed upward for the center, nuts and washers to hold it tight in the hole. I see. I could actually clamp the "live center" in a drill press vise and position it. If you add a V block to the vise to keep things from shifting. upright round objects are difficult to clamp reliably in a vise, but add a V-block and you can do a better job with a cylindrical item. However a live center typicaly has a Morse taper shank, so you'll need some extra tricks to make up for the taper itself. I was just thinking what kind of rotation will happen to the piece if its so bent that it moves the centre around when *not* clamped. I guess it will find a way... :-) [ ... ] http://www.lindsaybks.com/bks/advmach/index.html Don't be put off by its age. Production techniques may have improved dramatically since then but manual lathe operations are still the same. For that I thank you. In fact I have been actively looking for older texts which are more in keeping with what I am doing. I think I mentioned the old blacksmith book with wooden bearings etc. He goes into lathes a bit but not in enough detail (where, as far as I am concerned, is where the God is). I am waiting for my first order from Smartflix so I can see these things actually happening. They have some extensive courses on milling and lathing. Hopefully, they will also tell you that while you are using a lahte, you are *not* "lathing", but rather "turning". :-) If it works out renting from them I should move forward more quickly. In any case, I have ordered the book you recommended. If the chuck doesn't hold the part straight you mount it between centers and drive it with a dog. I think a 4-sided pyramidal point held in the drill chuck is enough to drive brass without a dog if you take light cuts. You don't need to make the point run perfectly true as long as you mark it so you can remove and replace the work. Does the dog not object? Juvenile humour aside, now I have to study how to use a dog! I thought a dog was a sort of bent thing which held parts to a face plate if you did not have a chuck... It is used with a face plate, to impart rotation to a workpiece suspended between centers. The one in the headstock spindle rotates, but it does not have enough contact area to really drive the workpiece, so the dog is clamped onto a part of the workpiece which you are not (currently) changing, and its tail is driven by a slot in the faceplate (if a bent-tail dog), or by a bolt through the faceplate (if a straight tail dog). These do not wag. :-) If you are trying to drive something with a drill chuck which has a poor enough finish on the end so you can't clamp it and prevent it from wobbling, then you clamp the drill chuck onto some steel rod, take a file to it while it is rotating to form it to a point (60 degree angle), and use this to hold the upper end of your workpiece. You will then need to clamp a bent-tail dog onto the upper end of the workpiece, and a collar of some sort around the drill chuck to drive the dog's tail. Another thing to worry about is that most drill presses don't go slow enough, and if the workpiece, collar, and dog are not fairly well balanced, the drill press will try to walk around the floor (or the workbench, if it is a benchtop drill press). [ ... ] That's a good idea I hadn't seen before. Then again I have a collet lathe which is the perfect machine for making small round parts. Mine would be a little more perfect if it hadn't been abused in trade school. A small lathe with a 3-jaw chuck is close. http://www.mini-lathe.com/ Ha! You heard it here first! I have never seen it myself elsewhere, it just came to me when I was trying to drill centre hole in the end of a 3/16" copper rivet to stick on the end of my gnomon. I had to make another jig to hold the rivet in the drill press vise but it works just fine. The ability to make fixtures is an important one in any kind of metalwork, and some woodwork as well. Maybe with a centre drill you do not need to punch? Am I right in that? See the center/spot/stub drill thread. With less rigid equipment like your drill press and my 50-year-old milling machine you have to learn what works and what doesn't. The punch mark is to align the drill bit with your hand layout since it's very difficult to position the center of the drill bit directly. I have been following that thread - and I was not sure. I bought a centre drill and promptly broke one end. The other end worked well, but I used a punch. I believe you have to run them quite fast. How large a diameter of center drill? The proper speed for one is a function of its maximum diameter -- and the metal into which you are drilling. To avoid snapping off the point, you need a way to prevent the workpiece from tilting in the drill press. Also, a proper coolant/cutting fluid would help them to survive. But center drills (like all drills) are "consumables" so keep spares on hand. Good Luck, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Red-neck lathe v2.0
"DoN. Nichols" wrote in message ... If you add a V block to the vise to keep things from shifting. upright round objects are difficult to clamp reliably in a vise, but add a V-block and you can do a better job with a cylindrical item. However a live center typicaly has a Morse taper shank, so you'll need some extra tricks to make up for the taper itself. My vise has a sort of vertical v-block incorporated. My "live centre" really only remotely resembles a proper lathe live centre. I was just thinking what kind of rotation will happen to the piece if its so bent that it moves the centre around when *not* clamped. I guess it will find a way... It is used with a face plate, to impart rotation to a workpiece suspended between centers. The one in the headstock spindle rotates, but it does not have enough contact area to really drive the workpiece, so the dog is clamped onto a part of the workpiece