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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Those wretched cross-holes
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125"
diameter, 0.400" length). I clamped the cylinder by the ends (faced-off and therefore parallel) in a fairly substantial drill press vise, lined up the center and center-drilled first. Then I tried drilling the hole with a new 135 degree split point drill. The whole assembly started shaking, squealing and in spite of much cutting oil a lot of smoke developed. The drill run at appx. 800 rpm ( a big floor drill). I made it through by gritting my teeth and closing my eyes. Afterward I examined the drill with a magnifying glass and found what I think are small pieces of steel welded on. An identical drill from the same vendor has no difficulty drilling into steel otherwise. This is not the first time I have had a problem cross-drilling holes. The clamping arrangements were different but the ensuing effects were pretty much the same. I cannot understand why this is happening given the solid nature of clamping and all the other factors. I cannot see where flex would occur to produce the extreme form of chatter and subsequent rubbing (which is surely where the smoke and welding effects come from). It was suggested to me that the part gets distorted as the drilling progresses. It is certainly possible however, the noise etc. starts almost as soon as the drill hits the piece. I has occured to me that drilling round stock is essentially an interrupted cut until the drill has a chance to sink into the piece fully and engage the flutes 360 degrees. In that case, however, I would have expected the noise etc. to abate which did not happen. Perhaps by that time the drill is too damaged? What is it about drilling cross holes in small parts that causes these things to happen? I have tried different clamping arrangements in the past with essentially the same result. I could not really see any other way to clamp this piece differently considering its size and the size of the hole. To solve this I can only think of drilling with progressively increasing drill sizes (for 3/16" !!!?) or clamping the piece in a 4-jaw chuck and drill it in a lathe. Any other explanations or suggestions? -- Michael Koblic Campbell River, BC |
#2
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Those wretched cross-holes
Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125" diameter, 0.400" length). (...) Any other explanations or suggestions? I conjecture that the material is work hardening. What would happen if you used a stub length drill, pecked, and (importantly) used more feed pressure on the quill? Think Cole Drill Mode. --Winston |
#3
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Those wretched cross-holes
Winston fired this volley in
: What would happen if you used a stub length drill, pecked, and (importantly) used more feed pressure on the quill? And... turn the drill clockwise! GGG LLoyd |
#4
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Those wretched cross-holes
Lloyd E. Sponenburgh mentioned:
Winston fired this volley in : What would happen if you used a stub length drill, pecked, and (importantly) used more feed pressure on the quill? And... turn the drill clockwise! GGG LLoyd *Clockwise* you say? Thanks Lloyd, you may have saved me some time. --Winston -- Counter-clockwise, south of the equator? |
#5
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Those wretched cross-holes
"Michael Koblic" wrote:
What is it about drilling cross holes in small parts that causes these things to happen? How cheap are your drills? I tend to use PTD most of the time, My other thought, are you using 'mystery metal' ? Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller |
#6
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Those wretched cross-holes
Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125" diameter,... Ummm ... that leaves only a 1/16" "wall" to resist the clamping force. Maybe the part is collapsing a touch & binding on the bit. Just a WAG. Try this: clamp with the axis parallel to the vise jaws. 90 degrees to what you're doing. Bob |
#7
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Those wretched cross-holes
Lloyd E. Sponenburgh wrote:
Winston fired this volley in : What would happen if you used a stub length drill, pecked, and (importantly) used more feed pressure on the quill? And... turn the drill clockwise! GGG What direction is that? All my clocks are digital... |
#8
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Those wretched cross-holes
Wes wrote:
"Michael Koblic" wrote: What is it about drilling cross holes in small parts that causes these things to happen? How cheap are your drills? I tend to use PTD most of the time, My other thought, are you using 'mystery metal' ? Cheap. But I thought even a cheap drill should last one hole - this was a new drill! However, you may have a point: I have stub drills bought from KBC Tools which I keep for the use with my Taig lathe. Nothing fancy, 118 degrees points. Cut way better than the Canadian Tire drills. The metal should have been mild steel but I am beginning to wonder...I shall re-run the procedure with a certified mild steel and a stub drill as Winston suggested. I did peck and push... -- Michael Koblic Campbell River, BC |
#9
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Those wretched cross-holes
Michael Koblic wrote:
Wes wrote: "Michael Koblic" wrote: What is it about drilling cross holes in small parts that causes these things to happen? How cheap are your drills? I tend to use PTD most of the time, My other thought, are you using 'mystery metal' ? Cheap. But I thought even a cheap drill should last one hole - this was a new drill! However, you may have a point: I have stub drills bought from KBC Tools which I keep for the use with my Taig lathe. Nothing fancy, 118 degrees points. Cut way better than the Canadian Tire drills. The metal should have been mild steel but I am beginning to wonder...I shall re-run the procedure with a certified mild steel and a stub drill as Winston suggested. I did peck and push... We've all been in the situation where it becomes clear that the cutting lips have turned into a 'bearing'. Occasionally, one can rescue the situation by applying more force to break through the glasslike surface and the tool begins cutting once again. It's that large pressure which allows a Cole Drill to cut through stainless and tool steel using regular HSS bits. If you have sufficient force on the quill, the cutting lips always stay below the work hardened area and it never binds up (for that reason). You might be surprised how much force you can put on the quill with great results. --Winston |
#10
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Those wretched cross-holes
"Michael Koblic" fired this volley in
: What direction is that? All my clocks are digital... That's the opposite of Widdershins. LLoyd |
#11
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Those wretched cross-holes
In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: "Michael Koblic" fired this volley in : What direction is that? All my clocks are digital... That's the opposite of Widdershins. Just go opposite of the NASCAR drivers. |
#12
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Those wretched cross-holes
