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Samuel
10-03-2005, 04:01 PM
Hi guys,

I am trying to figure out what a good system for holding .25 " drill rod in my atlas 101 lathe would be . I do have a 4 jaw chuck , but frankly its to slow for the project that I am working on. I have used collets on other lathes but they were already set up, so I basicly have no experience. the headstock has an mt2 taper. I dont really want to buy a 3 jaw chuck for this project because my fingers will need to be close to the work piece for the final finishing opperation. any ideas?

thanks

Samuel

C - ROSS
10-03-2005, 04:26 PM
On my old Atlas 10-24 is set up with a quick release 3AT collet attachment, works good for small round stuff. Lots of luck finding collets and other stuff.

Ross

Alistair Hosie
10-03-2005, 04:28 PM
yes the collet system will do this best.Alistair

Joel
10-03-2005, 04:42 PM
Sounds like a job for collets, but for a one-off job, why not make up a fixture? Mount the fixture in the 4 jaw and make it long enough so you aren't uncomfortably close to the jaws. You could use a setscrew to hold the drill rod in place. You could also mount a drill chuck in the headstock or even in the 4 jaw, and use that for a mini scroll chuck.

nheng
10-03-2005, 05:13 PM
Turn a bushing and bore it for the drill rod and slit it (slitting saw, hacksaw, etc.) so it can collapse on the rod. Hold it with the split between two adjacent jaws. Loosen 2 jaws to release the part and grab a new one. It will collapse better if the slit extends beyond the diameter, into the opposite wall of the bore. Den

Samuel
10-03-2005, 05:15 PM
thanks guys, I think that collets are a good idea to, Joel, good thinking I actually used the mt2 drill chuck from my clausing tail stock for the first one but it doest hold stock long enough for the application and is way out of true. so I guess the question is , exactly how do I set up a collet system on a lathe with a mt2 spindle taper? I only need one size collet.

thanks

Samuel

Evan
10-03-2005, 05:34 PM
Make a collet. MT2 tapers 0.04995 per inch. Use mild steel.

Face off the ends of a 5" piece of 3/4" round stock.

Chuck up an existing number two morse taper in the 4 jaw with the small end out. Make sure it is straight! Use this in combination with a dial guage to set the compound at the correct angle to cut the taper, about 1.5 degrees. Lacking a dial guage that is mountable on the tool holder you can use a blunt tool and some shim stock to get the angle right along the length of the taper.

Alternately, you can use a dial guage to measure that the compound is set to an angle that produces a change on a piece of round of 0.025" per inch.


Chuck up the round in the four jaw. Drill and tap the end to take a 5/16" x 18 tpi closer rod. Rechuck it leaving 3" inches extended from the chuck.



Machine on a taper that starts at 0.572" and ends at 0.700" over 2.562". Go past this toward the chuck about 0.25". Take a small cut at a time dialing it in with the cross feed. This will be difficult as the tailstock can't be used to steady the work. You might find for your application an aluminum collet will work.

You may need to do this in two stages depending on the travel of your compound. Polish the taper up with a bit of emery and oil.

Make a closer with a piece of suitable length all thread rod. Mount the new taper in the spindle and thread in the all thread. Thread on a nut that fits inside the spindle to help center the all thread. Put a few suitable washers on the left end and wind on a nut. Tighten it to draw in the taper. Face off the taper to 1/4" from the end of the spindle.

Drill it to just under 1/4" using a drill in the tailstock. Ream it to size with a 1/4" reamer. Lacking a reamer then drill it by the smallest steps available to finish size.

Remove the nut from the all thread and whack the end of the rod with a block of wood or lead to release the taper. Put it in a vice and slot it at least 1.5" twice with a hack saw leaving four equal jaws.

Clean up the slots with a triangular needle file. You now have a handy 1/4" collet.

mochinist
10-03-2005, 07:10 PM
5c collet chuck (http://www.jlindustrial.com/catalog/product.jsp?origin=SEARCH%3AKEYWORD&id=PML-46002K#) http://www.jlindustrial.com/web_graphic/product/p/pm/PML-46004.jpg Would one of these work for you, I have seen these chucked up in 4 jaws when people don't have a collet closer for their lathe. If it would all you would need is a 1/4" 5c collet. If this is a money job I would go this route, if it will work for you. If it is just a home project for yourself, then Evans way would be good experience and save you the cash.

snowman
10-03-2005, 07:18 PM
those things are worthless on a lathe as far as i'm concerned.

i use them all the time on the mill, but part of the ease of using collets in a lathe, is loosening the collet without having to reindicate (in a four jaw at least).

