Chuck stuck on Lathe

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mu38&Bg#

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So, I bought a Clausing 4902 this summer. I'm just getting around to setting it up and can't for the life of me get the back plate off the nose. I've put WD40 in the threads i've heated the backplate but not too hot, I'm not sure how hot I want to go. I've had a 3 foot breaker bar of the faceplate between the screws. I'm not sure what my options are here.

Greg
 
I've got a friend that swears by Kroil for loosening rusted/stuck parts.

Never used it myself so I can't offer a personal opinion.

Post some pictures of the lathe please. I'd like to have a Clausing 4900 series lathe. ;D
 
I've used Kroil before with no luck, guess it just depends on the situation. If worse comes to worse, you could always turn the face plate off the spindle, being careful to not damage the threads. Take a cut off wheel on a dremel and slice it lengthwise in hopes of splitting the nut. Just like removing the old receiver stubs from demilled rifle barrels.
 
Donning my asbestos suit, let me say that WD40 is as useless in this application as it is in most of the uses to which it is applied.

Kroil is definitely the weapon of choice. Heat the faceplate and apply the Kroil while it is warm. Repeat this process several times over the period of a few days. Bolt a cheater bar to the faceplate. With the spindle locked in place*, apply shock loads and/or vibration to the cheater bar.

Have patience. It took me a week of daily diddling to get the chuck off my lathe after it was delivered.

Also consider putting some dry ice in the spindle bore.

-----------------

* Don't use the backgear to lock the spindle - you risk breaking gear(s). An expanding collet type lock inside the spindle bore is to be preferred.
 
As strange as it sounds. I've had mucho luck with such stuck threads by actually attempting to TIGHTEN it. Just the slightest movement whatsoever would be enough to get the threads unstuck and then loosening is much easier.


Kermit
 
Hi

As Marv says .. VIBRATION ...

A few months ago we had a 3MT/2MT adapter stuck, all manner of methods were tried, all to no avail.

Heat, pipe freezer, diesel, prayer, no joy.

Then we got a SDS drill, put a ground off chisel in it, Roto-Stop, applied to end of offending 3MT bit, and it flew out.

Light touch, fast speed.

May work for you..

Best of luck

Dave
 
Hmm, now to find Kroil. I've never heard of it before. I'll see what I can come up with to add some vibration. I don't have a hammer drill. I didn't want to use a hammer for fear of damaging the spindle bearings.

I'll get some photos of the lathe soon. I need a few things before it's up and running.

Greg
 
dieselpilot said:
Hmm, now to find Kroil. I've never heard of it before. I'll see what I can come up with to add some vibration. I don't have a hammer drill. I didn't want to use a hammer for fear of damaging the spindle bearings.

I'll get some photos of the lathe soon. I need a few things before it's up and running.

Greg
You've got no location listed, but if you're in an area with a lot of rifle shooters, Kroil can often be found at gun stores since it's used in cleaning benchrest rifles.
 
I'm probably going to end up buying PB Blaster. I might have something else sitting around though. I'll have to look.
 
dieselpilot said:
I'm probably going to end up buying PB Blaster. I might have something else sitting around though. I'll have to look.

OK, but get some Kroil for the next time you encounter a stuck or rusted thread. You won't regret it. Consider it an investment in frustration reduction.

It probably won't help much for a faceplate but, for smaller screwed fittings, one of those vibratory engravers (they're cheap - every shop should have one) is a good tool to apply the ever helpful vibration. On nuts, I use the Dremel to grind a small dimple to accept the engraver tip and keep it from "walking" off the nut. Also, Kermit has the right idea. Torquing the nut back and forth (i.e., tighten and loosen) helps the Kroil penetrate and helps break the bonding.

BTW, once you get the faceplate off, get in the habit of oiling the spindle threads before mounting anything. I keep an oil-soaked toothbrush in the chip tray and apply that with the spindle turning in reverse before each mounting.
 
Marv is 100% correct about the usefulness of Kroil. Once you put it on, you need patience, but it will do the job. The best thing is to put it on and walk away and forget about it while. I have also used PB and it isn't as good as Kroil.
Here is a link for another source-http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=7610&title=KROIL
If you have good gunshops in your area, they should have it.
Regards,
Fred
 
There was a good discussion of removing a stuck chuck over on the Home Shop Machinist forum a while ago.

In particular, one responder recommended clamping a longish bar to the left-hand end of the spindle to act as a wrench (make more or less a split bushing at the end of the bar, so it can be clamped together on the spindle with a couple of good-size bolts) and use that to hold or turn the spindle instead of relying on engagement of the backgears to lock the spindle. Then you can really haul on the faceplate without worrying about breaking the backgears.
 
What kind of spindle attachment is it? L00 or threaded?
 
I got the backplate off this morning. I picked up some Corrosion X for my RC engines and while reading the can it said it would loosen stuck parts. So I sprayed some on a few days ago. Today I heated the back plate to maybe 150°F and jumped on a 3 foot breaker bar. I've never seen a breaker bar bend that much (my uncle makes makes them for people like Snap On, Mac, Matco, so I know it won't break), but after a few taps on the back plate it popped.



The Clausing 4902



The Atlas Craftsman 12x36



The Ebay parts mill. I'm working on mounting a minimill milling head to it.

There are plenty of other projects. Please excuse the forking mess. The shop is a disaster right now.

Greg
 

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