which you are not (currently) changing, and its tail is driven by a slot in the faceplate (if a bent-tail dog), or by a bolt through the faceplate (if a straight tail dog). These do not wag. :-) For that you need a wiggler? If you are trying to drive something with a drill chuck which has a poor enough finish on the end so you can't clamp it and prevent it from wobbling, then you clamp the drill chuck onto some steel rod, take a file to it while it is rotating to form it to a point (60 degree angle), and use this to hold the upper end of your workpiece. You will then need to clamp a bent-tail dog onto the upper end of the workpiece, and a collar of some sort around the drill chuck to drive the dog's tail. OK, now I found some nice pictures and I understand it. Sort of. Another thing to worry about is that most drill presses don't go slow enough, and if the workpiece, collar, and dog are not fairly well balanced, the drill press will try to walk around the floor (or the workbench, if it is a benchtop drill press). At this point using the canine arrangement on my drill press fills me with a sense of dread. Also, the parts I am turning are very small, so a really small dog would be required. A chihuahua... How large a diameter of center drill? The proper speed for one is a function of its maximum diameter -- and the metal into which you are drilling. 1/8" To avoid snapping off the point, you need a way to prevent the workpiece from tilting in the drill press. Also, a proper coolant/cutting fluid would help them to survive. But center drills (like all drills) are "consumables" so keep spares on hand. I swear the first one snapped just by me looking at it... I just took apart a very old Sears cordless drill and liberated a 12V motor as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found an old 12V motor with some strange reduction gear which, many years ago was going to be a pottery wheel for kids. Some of this stuff has got to be useful even though 12V is not exactly ideal. If it was straightforward it would not be fun... -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On Aug 29, 10:06 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message On Aug 28, 11:51 pm, "Michael Koblic" wrote: "Jim Wilkins" wrote in message Judging from your e-mail address you will understand how electronics were done by amateurs before the advent of the black boxes. Except we did not have black boxes: we had Wehrmacht surplus. And ingenuity. And fire insurance... We had plenty of US mil-surp gear to play with too. The aircraft stuff often ran on 400 Hz AC and operated on 225-400 MHz which is military- only here. I used to have a working copy of a German aircraft-detection radar transmitter from 1931(?) sitting on my Mac's monitor. It consisted of a high-voltage transformer and a spark gap. The two spark gap electrodes formed a dipole about 100mm long. There was enough lead wire connected to it that I wouldn't predict the frequency and I expect it was broadly tuned, but it could have been over 1 GHz. When I rescued it from a lab I was closing down it was in an aquarium tank because it was so dangerous. I removed the power cord. Spark gap transmitters are illegal to operate now anyway. As I understand it, the receiver was shielded from the transmitter and only received the CW signal when it reflected off an airplane. Detecting the audio-frequency Doppler shift in the return seems unlikely for biplane speeds and spark-gap bandwidth and it goes away as the plane approaches. In "The Wizard War" Dr Jones wrote that early '40's German field radar transmitters were as stable in frequency as the best British lab standards, apparently because they could grind quartz crystals better. He certainly had a lot of respect for German equipment. Then again, the British chose to use American aircraft radios rather than their own. As with Russia and Japan their theoretical and lab work was excellent but they had trouble mass producing it. but the transfer punch/paper roll method beats it every time particularly for small parts. That's a good idea I hadn't seen before. Ha! You heard it here first! The traditional center punching tool looks like a funnel with the center punch sliding in the spout. These are a gold mine of information; http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/ 0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3 If the link is broken, Google for "Holtzapffel" The yellow one concentrates on turning and should answer your questions very well, the red one is about hand tools and the history of screw threads. I don't have the other books yet. They describe Victorian-era technology in exquisite detail from a master toolmaker's perspective and often give the inventor of our common tools, for example Mr. Hale registered the centering square in 1862, Holtzapffel and Deyerlein began making 3-jaw self-centering lathe chucks in 1811. Like anything German they are ignored in most English-language history books although they worked in London since 1787 and helped train Whitworth. "English and American Tool Builders" gives them only a paragraph. The Holtzappfel books complement that biographical one by showing their work. Jim Wilkins |
Red-neck lathe v2.0
On Aug 30, 10:48*am, Jim Wilkins wrote:
.... http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/ 0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3 It worked when I copied both halves into the address bar separately. |
Red-neck lathe v2.0
On Sat, 30 Aug 2008 08:45:45 -0700, Jim Wilkins wrote:
