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Collets For a Cummins 7X12 mini-lathe??

Cdrsuppo

Registered User
Jun 5, 2005
18
0
0
I have read many of the posts under 'collets' looking for anything to recommend the type of collets that would be suitable for a Cummins 7X12 min-lathe. The lathe has a Morse Taper 3 in the spindle. I would like a collet that has the ability to pass the bushing rods through it. I have seen sets for MT3 which has a drawbar but it isn't clear on theat feature. There seems to be a multitude of types (3C, 5C, ER32, etc). I would imagine the sizes from 1/64 thru 1/2 inch would be what is required for the typical clock. Any info would be much appreciated. I am for the first time 'in between the plates" of a Seth Thomas mantel clock which at the very least needs arbor bearings. I am getting by with the 3-jaw chuck but collets would be better.
I just registered with this BBS.
Thanks in advance.
 

Cdrsuppo

Registered User
Jun 5, 2005
18
0
0
I have read many of the posts under 'collets' looking for anything to recommend the type of collets that would be suitable for a Cummins 7X12 min-lathe. The lathe has a Morse Taper 3 in the spindle. I would like a collet that has the ability to pass the bushing rods through it. I have seen sets for MT3 which has a drawbar but it isn't clear on theat feature. There seems to be a multitude of types (3C, 5C, ER32, etc). I would imagine the sizes from 1/64 thru 1/2 inch would be what is required for the typical clock. Any info would be much appreciated. I am for the first time 'in between the plates" of a Seth Thomas mantel clock which at the very least needs arbor bearings. I am getting by with the 3-jaw chuck but collets would be better.
I just registered with this BBS.
Thanks in advance.
 
G

Gnomon

Sadly, with a few notable exceptions, collets are unique to the lathe manufacturer. The exceptions were originally designed by one manufacturer, or another, and became defacto standards when they were copied by others (in an attempt to steal business). WW (Webster-Whitcom), and 5C (Hardinge Cataract), came about this way. 3C is a small collet for the Cataract, and 3A is a similar collet for the 10 inch Atlas.

If your spindle is truly a #3 Morse taper, then that is what it fits. You could probably make an adapter to WW, or some other tiny collet.

Good luck,

-Chuck Harris
 

David Robertson

Registered User
Jan 6, 2003
1,525
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Hi..

The MT 3 collets you have seen advertised will have a solid drawbar.. so you will be limited in how deep you can insert stock into the collet.

Threre are some reasonably priced ER sets available that use a jam nut instead of a drawbar and can pass long stock through the center. The holder will need to fit your headstock taper.
 

StephanG

Registered User
Jun 24, 2007
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Australia
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I have a set of ER32 collets and one of the things I like about them is the range each will cover. My set is in 32nds and runs from 2 to 20. Each will close down to meet the one below so with 19 collets you get the full range with no gaps.
For smaller stuff I made an adaptor to take 8mm ww collets.
I have a hollow draw bar for it and it all works fine.
Don't discount the idea of a good quality 3 jaw chuck.
Something like a "Bernard" or a "Grip Tru" can be pretty accurate and has the advantage it can hold stuff other than round.
All depends on what you want to do.
 

AJSBSA

Registered User
Nov 24, 2009
558
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Cheshire, UK
www.ajsbsa.co.uk
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I use a ER16 collet chuck on an adjustable backplate so I can tweek it to acheive less than .01mm runout in seconds I have also done the same for my 3 jaw. I would say a ER32 chuck would be a bit large for clock work but you could fit a ER16 or ER11 chuck in a ER32 one with good effect as you can get them on ground 20mm or 16mm arbors.
 

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