On 2009-09-22, Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125" diameter, 0.400" length). I clamped the cylinder by the ends (faced-off and therefore parallel) in a fairly substantial drill press vise, lined up the center and center-drilled first. Then I tried drilling the hole with a new 135 degree split point drill. The whole assembly started shaking, squealing and in spite of much cutting oil a lot of smoke developed. The drill run at appx. 800 rpm ( a big floor drill). Hmm ... about 39 SFM. What was the material you are drilling? And was it hardened steel or mild? I made it through by gritting my teeth and closing my eyes. Afterward I examined the drill with a magnifying glass and found what I think are small pieces of steel welded on. Sounds like hardened steel. An identical drill from the same vendor has no difficulty drilling into steel otherwise. The *same* steel? [ ... ] I cannot understand why this is happening given the solid nature of clamping and all the other factors. Note that the clamping may not be that solid. You are sure that the ends of the cylinder are parallel -- but the jaws of the vise may not be. A quick-and-dirty way to get more grip is to put some cardboard (not the corrugated stuff -- what used to come in shirts from the laundry) between the workpiece and the moving jaw, leaving the fixed jaw to define the position of the workpiece. Oh yes -- and the 3/16" drill bit is quite flexible too. A screw machine length drill bit would be shorter and thus less flexible. And who made the drill bit? If Chinese, it is a pure guess as to how good a steel is in the drill bit. If a US manufacturer like Cleveland, you are going to be more certain of the quality of the steel, and if you need it, you can go to a cobalt steel which is tougher (and more expensive). I cannot see where flex would occur to produce the extreme form of chatter and subsequent rubbing (which is surely where the smoke and welding effects come from). Can you identify what was shaking relative to what? In a drill press, there is flex in the column itself, the mounting of the table to the column, the mounting of the vise to the table, and usually the fit of the quill in the headstock casting. Was the vise firmly bolted to the drill press table? A milling machine is typically more rigid. And some floor standing drill presses may as well be made of freshly cooked noodles. :-) It was suggested to me that the part gets distorted as the drilling progresses. It is certainly possible however, the noise etc. starts almost as soon as the drill hits the piece. I has occured to me that drilling round stock is essentially an interrupted cut until the drill has a chance to sink into the piece fully and engage the flutes 360 degrees. In that case, however, I would have expected the noise etc. to abate which did not happen. Perhaps by that time the drill is too damaged? Again -- what steel were you drilling? A hardened mystery metal can be anything. What is it about drilling cross holes in small parts that causes these things to happen? It doesn't -- for me. But I know what metal I am drilling. I have tried different clamping arrangements in the past with essentially the same result. I could not really see any other way to clamp this piece differently considering its size and the size of the hole. To solve this I can only think of drilling with progressively increasing drill sizes (for 3/16" !!!?) or clamping the piece in a 4-jaw chuck and drill it in a lathe. Any other explanations or suggestions? Find out what the metal is which you are trying to drill, and how hardened it is. (How does a file do trying to cut it?) For some exotic metals, you should talk to the drill makers to see what they suggest. 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 --- |
#13
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Those wretched cross-holes
"DoN. Nichols" wrote in message ... Hmm ... about 39 SFM. What was the material you are drilling? And was it hardened steel or mild? A mystery metal which I was probably wrongly lead to believe was mild steel. An identical drill from the same vendor has no difficulty drilling into steel otherwise. The *same* steel? A different one. I cannot understand why this is happening given the solid nature of clamping and all the other factors. Note that the clamping may not be that solid. You are sure that the ends of the cylinder are parallel -- but the jaws of the vise may not be. A quick-and-dirty way to get more grip is to put some cardboard (not the corrugated stuff -- what used to come in shirts from the laundry) between the workpiece and the moving jaw, leaving the fixed jaw to define the position of the workpiece. Ah! That is useful...Thanks. Oh yes -- and the 3/16" drill bit is quite flexible too. A screw machine length drill bit would be shorter and thus less flexible. Yes, that appears to be the consensus. And who made the drill bit? If Chinese, it is a pure guess as to how good a steel is in the drill bit. If a US manufacturer like Cleveland, you are going to be more certain of the quality of the steel, and if you need it, you can go to a cobalt steel which is tougher (and more expensive). I cannot imagine that Canadian Tire sells anything but Chinese. They look pretty though... I cannot see where flex would occur to produce the extreme form of chatter and subsequent rubbing (which is surely where the smoke and welding effects come from). Can you identify what was shaking relative to what? In a drill press, there is flex in the column itself, the mounting of the table to the column, the mounting of the vise to the table, and usually the fit of the quill in the headstock casting. In the end everything was shaking including myself. It is worth noting that I had a similar experience with a similar shape in my mini-mill but the details are now obscure, especially the nature of the metal. Was the vise firmly bolted to the drill press table? I should remember but I do not. Somehow I think it was as I would normally clamp this sort of work but I do not always bolt the vise for a straightforward small hole. This, of course, was not it. A milling machine is typically more rigid. And some floor standing drill presses may as well be made of freshly cooked noodles. :-) It is what it is. Bridgeport it ain't. snip The experiment is to be repeated with some changes and bona fide mild steel. -- Michael Koblic Campbell River, BC |
#14
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Those wretched cross-holes
On Sep 24, 2:50*am, "Michael Koblic" wrote:
.... The experiment is to be repeated with some changes and bona fide mild steel. -- Michael Koblic Campbell River, BC In my experience scrap-yard mystery metal and some hardware store CRS machine considerably better after annealing. Often the quickie 'water anneal' is enough; heat it red, quench when the glow disappears. Milling or filing a flat makes cross-drilling easier, at least until the bit breaks through and grabs. A few times I've used a center drill beyond its intended depth to make a parallel-sided starting hole. jsw |
#15
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Those wretched cross-holes
On 2009-09-24, Michael Koblic wrote:
"DoN. Nichols" wrote in message ... Hmm ... about 39 SFM. What was the material you are drilling? And was it hardened steel or mild? A mystery metal which I was probably wrongly lead to believe was mild steel. BTW -- if you want a really nice steel to machine (as long as you don't need to harden it), look for some 12L14 (very free turning leaded mild steel, and it produces a beautiful finish. An identical drill from the same vendor has no difficulty drilling into [ ... ] And who made the drill bit? If Chinese, it is a pure guess as to how good a steel is in the drill bit. If a US manufacturer like Cleveland, you are going to be more certain of the quality of the steel, and if you need it, you can go to a cobalt steel which is tougher (and more expensive). I cannot imagine that Canadian Tire sells anything but Chinese. They look pretty though... Pretty as in "gold colored". This means that they have been TiN coated (Titanium Nitride, not the metal tin). If the surface appears to be somewhat frosted under the coating, it is likely to be a very poor metal. If the surface appears to have been polished before the TiN coating, it is more likely to be a good steel -- which they took the time to work with properly when fabricating the drill bit. [ ... ] Can you identify what was shaking relative to what? In a drill press, there is flex in the column itself, the mounting of the table to the column, the mounting of the vise to the table, and usually the fit of the quill in the headstock casting. In the end everything was shaking including myself. Some things can be checked by touch. For example, with one hand, touch one finger to the vise and another to the table. This makes it fairly easy to tell if there is motion there. A similar test can detect motion of the workpiece in the vise -- but be careful in case the workpiece comes loose and starts spinning. Also -- touch one finger to the headstock casting, and another to the side of the quill to see if that is loose. [ ... ] A milling machine is typically more rigid. And some floor standing drill presses may as well be made of freshly cooked noodles. :-) It is what it is. Bridgeport it ain't. But something like a radial drill press is almost as rigid as a Bridgeport -- but much larger and heavier. [ ... ] The experiment is to be repeated with some changes and bona fide mild steel. Try 12L14 if you can get some. You will find it a true pleasure to machine. 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 --- |
#16
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Those wretched cross-holes
"DoN. Nichols" wrote in message ... On 2009-09-24, Michael Koblic wrote: "DoN. Nichols" wrote in message ... Hmm ... about 39 SFM. What was the material you are drilling? And was it hardened steel or mild? A mystery metal which I was probably wrongly lead to believe was mild steel. BTW -- if you want a really nice steel to machine (as long as you don't need to harden it), look for some 12L14 (very free turning leaded mild steel, and it produces a beautiful finish. A quick look tells me the local supplier carries only 1.5" diameter rods in 12L14. evryone sells them in various diameters and lengths for peanuts. Including Amazon! But nobody ships to Canada. Some more local research is called for. More doughnuts.. An identical drill from the same vendor has no difficulty drilling into [ ... ] And who made the drill bit? If Chinese, it is a pure guess as to how good a steel is in the drill bit. If a US manufacturer like Cleveland, you are going to be more certain of the quality of the steel, and if you need it, you can go to a cobalt steel which is tougher (and more expensive). I cannot imagine that Canadian Tire sells anything but Chinese. They look pretty though... Pretty as in "gold colored". This means that they have been TiN coated (Titanium Nitride, not the metal tin). If the surface appears to be somewhat frosted under the coating, it is likely to be a very poor metal. If the surface appears to have been polished before the TiN coating, it is more likely to be a good steel -- which they took the time to work with properly when fabricating the drill bit. I kind of gathered they were TiN. however, to my untrained eye they look shiny. I do not have anything high quality to compare - those are covered with black oxide. [ ... ] Can you identify what was shaking relative to what? In a drill press, there is flex in the column itself, the mounting of the table to the column, the mounting of the vise to the table, and usually the fit of the quill in the headstock casting. In the end everything was shaking including myself. Some things can be checked by touch. For example, with one hand, touch one finger to the vise and another to the table. This makes it fairly easy to tell if there is motion there. A similar test can detect motion of the workpiece in the vise -- but be careful in case the workpiece comes loose and starts spinning. Also -- touch one finger to the headstock casting, and another to the side of the quill to see if that is loose. I will pay attention next time I run this test. I hope to eliminate this kerfaffle with a clamping jig. Sounds like clamping by the ends and leaving 1/16" inch to support the hole is probably not a thing to do. [ ... ] A milling machine is typically more rigid. And some floor standing drill presses may as well be made of freshly cooked noodles. :-) It is what it is. Bridgeport it ain't. But something like a radial drill press is almost as rigid as a Bridgeport -- but much larger and heavier. Well, it ain't that either...:-) [ ... ] The experiment is to be repeated with some changes and bona fide mild steel. Try 12L14 if you can get some. You will find it a true pleasure to machine. There is a Zen-like quality to making steel wool on the Taig. When things go badly elsewhere, I try and turn something on the Taig. Like a security blanket. Funny, the mill does not have the same effect. I still experience a child-like wonder when I center drill a rod and the hole is...in the center! -- Michael Koblic Campbell River, BC |
#17
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Those wretched cross-holes
On Fri, 25 Sep 2009 12:45:33 -0700, "Michael Koblic"
wrote: A quick look tells me the local supplier carries only 1.5" diameter rods in 12L14. evryone sells them in various diameters and lengths for peanuts. Including Amazon! But nobody ships to Canada. Some more local research is called for. More doughnuts.. Whatever you do, do not resort to using the 1"- bar from someone's disused weight set. That is some of the worst machining material I have ever encountered - worse even than re-bar from Mexico. Gerry :-)} London, Canada |
#18
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Those wretched cross-holes
Gerald Miller wrote:
Whatever you do, do not resort to using the 1"- bar from someone's disused weight set. That is some of the worst machining material I have ever encountered - worse even than re-bar from Mexico. Ummm ... I've used one of those weight bars & it was OK. Thinking that maybe it was an exception, I just went down & cut off a piece of another one that I have. On the lathe with an HSS bit & 100 fpm or so it *was* crappy. Bad tearing. I tried a carbide bit at 400 fpm & it was pretty good: http://home.comcast.net/~bobengelhardt/WeightBar.jpg That's a finishing pass of about .003 DOC & .003 feed (the ruler is mm). Once again it goes to show that YMMV, Bob |
#19
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Those wretched cross-holes
On 2009-09-25, Michael Koblic wrote:
"DoN. Nichols" wrote in message [ ... ] BTW -- if you want a really nice steel to machine (as long as you don't need to harden it), look for some 12L14 (very free turning leaded mild steel, and it produces a beautiful finish. A quick look tells me the local supplier carries only 1.5" diameter rods in 12L14. evryone sells them in various diameters and lengths for peanuts. Including Amazon! But nobody ships to Canada. Some more local research is called for. Hmm ... 1.5" diameter is probably a pretty good size for some projects -- especially lathe ones. You'll want to get as long a rod as you can afford/(transport home) and have some way to cut it. The typical 4x6" horizontal/vertical bandsaw works well for this. I've got both 1-1/2" round 12L14 and whatever the hex size is which just barely fits through the 1-3/8" spindle bore. Grips nicely in the 3-jaw chuck. Of course, for smaller projects, having something closer to the desired size is helpful -- in spite of a machinist friend at work who always used to claim "the best metal is in the middle" as he took a 3" chuck of round brass stock to make a 1/2" diameter part. Lots of chips. :-) [ ... ] And who made the drill bit? If Chinese, it is a pure guess as to how good a steel is in the drill bit. If a US manufacturer like Cleveland, you are going to be more certain of the quality of the steel, and if you need it, you can go to a cobalt steel which is tougher (and more expensive). I cannot imagine that Canadian Tire sells anything but Chinese. They look pretty though... Pretty as in "gold colored". This means that they have been TiN coated (Titanium Nitride, not the metal tin). If the surface appears to be somewhat frosted under the coating, it is likely to be a very poor metal. If the surface appears to have been polished before the TiN coating, it is more likely to be a good steel -- which they took the time to work with properly when fabricating the drill bit. I kind of gathered they were TiN. however, to my untrained eye they look shiny. I do not have anything high quality to compare - those are covered with black oxide. O.K. Yes the finish varies with the intended function. Black oxide is nice for some materials, Polished parabolic flutes nicer for others, TiN coated for letting the chips flow out from yet others. My usual bits (the 118 piece set of number/letter/fractional and the cobalt steel set of number-size screw machine length bits are both polished, though not parabolic flute. The two sets which make up my stock of metric sizes are black oxide, and I don't use them often enough to have an opinion for my usual materials. My metric tap-and-drill set has everything TiN coated, but Cleveland brand bits and taps, so I know that they are good. The 61-80 number sized set is polished -- if I examine them in a microscope. Otherwise, they hard enough to even see. :-) [ ... ] Some things can be checked by touch. For example, with one hand, touch one finger to the vise and another to the table. This makes it fairly easy to tell if there is motion there. A similar test can detect motion of the workpiece in the vise -- but be careful in case the workpiece comes loose and starts spinning. Also -- touch one finger to the headstock casting, and another to the side of the quill to see if that is loose. I will pay attention next time I run this test. I hope to eliminate this kerfaffle with a clamping jig. Sounds like clamping by the ends and leaving 1/16" inch to support the hole is probably not a thing to do. Was the workpiece hollow or solid metal? If solid, check whether your drill press vise has a horizontal V-groove, ideally with a Vertical one meeting it in the fixed jaw. These give a good grip, and the vertical V-groove gives access to the area which you want to cross-drill. (For that matter, you can take a short piece of material the same diameter, face off the ends and drill through the center just the size to accept the drill bit which you intend to use, and drop it down the vertical V-groove after inserting the workpiece in the horizontal V-groove. Then Tighten the vise and drill guided by the existing center hole. (If you're going to drill a lot of holes like this, make the guide out of drill rod, and harden it after machining (facing and drilling), so it will last longer. Probably a good idea to use a countersink to chamfer the hole at the upper end at least -- and probably both ends so you don't have to worry about which end is up. [ ... ] The experiment is to be repeated with some changes and bona fide mild steel. Try 12L14 if you can get some. You will find it a true pleasure to machine. There is a Zen-like quality to making steel wool on the Taig. When things go badly elsewhere, I try and turn something on the Taig. Like a security blanket. Funny, the mill does not have the same effect. I still experience a child-like wonder when I center drill a rod and the hole is...in the center! What you want for the Zen quality is a small shaper -- say a 7" one. You sit there watching the ram move in and out, with the workpiece moving sideways just a little during each backstroke. And the tool is a simple HSS lathe bit which you can grind as you wish. 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 --- |
#20
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Those wretched cross-holes
"Bob Engelhardt" wrote in message ... Gerald Miller wrote: Whatever you do, do not resort to using the 1"- bar from someone's disused weight set. That is some of the worst machining material I have ever encountered - worse even than re-bar from Mexico. Ummm ... I've used one of those weight bars & it was OK. Thinking that maybe it was an exception, I just went down & cut off a piece of another one that I have. On the lathe with an HSS bit & 100 fpm or so it *was* crappy. Bad tearing. I tried a carbide bit at 400 fpm & it was pretty good: http://home.comcast.net/~bobengelhardt/WeightBar.jpg That's a finishing pass of about .003 DOC & .003 feed (the ruler is mm). Once again it goes to show that YMMV, Aaargh! Do no start me off! I just tried some carbide inserts with miserable results. It seems Taig is too small for carbide even if cunningly sold in 1/4" tool-holders. -- Michael Koblic Campbell River, BC |
#21
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Those wretched cross-holes
"DoN. Nichols" wrote in message ... [ ... ] Hmm ... 1.5" diameter is probably a pretty good size for some projects -- especially lathe ones. You'll want to get as long a rod as you can afford/(transport home) and have some way to cut it. The typical 4x6" horizontal/vertical bandsaw works well for this. I've got both 1-1/2" round 12L14 and whatever the hex size is which just barely fits through the 1-3/8" spindle bore. Grips nicely in the 3-jaw chuck. Of course, for smaller projects, having something closer to the desired size is helpful -- in spite of a machinist friend at work who always used to claim "the best metal is in the middle" as he took a 3" chuck of round brass stock to make a 1/2" diameter part. Lots of chips. :-) Hacksawing is one of the ways I get exercise. However, even with such exemplary lifestyle I doubt I shall live long enough to machine anything out of a 1.5" bar on the Taig, 0.005" at a time. I made further enquiries with that wonder of a company, Fastenal. Their catalog shows only the 1.5" round in 12L14. A phone call to the branch here in town revealed that they could get 3/8", "but 10 feet length would be below the minimum order". The same company, branch 50 km away, can apparently sell single 3 ft rods of 3/8" just under $8.Which in US sells under $3. It's back to the doughnuts! [ ... ] O.K. Yes the finish varies with the intended function. Black oxide is nice for some materials, Polished parabolic flutes nicer for others, TiN coated for letting the chips flow out from yet others. My usual bits (the 118 piece set of number/letter/fractional and the cobalt