Home |
Search |
Today's Posts |
|
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. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
|
#1
|
|||
|
|||
What lathe to buy?
I need to build an automatic machine to perform a fairly simple job.
I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! |
#2
|
|||
|
|||
In article , Fred wrote:
I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! You don't have to have a collet, you can just grind out a 3-jaw chuck to a good fit on 1.25" stock anmd you are only limited by the spindle hole. Since you are making short pieces you might look at some 3-in-one imports; you don't need the mill part but the rest might be the right size for what you want. -- Free men own guns, slaves don't www.geocities.com/CapitolHill/5357/ |
#3
|
|||
|
|||
Nick Hull wrote: You don't have to have a collet, you can just grind out a 3-jaw chuck to a good fit on 1.25" stock anmd you are only limited by the spindle hole. Since you are making short pieces you might look at some 3-in-one imports; you don't need the mill part but the rest might be the right size for what you want. Well I'm trying to build an automatic machine. With a collet setup using air power to open an close the collet is straight forward. If there are small air powered chucks available I'd like to hear about them. |
#4
|
|||
|
|||
Well I'm trying to build an automatic machine. With a collet setup using air power to open an close the collet is straight forward. If there are small air powered chucks available I'd like to hear about them. I don't understand the concept First one useful thought. Old NC lathes are worthless, and might have a huge spindle bore, if you have floorspace. Why are you starting with 12 inch pieces? What are the accuracy requirements? Are you turning the OD? Give us some idea of the whole concept, perhaps we can be of more assistance |
#5
|
|||
|
|||
On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote:
12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. Seems to me that starting with a lathe would be overkill in this application. A powered drill, a cutoff saw, a collet style clamp would work nicely for the "machining" part and the plastic would not then need to rotate. -- The instructions said to use Windows 98 or better, so I installed RedHat. |
#6
|
|||
|
|||
On Sat, 15 Jan 2005 16:45:20 -0600, Jim Levie
wrote: On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. Seems to me that starting with a lathe would be overkill in this application. A powered drill, a cutoff saw, a collet style clamp would work nicely for the "machining" part and the plastic would not then need to rotate. I just pulled a Zaggar power feed drilling head, along with the Emerson VFD to operate it. Ill make you a very good deal on it. Can be mounted horizontally (usually is) and set up as a fixtured drill unit. Gunner "At the core of liberalism is the spoiled child - miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosphy of sniveling brats." -- P.J. O'Rourke |
#7
|
|||
|
|||
You can forget the small lathes. The spindles won't pass 1.250 stock. Nor
will 2J collets hold that size either. You need at least a D1-4 spindle so a chinese 13 by 40 lathe is what you are looking for and I suggest a 6 jaw chuck. Steve "Fred" wrote in message ... I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! |
#8
|
|||
|
|||
Fred wrote:
12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. Part off first with a "MAKITA 12 INCH METAL CUTTING SAW LC1230" Then face and drill with the 2" long workpiece in practically any 3-jaw chuck in practically any lathe. --Winston |
#9
|
|||
|
|||
In article ,
Winston wrote: Fred wrote: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. Part off first with a "MAKITA 12 INCH METAL CUTTING SAW LC1230" Then face and drill with the 2" long workpiece in practically any 3-jaw chuck in practically any lathe. And by using soft jaws, you can set the chuck up to provide a depth stop as well, to allow facing to a precise and repeatable length if necessary. Or -- since you mentioned the desire for a power-operated collet, I'm holding New England Brass and Tool's new catalog of Bison chucks, and they have a 16C collet chuck as a variant on their 5C collet chuck. Both mount the collet entirely outside the lathe spindle, and the 16C collets in that chuck are spec'd to handle sizes from 1/16" to 1-5/8" -- which should be big enough to handle what you need, since without the drawtube in the spindle, you can clear at least 1-3/8" in any lathe made for 5C collets. It says that it is power actuated, but I don't see how, precisely. I would suggest that you call them (or some other Bison importer) and ask for details. Their phone number is: 781 729 7672 (if I managed to type that correctly around the cat. :-) 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 --- |
#10
|
|||
|
|||
We make a Delrin ( plastic) 1-1/4" roller with OD grove, hole on the centerline
and chamfers on our CNC lathe in about 1 minute. Maybe it would be more economical to buy them from us and forget making a custom machine. We also have a fairly good source for surplus 1-1/4" Delrin. Leigh at MarMachine |
#11
|
|||
|
|||
On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote:
Greetings Fred, An old CNC lathe would be ideal for this job. First though, I wonder why the plastic is in 12" sections. Did you maen perhaps 12 FOOT lengths? Anyway, a CNC lathe would have a turret. You can use the turret index command to open and close a collet if the lathe doesn't already have an automatic chuck. And a bar feed can be made with a rotary union. I would be happy to discuss this with you over the phone. E-mail me and I'll sen you my number. I have modified old CNC lathes for completely autonomous operation. Only loading in new stock is required. Cheers, Eric R Snow, E T Precision Machine I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! |