On Aug 30, 10:48Â*am, Jim Wilkins wrote: ... http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/ 0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3 It worked when I copied both halves into the address bar separately. I guess you are talking about how to deal with a URL that is split across lines. The way I usually deal with URL's like that is to ignore them and go on to the next post. But if I actually want to see them I could highlight all of the URL and paste it into firefox's address bar, then delete extraneous characters. For example, if I highlighted from "http:" through "=1-3" in the above and pasted it, the address bar would look like it started off with " 048" (ie the newline disappeared the first part) and I then could put the cursor on the blank, press backspace 4 times, and Enter to see the web page. That's what I could do; what I actually do in such a case is highlight all of the URL, then click a button for a script that strips out newlines from selection and sends it off to firefox to display. (In a case like the above I'd still have to delete some extraneous characters in the address bar.) -jiw |
Red-neck lathe v2.0
On 2008-08-30, Michael Koblic wrote:
"DoN. Nichols" wrote in message ... If you add a V block to the vise to keep things from shifting. upright round objects are difficult to clamp reliably in a vise, but add a V-block and you can do a better job with a cylindrical item. However a live center typically has a Morse taper shank, so you'll need some extra tricks to make up for the taper itself. My vise has a sort of vertical v-block incorporated. My "live centre" really only remotely resembles a proper lathe live centre. O.K. The v-groove in the vise (likely not a very deep one, but something to help) is a start. Ideal depth of V-groove would be such that the two sides of the 'V' are tangent to the diameter of the thing being held. If it is shallow enough so the tops of the V touch the circumference of the workpiece it will cut grooves into the workpiece and will not be as good a grip. Of course, some vises (e.g. toolmakers vises) have deeper grooves than others do. As for your "live center" -- is it at least a pointed part held in bearings so it is free to rotate? That is a start. If it is not free to rotate, then it is just a center, not a *live* center. Of course -- way back before bearing mounted centers in the tailstock became common, the center in the headstock was called "live" (because it rotated), and the one in the tailstock was called "dead" because it did not. And the point of contact between the tailstock center and the workpiece was lubricated with "white lead" (a lead oxide, IIRC) -- something considered a hazardous material these days. :-) There was typically a small well in the tailstock casting, and a plug which would dip out some and could apply it to the center/hole interface. I was just thinking what kind of rotation will happen to the piece if its so bent that it moves the centre around when *not* clamped. I guess it will find a way... It is used with a face plate, to impart rotation to a workpiece suspended between centers. The one in the headstock spindle rotates, but it does not have enough contact area to really drive the workpiece, so the dog is clamped onto a part of the workpiece which you are not (currently) changing, and its tail is driven by a slot in the faceplate (if a bent-tail dog), or by a bolt through the faceplate (if a straight tail dog). These do not wag. :-) For that you need a wiggler? Well ... actually a "wiggler" is an indicator used for moving centers of the workpiece over/under the axis of the lathe, mill, or drill press spindles. If you are trying to drive something with a drill chuck which has a poor enough finish on the end so you can't clamp it and prevent it from wobbling, then you clamp the drill chuck onto some steel rod, take a file to it while it is rotating to form it to a point (60 degree angle), and use this to hold the upper end of your workpiece. You will then need to clamp a bent-tail dog onto the upper end of the workpiece, and a collar of some sort around the drill chuck to drive the dog's tail. OK, now I found some nice pictures and I understand it. Sort of. Good -- pictures do help a lot. You know -- there are downloadable PDF files of various old books (out of copyright) which are very good things to have for what you are trying to do -- or for anyone with an old manual lathe, mill, and other such tools. Another thing to worry about is that most drill presses don't go slow enough, and if the workpiece, collar, and dog are not fairly well balanced, the drill press will try to walk around the floor (or the workbench, if it is a benchtop drill press). At this point using the canine arrangement on my drill press fills me with a sense of dread. Also, the parts I am turning are very small, so a really small dog would be required. A chihuahua... I've got one of those -- a dog which came with my Unimat SL-1000 back around 1970 or so. Hmm ... a pity that Unimat of that vintage are now being treated as collectors items on eBay. Otherwise, it could be a reasonable lathe for making your gnomen, albeit a bit small for turning the scale ring (whatever it is called). Yes. If you had a lathe, you could make a disc shaped dog, with a disc to hold the "tail" and a setscrew from the other end, and you could add bolts to the side opposite the dog to balance the tail. You could also make something which would clamp on the bottom section of the chuck (after it was tightened) which had two or three evenly spaced slots to engage the dog tail -- and not need to worry about its balance. This would leave only the workpiece itself, and if it is as small as you say, it probably would not have any significant problems with balance. *But* -- if you had a lathe, you would not need to do all of this anyway. :-) How large a diameter of center drill? The proper speed for one is a function of its maximum diameter -- and the metal into which you are drilling. 