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Collet for Atlas Clausing ?
- Thread starter minsk
- Start date
- Joined
- Dec 25, 2011
- Messages
- 10,511
There are basically three choices of collets for the Atlas 6", 2MT, the Atlas M6-751, and the smaller ER's.
If all that you need to do is hold milling cutters, the 2MT is probably the least expensive option. AFAIK the 2MT collets only came in 1/16" increments and each size only has a gripping range of about +/- 0.005". For gripping parts, you would be limited to 1/16" increments. So not a good choice for general use.
The M6-751 sold by Atlas is rare in a complete set and is almost certain to be the most expensive option. Plus the largest diameter that is available is 9/32". So I would judge it not a good choice unless your only need for collets was working on parts always under 5/16" diameter and you find the set cheap.
ER32 or ER25 holders or closers are available from several sources, or buy the nut and make the rest. There are three types or styles.
The first and least desirable is mounted on a 2MT arbor either with or without a draw bar. Avoid the one without a drawbar as sooner or later, the arbor will get loose in the taper and probably ruin the part. The arbor with drawbar works OK except that you can't pass long parts or stock through the spindle. And you need to use a spindle thread protector with it. However, it and the 2MT's are the only ones safe for machining with in Reverse.
The second type is mounted on a face plate that screws onto the spindle. The only disadvantage to this one is that it sticks out farther than the others. It is advantageous to a seller as the same chuck or closer can fit a face plate for any lathe.
The third type screws directly onto the spindle and in most cases is the preferred type.
If all that you need to do is hold milling cutters, the 2MT is probably the least expensive option. AFAIK the 2MT collets only came in 1/16" increments and each size only has a gripping range of about +/- 0.005". For gripping parts, you would be limited to 1/16" increments. So not a good choice for general use.
The M6-751 sold by Atlas is rare in a complete set and is almost certain to be the most expensive option. Plus the largest diameter that is available is 9/32". So I would judge it not a good choice unless your only need for collets was working on parts always under 5/16" diameter and you find the set cheap.
ER32 or ER25 holders or closers are available from several sources, or buy the nut and make the rest. There are three types or styles.
The first and least desirable is mounted on a 2MT arbor either with or without a draw bar. Avoid the one without a drawbar as sooner or later, the arbor will get loose in the taper and probably ruin the part. The arbor with drawbar works OK except that you can't pass long parts or stock through the spindle. And you need to use a spindle thread protector with it. However, it and the 2MT's are the only ones safe for machining with in Reverse.
The second type is mounted on a face plate that screws onto the spindle. The only disadvantage to this one is that it sticks out farther than the others. It is advantageous to a seller as the same chuck or closer can fit a face plate for any lathe.
The third type screws directly onto the spindle and in most cases is the preferred type.
Last edited:
- Joined
- Feb 14, 2016
- Messages
- 623
If all you want to do is hold a e'mill get one of these https://www.ebay.com/itm/1-2-MT2-MO...h=item461b0b88ce:g:FLQAAOSwIedbBXkC:rk:4:pf:0
er 32 by the Beall Co . http://www.bealltool.com/products/turning/colletchuck.php
Not optimum but inexpensive , I made my own .
https://www.hobby-machinist.com/threads/draw-bar-and-collets.72617/
er 32 by the Beall Co . http://www.bealltool.com/products/turning/colletchuck.php
Not optimum but inexpensive , I made my own .
https://www.hobby-machinist.com/threads/draw-bar-and-collets.72617/
- Joined
- Mar 22, 2014
- Messages
- 847
There are lots of examples online of people who have made ER collet chucks for their Atlas lathes. Once you have experience making your thread protector you could do a collet chuck. The chuck is basically an extended thread protector with a cup for the collet and external threads for the collet nut. It would be a good learning experience and a very useful addition to your lathe. You would need to purchase the nut and wrench and a few common collet sizes. Then fill in with other sizes as you need them.
- Joined
- Sep 26, 2018
- Messages
- 191
thats a great idea...i bought an internal threading tool i do not have one...now i have to figure out what the internal hole dimension is for the 1"-10 thread. the draw bar that came with the milling attachment i just bought will hold all my 3/8 milling bits...which is pretty nice.
- Joined
- Apr 23, 2014
- Messages
- 40
One thought I just had was to get one of these:
littlemachineshop.com
littlemachineshop.com
And then drill/bore/thread the end to fit the lathe spindle. I am not sure how easy it would be to make sure the threaded hole is concentric with the collet side though.
Collet Block, ER-25 Square 5912
ER Collets & Collet Chucks 5912 Uses standard ER-25 collets; Through hole permits long parts to be machined; Hardened Tool Steel, Ground to .0005" on ...
Collet Block, ER-25 Hexagonal 5911
ER Collets & Collet Chucks 5911 Uses standard ER-25 collets; Through hole permits long parts to be machined; Hardened Tool Steel, Ground to .0005" on ...
And then drill/bore/thread the end to fit the lathe spindle. I am not sure how easy it would be to make sure the threaded hole is concentric with the collet side though.
- Joined
- Dec 27, 2014
- Messages
- 4,056
I purchased on-line an ER40 / MT2 with drawbar for my MK2. Not perfect, but I made a support for it that once the drawbar was set, I screwed (1"-10) my support against the back of the collet. It gave it considerable stability.