#12
|
|||
|
|||
On Sat, 15 Jan 2005 16:41:19 -0800, Eric R Snow
wrote: On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote: Greetings Fred, An old CNC lathe would be ideal for this job. First though, I wonder why the plastic is in 12" sections. Did you maen perhaps 12 FOOT lengths? Anyway, a CNC lathe would have a turret. You can use the turret index command to open and close a collet if the lathe doesn't already have an automatic chuck. And a bar feed can be made with a rotary union. I would be happy to discuss this with you over the phone. E-mail me and I'll sen you my number. I have modified old CNC lathes for completely autonomous operation. Only loading in new stock is required. Cheers, Eric R Snow, E T Precision Machine If Eric doesnt have a machine for you, Im sure I can. Btw..you want 16C collets. I can build you one or find you a suitable old CNC lathe. All it takes are pictures of dead presidents. Gunner "At the core of liberalism is the spoiled child - miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosphy of sniveling brats." -- P.J. O'Rourke |
#13
|
|||
|
|||
"Fred" wrote in message ... I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! Burnerd makes (made?) a collet chuck that will take up to 1-3/8" round stock and each collet has a range of 1/8". There were at least two styles of chuck, one that takes a (large) drill chuck-type key and another with a lever arm that lets one open/close the chuck while it is spinning. The latter might work for your application with some innovative engineering. You can see an example of the collets he http://www1.mscdirect.com/CGI/NNPDFF...PARTPG=NNLMK32 I happen to have one of the lever types for an L-00 spindle with a full collet set that is gathering dust. Email me if you think you might be interested in it. Mike |
#14
|
|||
|
|||
Fred wrote: I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! you need a turret lathe with bar feed if you are just doing that part. JOhn |
#15
|
|||
|
|||
Don't [try to] reinvent the wheel.
What you are describing is a screw machine [or automatic lather for our European friends]. With feed tubes, these can take 8 foot or longer stock eliminating much of the material handling. Brown & Sharpe and Traub are two names that come to mind for what you are doing. Given the description of the job, most likely you can get by using existing "pick-up" cams for minimal tooling costs. Before investing in a machine and the upkeep, I would check to see if there are any screw machine shops in your area and ask them to bid on the job. I am cross posting this to alt.machines.cnc as many people in that newsgroup are also very knowledgeable about screw machines and in many cases have or work in shops with both cnc machines for the short-run high precision jobs and the traditional screw machines for the high volume commodity jobs. GmcD ======================================== On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote: I need to build an automatic machine to perform a fairly simple job. I'd like to use a small lathe, possibly a SB heavy 10, as the basis for the machine as they are fairly easy to find and inexpensive. This will be a dedicated machine that won't be used for anything else, thus it doesn't need screw cutting capability or power feeds. However, I've run into one problem right away that has me scratching my head for a solution. The job: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. The problem: With smaller diameter stock, say 1", I would feed the stock through the lathe spindle, holding it with a collet. Drill 2" in using the tail stock and then part the 2" drilled section off. Feed the bar over 2" and repeat. The problem is 1.25" stock won't fit in a 5C collet, it needs something larger (2J?). What small lathes out there have larger spindle capacity? Most of the lathes set for 5C collets have 1-3/8" spindles, or possibly 1-1/2" spindles, neither of which will accept larger collets. I guess with a 1.5" spindle bore I could fabricate a custom collet that would hold the 1.25" stock, but I don't know if this is the best (only?) way to go. Opinions and ideas on how to approach this would be appreciated. Thanks! |
#16
|
|||
|
|||
On Mon, 17 Jan 2005 12:34:23 -0600, F. George McDuffee
wrote: 12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. Can you get it extruded or cast with the hole (and within tolerance)? What wall thickness? What about molding them? Might be cheaper .... how many per year? What plastic? -- Cliff |
#17
|
|||
|
|||
| On Sat, 15 Jan 2005 17:12:26 -0500, Fred wrote:
| | | The job: | | | | 12" long x 1.25" diameter bars of a plastic material need to be cut | | into 2" long sections withe a hole center drilled their entire | | length. Did you mean 12 _inch_ long bars, or 12 _foot_ bars? What kind of plastic material? What kind of tolerances? What kind of surface finishes (prettiness)? What kind of price range are we looking at? moT |
#18
|
|||
|
|||
In article , Fred says...
12" long x 1.25" diameter bars of a plastic material need to be cut into 2" long sections withe a hole center drilled their entire length. I used to do exactly this. I worked for a company that made nylon sheaves, and rollers. The fastest way is to bandsaw slugs out of your bar stock. Put the slugs in a chuck and finish one side, flip over, finish the other, and bore the center. You will need an operator to do this, but with foot long barstock, a bar feeder is pretty useless anyway. A bandsaw can cut the stock much faster and more efficiently than a parting-off operation in a lathe. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
FS: Sheldon WWII Army lathe and extras | Metalworking | |||
New Mini Lathe | Woodturning | |||
Kelton Balancer Review Draft--long | Woodturning | |||
A Video for Beginners (a bit long) | Woodturning | |||
My $20 lathe (well, sort of...) | Woodworking |