1/8" O.K. Yes, that would want to run fairly fast. 2000 RPM would be only slightly over 65 SFM (Surface Feet per Minute -- the measure used for determining the speed of the workpiece/tool interface. (take the diameter in inches, multiply by Pi, divide by 12 to give the circumference in feet, and divide that into the RPM. That is a fairly conservative speed for HSS (High Speed Steel) in brass. To avoid snapping off the point, you need a way to prevent the workpiece from tilting in the drill press. Also, a proper coolant/cutting fluid would help them to survive. But center drills (like all drills) are "consumables" so keep spares on hand. I swear the first one snapped just by me looking at it... It feels like that sometimes. Were you using it in a drill press, or in a hand drill? The drill press is the better bet. And don't just keep pushing it in -- go a little way in, then back the spindle up to let chips clear, then in again, etc. Normally you don't need cutting fluids on a free-machining brass, but I don't know what the characteristics of the cast brass which you are working with might be. I wonder whether it could be a bronze? Not likely, as those are more expensive, but they are tougher alloys. I just took apart a very old Sears cordless drill and liberated a 12V motor as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found an old 12V motor with some strange reduction gear which, many years ago was going to be a pottery wheel for kids. Some of this stuff has got to be useful even though 12V is not exactly ideal. An old automobile battery and a battery charger to keep it near full charge and you should be fine. And that would be a lot cheaper than a lab power supply of sufficient capacity to handle your tools. (Hmm ... if it is small enough, perhaps a motorcycle battery would be sufficient. If it was straightforward it would not be fun... :-) Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Red-neck lathe v2.0
----- Original Message ----- From: "DoN. Nichols" Newsgroups: rec.crafts.metalworking Sent: Saturday, August 30, 2008 1:47 PM Subject: Red-neck lathe v2.0 O.K. The v-groove in the vise (likely not a very deep one, but something to help) is a start. Ideal depth of V-groove would be such that the two sides of the 'V' are tangent to the diameter of the thing being held. If it is shallow enough so the tops of the V touch the circumference of the workpiece it will cut grooves into the workpiece and will not be as good a grip. Of course, some vises (e.g. toolmakers vises) have deeper grooves than others do. So far so good, but I have also a couple of bigger v-blocks if need be. As for your "live center" -- is it at least a pointed part held in bearings so it is free to rotate? That is a start. If it is not free to rotate, then it is just a center, not a *live* center. It does that. For that you need a wiggler? Well ... actually a "wiggler" is an indicator used for moving centers of the workpiece over/under the axis of the lathe, mill, or drill press spindles. That was supposed to be a joke... Good -- pictures do help a lot. You know -- there are downloadable PDF files of various old books (out of copyright) which are very good things to have for what you are trying to do -- or for anyone with an old manual lathe, mill, and other such tools. I am beginning to find them. It seems tricky. You do the search one way and nothing happens, you do it another and out they pop.. *But* -- if you had a lathe, you would not need to do all of this anyway. :-) And there is the nub of the matter... O.K. Yes, that would want to run fairly fast. 2000 RPM would be only slightly over 65 SFM (Surface Feet per Minute -- the measure used for determining the speed of the workpiece/tool interface. (take the diameter in inches, multiply by Pi, divide by 12 to give the circumference in feet, and divide that into the RPM. That is a fairly conservative speed for HSS (High Speed Steel) in brass. I run most of my drills slower than the book speed. I have not find a convincing argument that it is harmful to the tools. The centre drills seem to be an exception - they snap at lower speeds. I swear the first one snapped just by me looking at it... It feels like that sometimes. Were you using it in a drill press, or in a hand drill? The drill press is the better bet. And don't just keep pushing it in -- go a little way in, then back the spindle up to let chips clear, then in again, etc. Normally you don't need cutting fluids on a free-machining brass, but I don't know what the characteristics of the cast brass which you are working with might be. I wonder whether it could be a bronze? Not likely, as those are more expensive, but they are tougher alloys. Garage sale candlesticks - generic brass all the way. Very soft. I just took apart a very old Sears cordless drill and liberated a 12V motor as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found an old 12V motor with some strange reduction gear which, many years ago was going to be a pottery wheel for kids. Some of this stuff has got to be useful even though 12V is not exactly ideal. An old automobile battery and a battery charger to keep it near full charge and you should be fine. And that would be a lot cheaper than a lab power supply of sufficient capacity to handle your tools. (Hmm ... if it is small enough, perhaps a motorcycle battery would be sufficient. I have a couple of power supplies - one should give steady 5 amps which as it turns out may not be enough. The other one should give 20 amps. I have not tried that one yet. Note to self: Do not take motors apart without securing the brushes first! A good way to avoid doing anything productive for an hour... Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
