removing chuck insert from vicmarc chuck

[doug3030]

Hi guys and girls

I have a vicmarc 120 chuck with an insert for a jet midi lathe. I recently acquired a new lathe - carbatec mc1100. well it would be too much to hope for that the same insert would fit, wouldnt it! Of course it doesnt. now I know I can get a suitable insert to fit the new lathe but the problem is I cant get the old insert out of the chuck!

this is not the current style insert with the grub screw that I have found out about while researching this, no grub screw so it must just be so tight from use that it wont come off. I have sprayed it with CRC for a week and still no difference, my 26yr old brickies labourer son with muscles in his crap cant move it but it was fairly easy to remove the whole unit from the spindle of the jet lathe, where it was subjected to the same forces.

Anyone got any clues, can provide insight or help in any way? I want to get the second insert so that I can use the chuck on both lathes and swap between them fairly easily.

Thanks

Doug

[dai sensei]

I know I used CA on my old one to stop it unturning. Perhaps yours is the same :?. If so, try a quick sharp tap, whilst trying to unturn to break the joint.

[Jim Carroll]

Wow a VM120 on a jet mini lathe, poor thing must have had a heart attack everytime you went to start it.

One way to get the insert out is to clamp the insert in the jaws of your vice and get a flat bar that can go across the jaws. Tighten the jaws onto the bar and turn.

As neil says the insert is jammed tight so you may have to hit the bar to break that seal.

Make sure you have everything closed properly so you do not damage the jaws.

If that does not work clamp the chuck body in the vice and use large multi grips on the insert.

[Tim the Timber Turner]

Put a steel bar in your vice with about 15mm above the top of the vice.

Place the chuck face down onto this bar.

It's best to have the largest diameter jaws available fitted to the chuck.

Tighten the chuck jaws so they lock the chuck onto the steel bar.

This will hold the chuck firmly while you attack the insert with what ever you have available.

I have used a large pipe wrench to apply pressure and then shock loaded directly onto the insert with a hammer, still applying pressure with the pipe wrench.

If this fails then the chuck is useless and you should send it to me.:)
Let's know how you get on.

Cheers

Tim:U

[doug3030]

Dai Sensai, there have been no glues applied but it still may need a sharp tap to free it, at least sharper than we have already tried.

Jim it is a jet midi lathe (not mini) and yes even so it is probably a bit big, i agree, but it was bought for a small job with the next bigger lathe already in mind.

Tim, in the unlikely event the chuck turns out to be useless I will keep your generous offer in mind, but please don't hold your breath. :rolleyes:

Thanks to all for their ideas. I will persist along those lines.

Doug

[Paul39]

Put a steel bar in your vice with about 15mm above the top of the vice.

Place the chuck face down onto this bar.

It's best to have the largest diameter jaws available fitted to the chuck.

Tighten the chuck jaws so they lock the chuck onto the steel bar.

This will hold the chuck firmly while you attack the insert with what ever you have available.

I have used a large pipe wrench to apply pressure and then shock loaded directly onto the insert with a hammer, still applying pressure with the pipe wrench.

If this fails then the chuck is useless and you should send it to me.:)
Let's know how you get on.

Cheers

Tim:U

In addition to the above, squirt your favorite penetrating oil (WD-40, Liquid Wrench, PB Blaster - my favorite) liberally around the interface of the adapter and chuck, let soak overnight. Next day more penetrating oil, heat the chuck body with a hair dryer or heat gun. Then proceed with the hitting.

A hard shock like a Karate chop is better for breaking things loose than a heaver slower hit.

Make a mark on the adapter and chuck so you can see if it moved. After 2 - 3 whacks and it hasn't moved more oil, more soak, more heat. If it moves the slightest bit, it will come off.

Sometimes placing the chuck face down and liberally applying penetrating oil at the interface, then tap, tap, tap, around and around the adapter with a 6 - 8 oz brass hammer will jar the mating surface and let oil into the threads.

Be patient, keep tapping, heating and shocking. Almost always they will come apart.

After getting it apart, clean the threads on the mating surfaces and lightly oil. If there is roughness or rust on either or both threads, use penetrating oil and run the adapter in and out, more oil, in and out, continue until the parts thread smoothly, then clean and oil.

Use what is at hand, motor oil, electric motor oil, sewing machine oil, 3 in 1 oil.

When you go from one adapter to the other always clean and oil the threads.

If a thread locker, Locktite, or CA has been used it will take heat to get it off. Too hot to touch using the hair dryer or heat gun should do it.

[doug3030]

I wish I had done it this way from the start. Instead of trying to improvise, I made a tool specifically designed to do the job - a new set of jaws for superjaws.

50mm angle iron cut to length to be drilled and screwed onto the superjaws and another hole drilled and tapped to take an 8mm grub screw in the middle of the faces at the right height to engage the holes in the insert. once clamped in, that insert was going nowhere and the chuck was facing straight up ready to clamp a lever into the jaws.

I located a suitable piece of hardwood of indeterminate species about a metre long and clamped the centre of it in the jaws so that I could apply even pressure to both ends. So with my feet on the footplates of the superjaws I slowly applied pressure, allowing the timber to flex and build up some torque and just like that it turned.

Up until I made the jaws I had no way of holding the insert still while enough torque was applied to break the seal. the insert would turn in whatever it was being held in before it started unscrewing from the chuck.

So now that I have invested 15 minutes and probably less than $1.00 worth of materials in designing and building a purpose-designed tool this will never be a difficult task again, and to think I probably wasted 3 hours and caused superficial cosmetic damage to the insert trying to do this the hard way.

Anyway, thanks to all who offered advice.

Doug

[doug3030]

If this fails then the chuck is useless and you should send it to me.:)
Let's know how you get on.

Cheers

Tim:U

So I guess you dont get the chuck after all Tim, and I guess this means that I have to keep the three after market jaws sets I would have had to send to you with the chuck if the insert didnt come out. sometimes its just not your lucky day.

[Tim the Timber Turner]

Good thinking on your part Doug.

A great soluution. Well done.:2tsup:

I'm a little disappointed because I already had a spot on the wall picked out to hang your chuck up along with my other Vicmarcs.:~

Cheers

Tim:)

[doug3030]

I made a tool specifically designed to do the job - a new set of jaws for superjaws...

...So now that I have invested 15 minutes and probably less than $1.00 worth of materials in designing and building a purpose-designed tool this will never be a difficult task again...

Doug

And come to think of it, since others have seen the need to glue the inserts into their chucks to stop them loosening while in use, it is probably worth using this setup to put the new insert in when I get it so it goes back on nice and tight too. :2tsup:

Doug

[Jim Carroll]

And come to think of it, since others have seen the need to glue the inserts into their chucks to stop them loosening while in use, it is probably worth using this setup to put the new insert in when I get it so it goes back on nice and tight too. :2tsup:

Doug
There is usually no need for any glue etc for holding the insert in place.

Some of the problems come about because the person has not put the insert in properly and when the lathe starts up with a bowl blank in place the inertia jams the insert into the back of the chuck so overtightening.
The other issue is those that use reverse and dont have the correct insert in place or use the locking screw then they can come undone.