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Holding morse taper shaft in lathe chuck

renonick

Plastic
Joined
Nov 23, 2021
I'd like some advice on holding a morse taper 2 shaft in a 3-jaw chuck on my lathe. I'm worried that the chuck's jaws might mar the shaft and won't hold the shaft securely.

The goal is to use the lathe to create a hole saw arbor using this McMaster part: McMaster-Carr

Screen Shot 2021-11-23 at 9.06.55 AM.jpg

Thanks!
 

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
Hold it on the straight shank of the 'machinable end.' Otherwise put the correct adapter in the spindle of your lathe and put the MT2 directly in that adapter. If the second option, then you MUST have a center in the end of the part held by the tailstock. Otherwise when you start cutting the outer diameter of the part it will walk out of the spindle.
 

Joe Gwinn

Stainless
Joined
Nov 22, 2009
Location
Boston, MA area
You cannot hold a morse taper in a standard lathe chuck. You need a morse taper socket sleeve with accurate cylindrical outer surface, such as an "Interstate MT2 Inside Morse Taper, Standard Morse Taper to Straight Shank 4" OAL, Medium Carbon Steel, Hardened & Ground Throughout" from MSC. One can get unhardened sleeves as well, allowing machining of the sleeve.

https://www.mscdirect.com/product/details/00185041
 

JST

Diamond
Joined
Jun 16, 2001
Location
St Louis
Even then you may not get it to stay in when machined. Try to keep all the cutting having force "inwards" toward the holder.

That means inserts or HSS that cut on the left side and not on an angle or on a corner radius. Radial forces will try to "walk" the part out of the holder.

If you are going to use it with a drawbar (absolutely recommended), then you can put the drawbar socket feature in first, and then use the drawbar to hold the part in a taper holder. That way there is no concern as the part cannot escape from the holder. You might have to modify a holder to let the drawbar through.
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
It could go into the tailstock and use a hole saw or boring head in the chuck. Any threading will have to be with a die, no single pointing that way.
rotary table on the mill if it has a mt2 center hole.
Bill D
 

renonick

Plastic
Joined
Nov 23, 2021
Thanks for your suggestions everyone! Joe Gwinn found a sleeve that I didn't see on McMaster's site. I can secure the morse taper into the sleeve with a drawbar as JST recommended and secure the sleeve in the 3-jaw. Just what I was looking for!
 

Joe Gwinn

Stainless
Joined
Nov 22, 2009
Location
Boston, MA area
I don't think that that MSC Interstate sleeve has an axial through hole, needed for a drawbar. The sleeve is hardened, so a carbide drill bit would be needed. I suppose that one could glue the workpiece into the sleeve using hot pitch, and later release it with heat and solvent. For a one-off, this would be reasonable.

There are machinable sleeves, but I don't recall who has them.

One can always anneal hardened sleeve in a stainless-steel foil bag with some sacrificial paper, to prevent scale.
 

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
Thanks for your suggestions everyone! Joe Gwinn found a sleeve that I didn't see on McMaster's site. I can secure the morse taper into the sleeve with a drawbar as JST recommended and secure the sleeve in the 3-jaw. Just what I was looking for!

You don't need a drawbar if your machining operation allows a center in the part, pushed on by the tailstock. The issue is that any inward radial cutting force will tend to pop your part out of the headstock.
 

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
Put taper end in 3 or 4j, pushing large shank all the way to the jaws. Support the outer end with a center.

Machine your features, leaving a stub to chuck onto.

Put stub in chuck, part off.

Programmed via Mazatrol
 

crickets

Hot Rolled
Joined
Jul 3, 2021
I assume the lathe in question isn't one of the Chinese ones with MT already in the spindle :D

I'm not sure what the final saw arbor is supposed to look like, but seems like this is a good candidate for turning between centers.
 

dian

Titanium
Joined
Feb 22, 2010
Location
ch
i dont see where the problem is. is you chuck too small for the arbor? then do as cole said (although i didn get the "part off" part). stick the mt2 taper all the way into the chuck, maybe indicate the arbor, support with tail and machine.

i would not use a saw larger than 2" on that mt2 taper, btw.
 

DDoug

Diamond
Joined
Oct 18, 2005
Location
NW Pa
Why not chuck on the large dia. put in a center drill on the end.

Remove from chuck, chuck up on a dead center (machine in place is better yet)
Use live center in tailstock to engage the newly drilled end.
Drive dog on MT end, engages with a jaw for drive.
 








 
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