"Jim Wilkins" wrote in message ... .... We had plenty of US mil-surp gear to play with too. The aircraft stuff often ran on 400 Hz AC and operated on 225-400 MHz which is military- only here. I used to have a working copy of a German aircraft-detection radar transmitter from 1931(?) sitting on my Mac's monitor. It consisted of a high-voltage transformer and a spark gap. The two spark gap electrodes formed a dipole about 100mm long. There was enough lead wire connected to it that I wouldn't predict the frequency and I expect it was broadly tuned, but it could have been over 1 GHz. When I rescued it from a lab I was closing down it was in an aquarium tank because it was so dangerous. I removed the power cord. Spark gap transmitters are illegal to operate now anyway. As I understand it, the receiver was shielded from the transmitter and only received the CW signal when it reflected off an airplane. Detecting the audio-frequency Doppler shift in the return seems unlikely for biplane speeds and spark-gap bandwidth and it goes away as the plane approaches. In "The Wizard War" Dr Jones wrote that early '40's German field radar transmitters were as stable in frequency as the best British lab standards, apparently because they could grind quartz crystals better. He certainly had a lot of respect for German equipment. Then again, the British chose to use American aircraft radios rather than their own. As with Russia and Japan their theoretical and lab work was excellent but they had trouble mass producing it. Those were the good days... but the transfer punch/paper roll method beats it every time particularly for small parts. That's a good idea I hadn't seen before. Ha! You heard it here first! The traditional center punching tool looks like a funnel with the center punch sliding in the spout. Funny, I thought I could not have been *that* original. I went looking for something like that on the net but could not find it. These are a gold mine of information; http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/ 0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3 If the link is broken, Google for "Holtzapffel" Nah, someone else sends me links this way. I just link the first half and paste in the second line. Got it just fine, thanks. The yellow one concentrates on turning and should answer your questions very well, the red one is about hand tools and the history of screw threads. I don't have the other books yet. They describe Victorian-era technology in exquisite detail from a master toolmaker's perspective and often give the inventor of our common tools, for example Mr. Hale registered the centering square in 1862, Holtzapffel and Deyerlein began making 3-jaw self-centering lathe chucks in 1811. Like anything German they are ignored in most English-language history books although they worked in London since 1787 and helped train Whitworth. "English and American Tool Builders" gives them only a paragraph. The Holtzappfel books complement that biographical one by showing their work. Solch' is das Leben... -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On 2008-08-31, Michael Koblic wrote:
----- Original Message ----- From: "DoN. Nichols" Newsgroups: rec.crafts.metalworking Sent: Saturday, August 30, 2008 1:47 PM Subject: Red-neck lathe v2.0 O.K. The v-groove in the vise (likely not a very deep one, but something to help) is a start. Ideal depth of V-groove would be such that the two sides of the 'V' are tangent to the diameter of the thing being held. If it is shallow enough so the tops of the V touch the circumference of the workpiece it will cut grooves into the workpiece and will not be as good a grip. Of course, some vises (e.g. toolmakers vises) have deeper grooves than others do. So far so good, but I have also a couple of bigger v-blocks if need be. Good. [ ... ] For that you need a wiggler? Well ... actually a "wiggler" is an indicator used for moving centers of the workpiece over/under the axis of the lathe, mill, or drill press spindles. That was supposed to be a joke... O.K. No smiley, so I wasn't sure. Good -- pictures do help a lot. You know -- there are downloadable PDF files of various old books (out of copyright) which are very good things to have for what you are trying to do -- or for anyone with an old manual lathe, mill, and other such tools. I am beginning to find them. It seems tricky. You do the search one way and nothing happens, you do it another and out they pop.. Try to find "Modern Machine Shop Practice" (I forget whether that last word should have an 's' on the end. :-) Don't confuse it with "Machine Shop Practice" by Moultrecht which is a two-volume set. It is a good book set to have, but you won't find it for free. [ ... ] O.K. Yes, that would want to run fairly fast. 2000 RPM would be only slightly over 65 SFM (Surface Feet per Minute -- the measure used for determining the speed of the workpiece/tool interface. (take the diameter in inches, multiply by Pi, divide by 12 to give the circumference in feet, and divide that into the RPM. That is a fairly conservative speed for HSS (High Speed Steel) in brass. I run most of my drills slower than the book speed. I have not find a convincing argument that it is harmful to the tools. It typically puts more stress on the flutes of bits. The centre drills seem to be an exception - they snap at lower speeds. Hmm ... check your drill press. Put a round tip piece of stock in the drill chuck, put a flat piece of metal on the table, and bring the round end of the rod down on the piece of metal. Look carefully at the point of contact as you apply pressure. A lot of relatively inexpensive drill presses flex -- both the arm supporting the table and the head. This results in the contact point skidding towards you. This applies lateral force to the point -- and with the skinny point of a 1/8" center drill and it *will* break. A higher speed means that you are less likely to apply as much force to the spindle feed levers. I swear the first one snapped just by me looking at it... It feels like that sometimes. Were you using it in a drill press, or in a hand drill? The drill press is the better bet. And don't just keep pushing it in -- go a little way in, then