So, you use one of those in a four jaw and you still end up re-adjusting every single time.

-jacob

mochinist
10-03-2005, 07:22 PM
<font face="Verdana, Arial" size="2">Originally posted by snowman:
those things are worthless on a lathe as far as i'm concerned.

i use them all the time on the mill, but part of the ease of using collets in a lathe, is loosening the collet without having to reindicate (in a four jaw at least).

So, you use one of those in a four jaw and you still end up re-adjusting every single time.

-jacob</font>

Hmm I have never used them, only seen them being used, and the guy wasn't taking it out of the 4 jaw each time. It was a pretty good sized 4 jaw though maybe it had more room to move the handle, I don't know. It was worth a try though.

Steve Stube
10-03-2005, 07:49 PM
Atlas (Clausing) can probably sell you the collet and collet closer you need for your lathe. If a thru hole is not needed for feeding the 1/4" rod thru the headstock you can probably get by with one of these $40.00 MT# 2 3 jaw chucks.
http://cgi.ebay.com/Craftsman-Atlas-Dunlop-Mini-101-Lathe-3-Jaw-Chuck-MT2_W0QQitemZ7551240128QQcategoryZ633QQrdZ1QQcmdZV iewItem

Joel
10-03-2005, 11:33 PM
If your drill chuck is less concentric than a 3 jaw lathe chuck, its time to get a new drill chuck!

“How do I set up a collet system on a lathe with a mt2 spindle taper?”
By buying a collet chuck. Cheapest I have seen new is about $150.

I suppose you could take a drill chuck and drill a through hole larger than .250 so stock will pass through it. Just chuck up the body in the 4 jaw.

Would a mt2 end mill holder work?
You could make something similar by taking a mt2 to jt33 adapter (cost $5) and drill the .250 hole in the end. Could be clamped in with a screw, or split and use maybe a hose clamp, or more securely, a nut. To clamp with the nut you would have to taper the threads a bit. There are other ways to be sure.

ulav8r
10-04-2005, 08:40 AM
Travers tool online, browse catalag, page 557 has morse taper collets in 1/4.

darryl
10-04-2005, 08:02 PM
Routers typically have a 1/4 inch collet system. You could cannibalize a defunct router and mate the business end of the shaft to an mt2 arbor. If you bore the arbor for a press fit of the shaft, you will keep the accuracy and will have a collet closer already made, hardened, etc. Without the 1/4 inch collet in place you can drill through the length of the shaft and the arbor up to the point where the allthread rod comes to hold the arbor into the spindle. If you want that hole all the way through, you'll have to arrange to hold the mt2 arbor in place from the nose of the spindle. If it's threaded, that's another little project for you, making a collar to fit those threads to hold the arbor into the spindle.

If you do this combined project, you'll have a dedicated 1/4 inch chuck that will always run true when mounted, as long as you take care of the tapers.

Expanding on this idea, some routers have a 1/2 inch collet system, and you can buy collets to fit it for 1/4 inch shafts. This would be a little more versatile, and the shaft size being larger it will be stronger as well. You can end up with a larger diameter through hole, so you'll have to consider what support the drill rod might need within the spindle.

How much drill rod is going to be sticking out from the holder, and what are the forces going to be on it? You may actually need the rigidity offered by the four jaw chuck, and it's possible you won't get it with the arbor and collet method that I've outlined.

Samuel
10-06-2005, 12:24 PM
thanks for the reply guys, I am going to the " metal store" this week so I will let you know how things turn out.

Spin Doctor
10-06-2005, 02:34 PM
Another thing to think about is how long is the piece of drill rod. If you are going to put the whole stick in and then machine something the ass end will start to whip and pretty soon be bent 90D at the back of the spindle unless it is supported. Pretty dangerous

Samuel
10-06-2005, 04:08 PM
thanks for the warning I will be using 1\2 or 1/3 lengths.

Samuel

Buckshot
10-07-2005, 12:21 AM
........If you're holding short pieces you can get 2MT collets with a 3/8-16 drawbar threading. From 1/8" to 1/2" x 1/16". I got a set off and E-bay auction for about $40. They've gone for more, and I forgot about a set I was watching that went for $29. I've seen adds in the HSM mag from some outfit at $99 for the set.

Rick