steel set of number-size screw machine length bits are both polished, though not parabolic flute. The two sets which make up my stock of metric sizes are black oxide, and I don't use them often enough to have an opinion for my usual materials. My metric tap-and-drill set has everything TiN coated, but Cleveland brand bits and taps, so I know that they are good. The 61-80 number sized set is polished -- if I examine them in a microscope. Otherwise, they hard enough to even see. :-) I got a black oxide set of 118 degree point stub drills specifically for the Taig. They cut incomparably better in steel than the CT TiN. The chips come out of the holes ever so easily even if the hole is quite deep. The TiN cut for about 1/2" and then the chips stop flowing and the rubbing starts (I am talking certified mild steel now). No amount of lubricant seems to change that. [ ... ] Was the workpiece hollow or solid metal? If solid, check whether your drill press vise has a horizontal V-groove, ideally with a Vertical one meeting it in the fixed jaw. These give a good grip, and the vertical V-groove gives access to the area which you want to cross-drill. (For that matter, you can take a short piece of material the same diameter, face off the ends and drill through the center just the size to accept the drill bit which you intend to use, and drop it down the vertical V-groove after inserting the workpiece in the horizontal V-groove. Then Tighten the vise and drill guided by the existing center hole. (If you're going to drill a lot of holes like this, make the guide out of drill rod, and harden it after machining (facing and drilling), so it will last longer. Probably a good idea to use a countersink to chamfer the hole at the upper end at least -- and probably both ends so you don't have to worry about which end is up. It was solid. Yes, there is a horizontal v-grove but the 5/16 diameter cylinder all but disappears in it and the vertical groove is not large enough to allow 3/16 drill through. Also, I am not sure how one would center the drill if the piece were held this way. Can you be certain that the vertical groove always centers automatically on the diameter of the piece held in the cross-grove (which would be mandatory if one used the guide made as you suggested)? I used to drill similar pieces held in the horizontal v-grove *before* I cut them off. I tried to let them stick out to the side of the vise which allowed for proper centering and center drilling. Even then, the problem was that one had to let the piece stick out quite a bit to be able to get the chuck down to the piece without the top of the vise interfering. This was all well and good for center drilling but when one came to use the twist drill more chatter and rubbing resulted. I tried making an improvised machinist jack to support the end sticking out but it did not seem to help all that much. Mind you, it was a pretty miserable excuse for jack ! With the advent of Taig I was hoping that these problems were a thing of the past now that I could face off the opposite ends of the cylinder. Apparently not so. [ ... ] What you want for the Zen quality is a small shaper -- say a 7" one. You sit there watching the ram move in and out, with the workpiece moving sideways just a little during each backstroke. And the tool is a simple HSS lathe bit which you can grind as you wish. Due to recession I shall have to stay with the Taig and chanting a mantra. BTW I wonder if one can make a mandala out of the steel wool and assorted chips. -- Michael Koblic Campbell River, BC |
#22
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Those wretched cross-holes
If the vise's vertical and horizontal V-grooves are the same dimensions (as
they are in most vise jaw plates), then clamping same-diameter pieces in each groove will keep the center lines of both workpieces aligned. Drill bushings such as those suggested by DoN will keep the drill centered on the horizontal piece's center line as long as the two stock diameters are the same. BTW, if the cross hole needs to be near the end of a workpiece, drilling the hole with this method will likely work better if the hole is drilled before cutting the length of the workpiece. The longer length of stock held in the horizontal V-groove will be supported by the entire width of the horizontal groove, eliminating the possibility of the part shifting if it were only supported by about half of the V-groove (particularly in smaller vises). The increased gripping area should insure a smooth drilling action with no surprises. -- WB .......... metalworking projects www.kwagmire.com/metal_proj.html "Michael Koblic" wrote in message ... Can you be certain that the vertical groove always centers automatically on the diameter of the piece held in the cross-grove (which would be mandatory if one used the guide made as you suggested)? |
#23
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Those wretched cross-holes
On Fri, 25 Sep 2009 22:46:23 -0700, "Michael Koblic"
wrote: "Bob Engelhardt" wrote in message ... Gerald Miller wrote: Whatever you do, do not resort to using the 1"- bar from someone's disused weight set. That is some of the worst machining material I have ever encountered - worse even than re-bar from Mexico. Ummm ... I've used one of those weight bars & it was OK. Thinking that maybe it was an exception, I just went down & cut off a piece of another one that I have. On the lathe with an HSS bit & 100 fpm or so it *was* crappy. Bad tearing. I tried a carbide bit at 400 fpm & it was pretty good: http://home.comcast.net/~bobengelhardt/WeightBar.jpg That's a finishing pass of about .003 DOC & .003 feed (the ruler is mm). Once again it goes to show that YMMV, Aaargh! Do no start me off! I just tried some carbide inserts with miserable results. It seems Taig is too small for carbide even if cunningly sold in 1/4" tool-holders. SB9A is pretty much too small/light for carbide unless it is honed and polished. Gerry :-)} London, Canada |
#24
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Those wretched cross-holes
On Fri, 25 Sep 2009 23:15:44 -0700, "Michael Koblic"
wrote: "DoN. Nichols" wrote in message ... [ ... ] Hmm ... 1.5" diameter is probably a pretty good size for some projects -- especially lathe ones. You'll want to get as long a rod as you can afford/(transport home) and have some way to cut it. The typical 4x6" horizontal/vertical bandsaw works well for this. I've got both 1-1/2" round 12L14 and whatever the hex size is which just barely fits through the 1-3/8" spindle bore. Grips nicely in the 3-jaw chuck. Of course, for smaller projects, having something closer to the desired size is helpful -- in spite of a machinist friend at work who always used to claim "the best metal is in the middle" as he took a 3" chuck of round brass stock to make a 1/2" diameter part. Lots of chips. :-) Hacksawing is one of the ways I get exercise. Couple months back I picked up a Skill reciprocating saw for a buck. It was missing the blade holder but some creative modification to a 1/2" drive socket and its back in business. Haven't actually tried it out yet but have high hopes - been too busy straightening the output shaft on a 4HP B&S with a 4 lb. hammer, etc. etc. However, even with such exemplary lifestyle I doubt I shall live long enough to machine anything out of a 1.5" bar on the Taig, 0.005" at a time. I made further enquiries with that wonder of a company, Fastenal. Their catalog shows only the 1.5" round in 12L14. A phone call