back the spindle up to let chips clear, then in again, etc. Normally you don't need cutting fluids on a free-machining brass, but I don't know what the characteristics of the cast brass which you are working with might be. I wonder whether it could be a bronze? Not likely, as those are more expensive, but they are tougher alloys. Garage sale candlesticks - generic brass all the way. Very soft. Very soft can be a problem -- it gums up the flutes of the bit. 360L brass has lead in it and is a bit harder than normal brass, but the lead lubricates the cuts, so it is a very nice machining material. Cast brass is more likely to be too soft to machine well. I just took apart a very old Sears cordless drill and liberated a 12V motor as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found an old 12V motor with some strange reduction gear which, many years ago was going to be a pottery wheel for kids. Some of this stuff has got to be useful even though 12V is not exactly ideal. An old automobile battery and a battery charger to keep it near full charge and you should be fine. And that would be a lot cheaper than a lab power supply of sufficient capacity to handle your tools. (Hmm ... if it is small enough, perhaps a motorcycle battery would be sufficient. I have a couple of power supplies - one should give steady 5 amps which as it turns out may not be enough. The other one should give 20 amps. I have not tried that one yet. But with an automotive battery, it would keep the battery charged, and the battery would handle the current to start the motor. (Of course, it really needs to be something like 14.4V to fully charge the battery. Note to self: Do not take motors apart without securing the brushes first! A good way to avoid doing anything productive for an hour... :-) Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Red-neck lathe v2.0
"DoN. Nichols" wrote in message ... Try to find "Modern Machine Shop Practice" (I forget whether that last word should have an 's' on the end. :-) Don't confuse it with "Machine Shop Practice" by Moultrecht which is a two-volume set. It is a good book set to have, but you won't find it for free. Who is the author? Hmm ... check your drill press. Put a round tip piece of stock in the drill chuck, put a flat piece of metal on the table, and bring the round end of the rod down on the piece of metal. Look carefully at the point of contact as you apply pressure. A lot of relatively inexpensive drill presses flex -- both the arm supporting the table and the head. This results in the contact point skidding towards you. This applies lateral force to the point -- and with the skinny point of a 1/8" center drill and it *will* break. A higher speed means that you are less likely to apply as much force to the spindle feed levers. I did not know that test. Will do. Very soft can be a problem -- it gums up the flutes of the bit. 360L brass has lead in it and is a bit harder than normal brass, but the lead lubricates the cuts, so it is a very nice machining material. Cast brass is more likely to be too soft to machine well. But its overwhelming redeeming quality is that it is cheap. I have a couple of power supplies - one should give steady 5 amps which as it turns out may not be enough. The other one should give 20 amps. I have not tried that one yet. But with an automotive battery, it would keep the battery charged, and the battery would handle the current to start the motor. (Of course, it really needs to be something like 14.4V to fully charge the battery. 13.7 V both of them. And a charger somewhere in the garage. In the end this is the way I may have to go: The first PS shuts down at start-up. I haven't worked out if it is the normal protection kicking itn at 7 Amps or a fault. I am measuring the current with a clamp meter and it does not even get up to 1 Amp. However, the protection is probably faster than the meter response... Anyway, that part has been put off for the moment: Today was the day to try applying a green patina to brass and soldering a brass ball to a candlestick cup. It is so easy to get distracted by things that are not immediately relevant but fun to play with... -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On 2008-09-01, Michael Koblic wrote:
"DoN. Nichols" wrote in message ... Try to find "Modern Machine Shop Practice" (I forget whether that last word should have an 's' on the end. :-) Don't confuse it with "Machine Shop Practice" by Moultrecht which is a two-volume set. It is a good book set to have, but you won't find it for free. Who is the author? Johshua Rose. A Google search on just the book title found this as the first hit: http://digital.lib.msu.edu/collections/index.cfm?TitleID=274 The publication date was: 1887-88 I know that there is a scanned and re-typeset version of it out there somewhere, because I have a copy here. It was at some university's project IIRC. "Project Gutenberg" Nope -- not there, it must have been some other scanning project. But I do know that the book is out there somewhere -- unless it has been shut down by the "copyright police". Hmm ... check your drill press. Put a round tip piece of stock in the drill chuck, put a flat piece of metal on the table, and bring the round end of the rod down on the piece of metal. Look carefully at the point of contact as you apply pressure. A lot of relatively inexpensive drill presses flex -- both the arm supporting the table and the head. This results in the contact point skidding towards you. This applies lateral force to the point -- and with the skinny point of a 1/8" center drill and it *will* break. A higher speed means that you are less likely to apply as much force to the spindle feed levers. I did not know that test. Will do. I've never heard of the test before. But I tried to come up with something which would demonstrate the problem if you have it. Very