Repair of D1-3 spindle taper

[Earl Sigurd]

I have a CVA aka UK version of 10EE. The spindle cone has been molested so that it is undersized and also is no longer a cone. First noticed this when the body of a chuck had visible runout.

The runout measured TIR on the chuck body 0.26mm/ 0.010" The spindle cone shows less than a tenth.

How would you fix this? Hardchrome the cone to oversize and then grind back? Just regrind but the flat face would have to be taken back at least 0.040" assuming the chuck body showed showed the max eccentric TIR. i.e when centred 0.005 clearance either side and with a 1 in 8 taper on the cone.

 

[howieranger]

There is a recent YouTube on regrinding a D spindle that seemed to be very through and well thought out. Search Mr. Chrispin on you tube.

 

[Seaman]

There still looks like a taper in the photo. Have you tried a different chuck or collet nose to confirm they are not the problem? If the spindle nose is still tapered, just relieving the flat will tighten the cone interface. No need to build up the taper. If you remove the three studs and slide the chuck on, can you measure any movement?

 

[guythatbrews]

Building up the spindle is a lot of work and expense. I would just move the profile back. That is assuming there is enough adjustment on the camlock studs. If there is not you can turn the nose down straight and shrink a bushing on it and turn it back to size. If you use the inside spindle taper this might close it up a bit at the mouth but with the nose in that shape the taper may be crummy anyway. If you are unsure of turning rather than grinding give it a try on the shrunk on bushing. If you are not happy then you can grind.

Find the specs on the spindle and measure the nose diameter over pins. This will give you a better idea of how much you need to remove.

There still looks like a taper in the photo. Have you tried a different chuck or collet nose to confirm they are not the problem? If the spindle nose is still tapered, just relieving the flat will tighten the cone interface. No need to build up the taper. If you remove the three studs and slide the chuck on, can you measure any movement?

Checking w/o studs is an easy thing to do. It looks to me like the taper is shot like somebody polished it to death. It's hard to see how they could remove that much by polishing.

 

[rke[pler]

How sure are you that it's the taper on the spindle nose? I'd triple check that with a good quality backplate at the minimum, a gage if you can find one.

As for repair, I think I'd try and find a shop able to spray it. A good crankshaft shop would have that ability and a fair number of job shops have it. That process can lay down a fairly thin machinable surface. It's a hot process and would require spindle removal and some prep to give a rough surface for the spray to adhere.

 

[MCritchley]

I would make a new chuck back plate and invest in a set tru chuck. Any proper tool room lathe should have one.

If you have the wherewithal to pull the spindle and have it ground it would be best to send it to Monarch. They have very special grinder to do the face, OD, and ID taper.

 

[johnoder]

Maybe helpful if you are showing us D1-3".

 

[Earl Sigurd]

It is the taper that is undersized, the Burnerd chuck fits perfectly on my other CVA, when the camlocks are released on that machine you have to give the chuck a slight whack to free it. Unfortunately I don't have access to that machine at present or I could compare both by measuring over pins.

I will check radial play with pins removed later today. Will also see what scanning the taper using DTI on topslide set as best I can to the correct 7-7-30 angle shows up. Well within half a degree anyway. This is to try and see how rounded off the smaller end of the taper is.

 

[AlfaGTA]

Contact Monarch. Might have a used good spindle……
Would be better solution if disassembly was in the cards.
Cheers Ross

 

[john.k]

I fixed a D1-3 spindle with a badly mangled cone seat by simply turning the whole thing into a bolt flange ........as the lathe only had 20" between centres ,eliminating the camlock allowed a couple of more inches of usable bed.

 

[Earl Sigurd]

GTB's
" It looks to me like the taper is shot like somebody polished it to death. It's hard to see how they could remove that much by polishing."

Agree, only had short time to have a look today, as if someone had wrapped some abrasive paper round the cone and stuck the spindle on full speed.

The conical part has a rounded profile in the axial direction, visible with a rule against light.

Will report on further moves.

 

[Overland]

Could you regrind the taper and face in place, using a toolpost grinder.
Using a known good back plate as a gauge, with blue, etc.
Set the compound with a sine bar, etc ?
Minimum off taper to clean up, then off face as required.
Pins should have enough adjustment.
Bob

 

[swatkins]

I have a newer model 10ee that had a messed up nose on it.. someone ground off the taper and then used foil tape to make the chuck tight.. The reason they ground it off was a very bad wreck that bent the shaft .004.... Check the inside taper for run out. They ground the nose and did not touch the taper on mine... A viewer was kind enough to donate a spindle he had laying around to fit to the machine..

 

[Tyrone Shoelaces]

Grind, chrome plate, grind.

Regards Tyrone

 

[rimcanyon]

I have a good used 10EE spindle. Contact me if you are interested. Shipping to UK would not be cheap.

 

[AlfaGTA]

As I suggested some posts earlier a “good” spindle would be an excellent solution.
Biggest issue I see is changing the spindle really would require new spindle bearings.
Don’t think it would be possible to press the bearings off the damaged spindle and fit them to a replacement spindle and not kill the precision of the bearings.
Of course it all hinges on what the owner expects out of this lathe and the work it needs to produce.
Cheers Ross

 

[bsg]

There is a recent YouTube on regrinding a D spindle that seemed to be very through and well thought out. Search Mr. Chrispin on you tube.

Here’s the link to the video, he also shows grinding the backplate as well in another video…….I would try this method first if you have enough material left to grind to bring it into spec?

Kevin