to the branch here in town revealed that they could get 3/8", "but 10 feet length would be below the minimum order". The same company, branch 50 km away, can apparently sell single 3 ft rods of 3/8" just under $8.Which in US sells under $3. It's back to the doughnuts! [ ... ] O.K. Yes the finish varies with the intended function. Black oxide is nice for some materials, Polished parabolic flutes nicer for others, TiN coated for letting the chips flow out from yet others. My usual bits (the 118 piece set of number/letter/fractional and the cobalt steel set of number-size screw machine length bits are both polished, though not parabolic flute. The two sets which make up my stock of metric sizes are black oxide, and I don't use them often enough to have an opinion for my usual materials. My metric tap-and-drill set has everything TiN coated, but Cleveland brand bits and taps, so I know that they are good. The 61-80 number sized set is polished -- if I examine them in a microscope. Otherwise, they hard enough to even see. :-) I got a black oxide set of 118 degree point stub drills specifically for the Taig. They cut incomparably better in steel than the CT TiN. The chips come out of the holes ever so easily even if the hole is quite deep. The TiN cut for about 1/2" and then the chips stop flowing and the rubbing starts (I am talking certified mild steel now). No amount of lubricant seems to change that. [ ... ] Was the workpiece hollow or solid metal? If solid, check whether your drill press vise has a horizontal V-groove, ideally with a Vertical one meeting it in the fixed jaw. These give a good grip, and the vertical V-groove gives access to the area which you want to cross-drill. (For that matter, you can take a short piece of material the same diameter, face off the ends and drill through the center just the size to accept the drill bit which you intend to use, and drop it down the vertical V-groove after inserting the workpiece in the horizontal V-groove. Then Tighten the vise and drill guided by the existing center hole. (If you're going to drill a lot of holes like this, make the guide out of drill rod, and harden it after machining (facing and drilling), so it will last longer. Probably a good idea to use a countersink to chamfer the hole at the upper end at least -- and probably both ends so you don't have to worry about which end is up. It was solid. Yes, there is a horizontal v-grove but the 5/16 diameter cylinder all but disappears in it and the vertical groove is not large enough to allow 3/16 drill through. Also, I am not sure how one would center the drill if the piece were held this way. Can you be certain that the vertical groove always centers automatically on the diameter of the piece held in the cross-grove (which would be mandatory if one used the guide made as you suggested)? I used to drill similar pieces held in the horizontal v-grove *before* I cut them off. I tried to let them stick out to the side of the vise which allowed for proper centering and center drilling. Even then, the problem was that one had to let the piece stick out quite a bit to be able to get the chuck down to the piece without the top of the vise interfering. This was all well and good for center drilling but when one came to use the twist drill more chatter and rubbing resulted. I tried making an improvised machinist jack to support the end sticking out but it did not seem to help all that much. Mind you, it was a pretty miserable excuse for jack ! With the advent of Taig I was hoping that these problems were a thing of the past now that I could face off the opposite ends of the cylinder. Apparently not so. [ ... ] What you want for the Zen quality is a small shaper -- say a 7" one. You sit there watching the ram move in and out, with the workpiece moving sideways just a little during each backstroke. And the tool is a simple HSS lathe bit which you can grind as you wish. Due to recession I shall have to stay with the Taig and chanting a mantra. BTW I wonder if one can make a mandala out of the steel wool and assorted chips. Gerry :-)} London, Canada |
#25
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Those wretched cross-holes
"Gerald Miller" wrote in message ... SB9A is pretty much too small/light for carbide unless it is honed and polished. SB9A is a 9x19, yes? |
#26
Posted to rec.crafts.metalworking
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Those wretched cross-holes
On Sat, 26 Sep 2009 19:02:05 -0700, "Michael Koblic"
wrote: "Gerald Miller" wrote in message .. . SB9A is pretty much too small/light for carbide unless it is honed and polished. SB9A is a 9x19, yes? 9x depends upon bed length, my 3' bed gives about 19" between centres. Gerry :-)} London, Canada |
#27
Posted to rec.crafts.metalworking
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Those wretched cross-holes
On Sat, 26 Sep 2009 22:14:39 -0400, Gerald Miller
wrote: On Sat, 26 Sep 2009 19:02:05 -0700, "Michael Koblic" wrote: "Gerald Miller" wrote in message . .. SB9A is pretty much too small/light for carbide unless it is honed and polished. SB9A is a 9x19, yes? 9x depends upon bed length, my 3' bed gives about 19" between centres. Gerry :-)} London, Canada See: http://www.lathes.co.uk/southbend9-inch/ I should have said 17" Gerry :-)} London, Canada |
#28
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Those wretched cross-holes
On 2009-09-26, Michael Koblic wrote:
"DoN. Nichols" wrote in message ... [ ... ] Hmm ... 1.5" diameter is probably a pretty good size for some projects -- especially lathe ones. You'll want to get as long a rod as you can afford/(transport home) and have some way to cut it. The typical 4x6" horizontal/vertical bandsaw works well for this. [ ... ] Hacksawing is one of the ways I get exercise. Well ... with 1.5" diameter, you may get tired of that fairly quickly. And the H/V bandsaw makes a cut closer to square than a hacksaw typically does. You still have to face it to clean up the cut, but there is less to remove after the bandsaw has done its job. However, even with such exemplary lifestyle I doubt I shall live long enough to machine anything out of a 1.5" bar on the Taig, 0.005" at a time. I made further enquiries with that wonder of a company, Fastenal. Their catalog shows only the 1.5" round in 12L14. A phone call to the branch here in town revealed that they could get 3/8", "but 10 feet length would be below the minimum order". The same company, branch 50 km away, can apparently sell single 3 ft rods of 3/8" just under $8.Which in US sells under $3. Hmm ... if they have to order it in, yes, they want to sell it all at once to make it worth their while. As for the 3' rods -- get *one* (if that branch does not also have a minimum order) and see what it is like to use it. I think that you'll find that your Taig can cut deeper than before. And also get some 360L brass as well. It is lovely to cut too. [ ... ] O.K. Yes the finish varies with the intended function. Black oxide is nice for some materials, Polished parabolic flutes nicer for others, TiN coated for letting the chips flow out from yet others. My usual bits (the 118 piece set of number/letter/fractional and the cobalt steel set of number-size screw machine length bits are both polished, though not parabolic flute. The two sets which make up my stock of metric sizes are black oxide, and I don't use them often enough to have an opinion for my usual materials. My metric tap-and-drill set has everything TiN coated, but Cleveland brand