soft can be a problem -- it gums up the flutes of the bit. 360L brass has lead in it and is a bit harder than normal brass, but the lead lubricates the cuts, so it is a very nice machining material. Cast brass is more likely to be too soft to machine well. But its overwhelming redeeming quality is that it is cheap. Hmm ... depending on how much you need, you might look at the price for a 6' length of 360 brass 3/4" diameter. I get it from MSC from time to time. Last time I bought that it cost me $29.02 per bar, and I bought three of them for future needs. Hmm ... that was back in 2003, so it certainly will cost more now. But still, compare that with the cost of enough of those candlesticks to make up six feet -- and this is a free machining brass. I have a couple of power supplies - one should give steady 5 amps which as it turns out may not be enough. The other one should give 20 amps. I have not tried that one yet. But with an automotive battery, it would keep the battery charged, and the battery would handle the current to start the motor. (Of course, it really needs to be something like 14.4V to fully charge the battery. 13.7 V both of them. A bit low to reach a full charge in a lead-acid battery, though close to what a fully charged one will measure with no charging current and no load. And a charger somewhere in the garage. In the end this is the way I may have to go: The first PS shuts down at start-up. I haven't worked out if it is the normal protection kicking itn at 7 Amps or a fault. The starting current will be a lot higher than the current to keep it running. Hmm ... can you hook a large electrolytic capacitor across the supply to take that first surge? Something like 2000 to 10000 uF? I am measuring the current with a clamp meter and it does not even get up to 1 Amp. However, the protection is probably faster than the meter response... Which clamp-on meter? Many of them will only measure AC currents, not DC. Anyway, that part has been put off for the moment: Today was the day to try applying a green patina to brass and soldering a brass ball to a candlestick cup. Hmm ... back when he was still around, "Teenut" would answer the question of how to get a patina on brass by saying "Cat pee!". In particular, bury it in the cat's litter box for a few days. It is so easy to get distracted by things that are not immediately relevant but fun to play with... Why do you think that we are all here? Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Red-neck lathe v2.0
----- Original Message ----- From: "DoN. Nichols" Newsgroups: rec.crafts.metalworking Sent: Sunday, August 31, 2008 7:07 PM Subject: Red-neck lathe v2.0 Johshua Rose. A Google search on just the book title found this as the first hit: http://digital.lib.msu.edu/collections/index.cfm?TitleID=274 I will put it on the list. I have just printed out over 100 pages on "How to use a lathe". That should keep me going for a day or two. Hmm ... depending on how much you need, you might look at the price for a 6' length of 360 brass 3/4" diameter. I get it from MSC from time to time. Last time I bought that it cost me $29.02 per bar, and I bought three of them for future needs. Hmm ... that was back in 2003, so it certainly will cost more now. But still, compare that with the cost of enough of those candlesticks to make up six feet -- and this is a free machining brass. At about 25 cents a candle stick it is hard to beat. The starting current will be a lot higher than the current to keep it running. Hmm ... can you hook a large electrolytic capacitor across the supply to take that first surge? Something like 2000 to 10000 uF? I think it has one already. They are pretty standard on these regulated supplies. I shall look into it in a few days in more detail. I am measuring the current with a clamp meter and it does not even get up to 1 Amp. However, the protection is probably faster than the meter response... Which clamp-on meter? Many of them will only measure AC currents, not DC. This one does. Sears 82369. Hmm ... back when he was still around, "Teenut" would answer the question of how to get a patina on brass by saying "Cat pee!". In particular, bury it in the cat's litter box for a few days. Ah, but was it green, blue, red, brown or black? My guess is green is probably right as I am doing nearly the same. Without the cat. Today I was trying two different methods. I shall know tomorrow which one works better. I used to be able to do blue but I have not tried for some time. Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
On Sep 1, 1:23*am, "Michael Koblic" wrote:
----- Original Message ----- From: "DoN. Nichols" .... Which clamp-on meter? *Many of them will only measure AC currents, not DC. This one does. Sears 82369. Michael Koblic, I took a serious look at one of those, bought it and tried it on a lightbulb wire on my car in the parking lot. The reading was unstable because the zero drifted too quickly. I returned it. |
Red-neck lathe v2.0
On 2008-09-01, Michael Koblic wrote:
----- Original Message ----- From: "DoN. Nichols" Newsgroups: rec.crafts.metalworking Sent: Sunday, August 31, 2008 7:07 PM Subject: Red-neck lathe v2.0 Johshua Rose. A Google search on just the book title found this as the first hit: http://digital.lib.msu.edu/collections/index.cfm?TitleID=274 I will put it on the list. I have just printed out over 100 pages on "How to use a lathe". That should keep me going for a day or two. O.K. That is a good start. Which one -- the South Bend or the Atlas version? Each is somewhat focused on its own lathes, but most of what they say is truly general. Hmm ... depending on how much you need, you might look at the price for a 6' length of 360 brass 3/4" diameter. I get it from MSC from time to time. Last time I bought that it cost me $29.02 per bar, and I bought three of them for future needs. Hmm ... that was back in 2003, so it certainly will cost more now. But still, compare that with the cost of enough of those candlesticks to make up six feet -- and this is a free machining brass. At about 25 cents a candle stick it is hard to beat. O.K. How many vs how many you actually need? What about when you need more? If you try some 360 brass you will find it really nice to work. The starting current will be a lot higher than the current to keep it running. Hmm ... can you hook a large electrolytic capacitor across the supply to take that first surge? Something like 2000 to 10000 uF? I think it has one already. They are pretty standard on these regulated supplies. I shall look into it in a few days in more detail. Those with current limiting usually have the capacitor before the current sense, so it will be shut down by the starting spike. One connected to the external terminals will help a log for starting surges. I am measuring the current with a clamp meter and it does not even get up to 1 Amp. However, the protection is probably faster than the meter response... Which clamp-on meter? Many of them will only measure AC currents, not DC. This one does. Sears 82369. O.K. Hmm ... back when he was still around, "Teenut" would answer the question of how to get a patina on brass by saying "Cat pee!". In particular, bury it in the cat's litter box for a few days. Ah, but was it green, blue, red, brown or black? Green, IIRC. My guess is green is probably right as I am doing nearly the same. Without the cat. Today I was trying two different methods. I shall know tomorrow which one works better. O.K. I used to be able to do blue but I have not tried for some time. It will be interesting to hear what the results of the various methods are. Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Red-neck lathe v2.0
"Jim Wilkins" wrote in message ... On Sep 1, 1:23 am, "Michael Koblic" wrote: ----- Original Message ----- From: "DoN. Nichols" .... Which clamp-on meter? Many of them will only measure AC currents, not DC. This one does. Sears 82369. Michael Koblic, I took a serious look at one of those, bought it and tried it on a lightbulb wire on my car in the parking lot. The reading was unstable because the zero drifted too quickly. I returned it. ***I bought mine on EBay for a very low sum so I am more tolerant. However, having said that, I was quite impressed with it. I tested it across various ranges using fixed resistors and one of my power supplies. I tried to multiply the readings by coiling the lead and it showed the multiples just fine. Yes, you have to zero it before you start measuring. However, for measuring high currents it is better than almost anything else I have had before which had to be connected into a broken circuit. The internal resistances usually played havoc with the voltage, however small they were. There are quite a few more expensive ones but for someone who is happy with the current reading within 10% this one works for me. I bought it initially with a view to do some electroplating and found it useful incidentally when part of the house heating died. YMMV :-) -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
"DoN. Nichols" wrote in message ... O.K. That is a good start. Which one -- the South Bend or the Atlas version? Each is somewhat focused on its own lathes, but most of what they say is truly general. Birmingham (?) At about 25 cents a candle stick it is hard to beat. O.K. How many vs how many you actually need? What about when you need more? If you try some 360 brass you will find it really nice to work. I am sure you are right. However, with me it works almost the other way round: When I see something I ask myslef "Could it be useful?" and if the answer is yes, I offer the distressed widow a quarter to take that junk away... I will not be going to heaven. The starting current will be a lot higher than the current to keep it running. Hmm ... can you hook a large electrolytic capacitor across the supply to take that first surge? Something like 2000 to 10000 uF? I think it has one already. They are pretty standard on these regulated supplies. I shall look into it in a few days in more detail. Those with current limiting usually have the capacitor before the current sense, so it will be shut down by the starting spike. One connected to the external terminals will help a log for starting surges. Right. I need to establish first if there is a surge. A 2.5 ohm resistor should tell me. If it shuts down with that I have other problems. Green, IIRC. My guess is green is probably right as I am doing nearly the same. Without the cat. Today I was trying two different methods. I shall know tomorrow which one works better. O.K. I used to be able to do blue but I have not tried for some time. It will be interesting to hear what the results of the various methods are. Well, both sucked. Leaving it out in the open and respraying it produced a sort of spotty ugly rash. The big surprise was the "smothered" piece - not a tiny spot of anything! I cranked up the strength of the cat's pee and am repeating it just now with both pieces left out - they are two different kinds of brass. The one that refused to take any patina I *know* did so 10 years ago - but then it was blue patina: http://www.flickr.com/photos/2768312...7605638700703/ This is the green one I only did once: http://www.flickr.com/photos/2768312...7605638700703/ I was sloppy in those days, did not keep records and for the love of me cannot remember how I did it. I must photograph the various bits I am doing now. I do not think I am describing them very well. -- Michael Koblic, Campbell River, BC |
Red-neck lathe v2.0
"DoN. Nichols" wrote in message ... snip OK, see if you can view these: http://www.flickr.com/photos/2768312...7607066256337/ -- Michael Koblic, Campbell River, BC |
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