bits and taps, so I know that they are good. [ ... ] I got a black oxide set of 118 degree point stub drills specifically for the Taig. They cut incomparably better in steel than the CT TiN. The chips come out of the holes ever so easily even if the hole is quite deep. The TiN cut for about 1/2" and then the chips stop flowing and the rubbing starts (I am talking certified mild steel now). No amount of lubricant seems to change that. I think that this says that the Chinese bit is "certified mild steel" as well. :-) As for "lubricant" -- what are you using? You really don't want to lubricate -- you want to cool (remove heat from the tool and the workpiece), and to chemically aid the peeling of the metal away from the workpiece. Things like Rigid high-sulfur pipe threading oil will work sell for the purpose. [ ... ] Was the workpiece hollow or solid metal? If solid, check whether your drill press vise has a horizontal V-groove, ideally with a Vertical one meeting it in the fixed jaw. These give a good grip, and the vertical V-groove gives access to the area which you want to cross-drill. (For that matter, you can take a short piece of material the same diameter, face off the ends and drill through the center just the size to accept the drill bit which you intend to use, and drop it down the vertical V-groove after inserting the workpiece in the horizontal V-groove. Then Tighten the vise and drill guided by the existing center hole. (If you're going to drill a lot of holes like this, make the guide out of drill rod, and harden it after machining (facing and drilling), so it will last longer. Probably a good idea to use a countersink to chamfer the hole at the upper end at least -- and probably both ends so you don't have to worry about which end is up. It was solid. Yes, there is a horizontal v-grove but the 5/16 diameter cylinder Hmm ... the fact that you keep calling it a "cylinder" instead of a "rod" is probably why others in this thread have assumed that what you are drilling is hollow and commented on how the bit behaves as it breaks through the inner walls. Try calling it "rod stock" and people won't make that assumption. all but disappears in it and the vertical groove is not large enough to allow 3/16 drill through. Also, I am not sure how one would center the drill if the piece were held this way. Can you be certain that the vertical groove always centers automatically on the diameter of the piece held in the cross-grove (which would be mandatory if one used the guide made as you suggested)? Well ... Both V ways were probably cut on the same machine, so the depth should be the same. A quick check is whether both the horizontal workpiece and the vertical guide (which for test purposes can simply be another cutoff of the same stock) are firmly gripped by the vise at the same time. It probably does not hurt to add paper between the moving jaw and the workpiece and guide to make up for the jaw tilting slightly as it is tightened. I used to drill similar pieces held in the horizontal v-grove *before* I cut them off. I tried to let them stick out to the side of the vise which allowed for proper centering and center drilling. Even then, the problem was that one had to let the piece stick out quite a bit to be able to get the chuck down to the piece without the top of the vise interfering. Two identical vises, clamping on either side of the area where you intend to drill. If you are supporting only at one end, consider that if the distance from the clamp (vise) to the place where you are drilling is over four times the diameter of the workpiece, then it will flex. (Same rule should be used for work held in the chuck of the lathe. If it extends beyond that length -- add support by a live center in the tailstock to make it more rigid. This was all well and good for center drilling but when one came to use the twist drill more chatter and rubbing resulted. I tried making an improvised machinist jack to support the end sticking out but it did not seem to help all that much. Mind you, it was a pretty miserable excuse for jack ! A chunk of round stock, drilled and tapped down the center to accept a bolt. Turn a point on the head of the bolt, and make a piece with a center hole in one side, and a V going across the center of the center hole )look for it to break through there) can be used to support. The greater the diameter of the base of the jack, the more stable it will be. With the advent of Taig I was hoping that these problems were a thing of the past now that I could face off the opposite ends of the cylinder. Apparently not so. Use the cardboard for crush space to increase the grip. [ ... ] What you want for the Zen quality is a small shaper -- say a 7" one. You sit there watching the ram move in and out, with the workpiece moving sideways just a little during each backstroke. And the tool is a simple HSS lathe bit which you can grind as you wish. Due to recession I shall have to stay with the Taig and chanting a mantra. BTW I wonder if one can make a mandala out of the steel wool and assorted chips. Well ... you are unlikely to be presented with the opportunity to buy a new 7" shaper. You have to luck into a well used one. Nobody seems to make them any more. 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 --- |
#29
Posted to rec.crafts.metalworking
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Those wretched cross-holes
On 2009-09-26, Michael Koblic wrote:
"Bob Engelhardt" wrote in message ... [ ... ] On the lathe with an HSS bit & 100 fpm or so it *was* crappy. Bad tearing. I tried a carbide bit at 400 fpm & it was pretty good: http://home.comcast.net/~bobengelhardt/WeightBar.jpg That's a finishing pass of about .003 DOC & .003 feed (the ruler is mm). Once again it goes to show that YMMV, Aaargh! Do no start me off! I just tried some carbide inserts with miserable results. It seems Taig is too small for carbide even if cunningly sold in 1/4" tool-holders. 1/4" shank is too small for carbide insert tools. You need to make a toolpost which will hold larger tool shanks. And any holder sold with 1/4" shanks probably comes with the cheap carbide inserts which are too thin, too weak, a poor grade of carbide, and with no carbide anvils supporting the carbide inserts. And most inserts are not really sharp enough for them to work well in the Taig. Especially bad are the TiN coated carbide inserts, as the coating dulls the edge a bit even if it was originally formed with a good edge. BTW -- if you want to see something which makes the Taig look rigid, try an old Unimat SL-1000 or DB-200. Those use a pair of mild steel rods as the ways, and they *bend* under cutting forces. This was *my* first lathe at home. And I now have the Taig, which I consider much more rigid -- though I also have other lathes, up to a 12x24" Clausing. :-) 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 --- |
#30
Posted to rec.crafts.metalworking
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Those wretched cross-holes
On Sun, 27 Sep 2009 04:03:59 +0000, DoN. Nichols wrote:
On 2009-09-26, Michael Koblic ... wrote: .... I used to drill similar pieces held in the horizontal v-grove *before* I cut them off. I tried to let them stick out to the side of the vise which allowed for proper centering and center drilling. Even then, the problem was that one had to let the piece stick out quite a bit to be able to get the chuck down to the piece without the top of the vise interfering. Two identical vises, clamping on either side of the area where you intend to drill. If you are supporting only at one end, consider that if the distance from the clamp (vise) to the place where you are drilling is over four times the diameter of the workpiece, then it will flex. (Same rule should be used for work held in the chuck of the lathe. [...] OP 21 Sept 2009, Michael Koblic originally described the problem via: "I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125" diameter, 0.400" length). I clamped the cylinder by the ends (faced-off and therefore parallel) in a fairly substantial drill press vise..." The length of the part, .4", less the hole diameter, .1875", is .2125, so using two vises for this part would clamp only about ..11" of material at each end. It would be better to make a jig to hold the part for cross drilling. The jig would have a horizontal 5/16" hole to hold the part and an intersecting vertical 3/16" hole for cross drilling. If the jig were split vertically and hinged at the bottom, it would clamp the part when clamped in a vise. If the jig were split horizontally and clamped with vertical screws or with C-clamps, a hardened drill guide bushing could be pressed into the top half of the jig, or the jig itself could be hardened. If making only a few parts, don't bother splitting the jig, just drill the intersecting holes and start drilling parts. Once the drill bit enters the side of the part, the part won't shift within the jig. -- jiw |
#31
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Those wretched cross-holes
"DoN. Nichols" wrote in message ... [ ... ] As for "lubricant" -- what are you using? You really don't want to lubricate -- you want to cool (remove heat from the tool and the workpiece), and to chemically aid the peeling of the metal away from the workpiece. Things like Rigid high-sulfur pipe threading oil will work sell for the purpose. Rapid Tap [ ... ] Well ... Both V ways were probably cut on the same machine, so the depth should be the same. A quick check is whether both the horizontal workpiece and the vertical guide (which for test purposes can simply be another cutoff of the same stock) are firmly gripped by the vise at the same time. It probably does not hurt to add paper between the moving jaw and the workpiece and guide to make up for the jaw tilting slightly as it is tightened. I shall look into that. -- Michael Koblic Campbell River, BC |
#32
Posted to rec.crafts.metalworking
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Those wretched cross-holes
"James Waldby" wrote in message . .. OP 21 Sept 2009, Michael Koblic originally described the problem via: "I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125" diameter, 0.400" length). I clamped the cylinder by the ends (faced-off and therefore parallel) in a fairly substantial drill press vise..." The length of the part, .4", less the hole diameter, .1875", is .2125, so using two vises for this part would clamp only about .11" of material at each end. It would be better to make a jig to hold the part for cross drilling. The jig would have a horizontal 5/16" hole to hold the part and an intersecting vertical 3/16" hole for cross drilling. If the jig were split vertically and hinged at the bottom, it would clamp the part when clamped in a vise. If the jig were split horizontally and clamped with vertical screws or with C-clamps, a hardened drill guide bushing could be pressed into the top half of the jig, or the jig itself could be hardened. If making only a few parts, don't bother splitting the jig, just drill the intersecting holes and start drilling parts. Once the drill bit enters the side of the part, the part won't shift within the jig. Others suggested exactly that. I was hoping to get away without having to spend time making a jig as this was a one off part of an experimental design. However, as the procedures are beginning to take shape I see that I shall have to make not just one but several of these if I cannot make Don's method work on my existing vise. -- Michael Koblic Campbell River, BC |
#33
Posted to rec.crafts.metalworking
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Those wretched cross-holes
"DoN. Nichols" wrote in message ... snip Was the workpiece hollow or solid metal? If solid, check whether your drill press vise has a horizontal V-groove, ideally with a Vertical one meeting it in the fixed jaw. These give a good grip, and the vertical V-groove gives access to the area which you want to cross-drill. (For that matter, you can take a short piece of material the same diameter, face off the ends and drill through the center just the size to accept the drill bit which you intend to use, and drop it down the vertical V-groove after inserting the workpiece in the horizontal V-groove. Then Tighten the vise and drill guided by the existing center hole. (If you're going to drill a lot of holes like this, make the guide out of drill rod, and harden it after machining (facing and drilling), so it will last longer. Probably a good idea to use a countersink to chamfer the hole at the upper end at least -- and probably both ends so you don't have to worry about which end is up. Follow-up: I had to make another of these parts in a hurry. No time to make a jig. I looked at all my drill presse vises and *none of them* had a horizontal V-grove matching the vertical one. In fact my favorite vise had *three* vertical grooves, all different, none-matching the horizontal groove. I tried wrapping some tape around the improvised guide but the result was way off center. So back to end clamping. On this occasion however I made sure that the steel was "certified mild" and the drill was a stub drill. It worked like a charm! I shall still look into a jig in the future when the current crop of problems is sorted. BTW, is 12L14 much different from 1018? -- Michael Koblic Campbell River, BC |
#34
Posted to rec.crafts.metalworking
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Those wretched cross-holes
On 2009-10-03, Michael Koblic wrote:
[ ... ] I had to make another of these parts in a hurry. No time to make a jig. I looked at all my drill presse vises and *none of them* had a horizontal V-grove matching the vertical one. In fact my favorite vise had *three* vertical grooves, all different, none-matching the horizontal groove. Ouch! I tried wrapping some tape around the improvised guide but the result was way off center. So back to end clamping. On this occasion however I made sure that the steel was "certified mild" and the drill was a stub drill. It worked like a charm! I shall still look into a jig in the future when the current crop of problems is sorted. BTW, is 12L14 much different from 1018? Yes, very different to machine. (But it is not good to weld, because of the lead in the alloy, which makes it so nice to machine.) Both are probably about equally hard, but when you are cutting metal the difference is amazing -- and it will show up in the finish you get, too. 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 --- |
#35
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Those wretched cross-holes
Michael Koblic wrote:
(...) So back to end clamping. On this occasion however I made sure that the steel was "certified mild" and the drill was a stub drill. It worked like a charm! Good on ya, Michael! Even with 1018, your vise clamping pressure would have had to exceed 1150 lbs in order for it to be the cause of the drill binding. (Seemed unlikely.) --Winston |
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