# G0752 Chuck stuck good and hard!



## Perplexed (Aug 7, 2021)

Hi all, this will be my first post since I joined, though I’ve frequented the site over the past few years.  I could always find the info I needed, but not this time, so maybe you folks can help…

I have a G0752Z lathe, and it came from the factory with the 3-jaw chuck installed.   I’ve been using this chuck from the beginning, and it’s now about two years later that I decided to try the 4-jaw chuck.  This is where I ran into a major problem.

Simply put, the 3-jaw chuck is stuck.  As in, will not budge an iota.  I removed the safety collars per the instructions, and inserted the two chuck keys, and tried to spin the chuck off in a counter-clockwise direction.   Nothing. Nada.  So I sprayed some penetrating oil in the seam between the chuck and the spindle collar, and let it sit overnight.  No luck.  I found a length of drill rod blank that just fit into the hole on the spindle collar (where the small chuck key would go) and I put a thick layer of leather on the ways, then braced the drill rod blank against it so I could try again with more leverage.   Nothing.  I even tapped the large chuck key with a soft-headed mallet, with no success.

Before screwing up anything, I contacted Grizzly tech support.  Their answer was basically what’s been posted on YouTube - use a strap wrench on the pulley on the left while using a large adjustable wrench on one of the jaws in the chuck.   That didn’t work since the strap on the wrench kept slipping under force, so I put a layer of sandpaper underneath for added traction.  That still didn’t work.

What I think I’ll need to do is immobilize the spindle completely so I can really wrench down on the chuck with both hands.  Aside of taking all the pulleys, gears, spacers, keys, etc. off the spindle so I can remove the spindle with the chuck still attached, and put the spindle in a padded vise - is there anything else I can try to get the chuck off the spindle??

Thanks in advance!


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## fitterman1 (Aug 7, 2021)

Try removing the jaws and spray some penetrant at the thread seam inside the chuck.
Spray it every half hour for a 2-3 hours.
Try undoing the chuck using a strap wrench on the chuck od, and a long pin punch in the hole behind the register.
If it still doesn't come loose, fit a tommy bar in where the chuck key goes and give it a sharp rap with a decent hammer a number of times.
Protect your ways.
Clean and grease or oil the spindle threads as part of your maintenance.
Let us know how you go.


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## markba633csi (Aug 7, 2021)

You may need to use some heat from a propane torch around the chuck/ spindle interface.  Be aggressive but cautious with the heat. Protect the paint.
A high wattage light bulb put close to the chuck might even be a better choice,  and safer.
Soak with penetrating solvent (liquid wrench) for several days beforehand.  Maybe even a week.  Be patient, it will come off.

Use the strap wrench, perhaps with an additional thick piece of rubber around the pulley to prevent damage. One approach I have used is to put a large hose clamp around the part with a leather belt as a protector.  Then you can grab the clamp with large pliers or strap wrench, wedged against the adjustment screw on the clamp.
Put a long piece of hardwood in the chuck jaws and whack it with a piece of 2x4.  Protect the ways.
Grizzly is good about spare parts if you do mangle the pulley, it just may take time to get one.
-Mark


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## Bob Korves (Aug 7, 2021)

Perplexed said:


> Hi all, this will be my first post since I joined, though I’ve frequented the site over the past few years.  I could always find the info I needed, but not this time, so maybe you folks can help…
> 
> I have a G0752Z lathe, and it came from the factory with the 3-jaw chuck installed.   I’ve been using this chuck from the beginning, and it’s now about two years later that I decided to try the 4-jaw chuck.  This is where I ran into a major problem.
> 
> ...


OK, I gather that your lathe has a screw on spindle.  I would try putting a large Crescent wrench snug on one of the chuck jaws and then use a hammer to jar it loose.  Have something substantial clamped solidly in the jaws.  Have the spindle disengaged from the drive gears to keep them from being damaged.  Don't whack it too hard or you might damage the chuck.  Multiple smaller whacks are safer and usually eventually work it loose with some patience...  A restraint made of belting or a v-belt wrapped around the spindle can help to keep the spindle mostly stationary.


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## SLK001 (Aug 7, 2021)

1) Lock your spindle.
2) Mount some kind of steel bar in the jaws horizontally (you won't operate your lathe).  
3) With the bar sticking out, hang weights from the bar - as much as it will hold.  
4) Walk away (however, protect the ways from a bar coming down).  

Overnight, your chuck should break loose.


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## rabler (Aug 7, 2021)

This is a common problem with the G752Z.  They include screwdrivers,  a little oil bottle and cheap metric wrenches,  but not the spanner needed to loosen the chuck.  I ended up making a custom wrench from some A36 with a pressed in tool steel pin.    You can make something like this using a metal bandsaw, a drill press, and some hand filing.  I used a mill and a rotary table to get the inside curvature exact, but that's not really necessary.    You'll use it over and over, so might as well do it now.  The pin needs to sit at 90 degrees, or a tad more, from the handle.


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## SLK001 (Aug 7, 2021)

I take it that the spindle is _*NOT *_threaded?


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## fitterman1 (Aug 7, 2021)

It is, same as the G0602 model.


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## fitterman1 (Aug 7, 2021)

I used to have a lot of trouble getting mine off too when I first got my lathe. Simply because the thread was poorly machined. I eventually took my spindle out and remachined it so it was actually concentric and of a full form.
 Its size was actually reduced by around 030 thou, but chucks fit on much better and come off easier now.
May pay to check that spindle thread for size and geometric error.


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## RJSakowski (Aug 7, 2021)

I have a G0602 which is same hardware.  I tend to tighten my chuck securely.  I made a pin spanner rather than using a tommy bar.  A 5/8" or 17mm open end wrench on the chuck jaw with the spanner on the spindle will break the chuck free.








						Just One More
					

The Grizzly G0602 has three radial holes in the spindle for the purpose of securing the spindle when installing or removing a chuck.According to the user manual, you are supposed to use the second chuck key as a tommy bar with those holes.  Well the chuck key didn't fit but no problem, I made a...




					www.hobby-machinist.com


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## jpackard56 (Aug 8, 2021)

SLK001 said:


> 1) Lock your spindle.
> 2) Mount some kind of steel bar in the jaws horizontally (you won't operate your lathe).
> 3) With the bar sticking out, hang weights from the bar - as much as it will hold.
> 4) Walk away (however, protect the ways from a bar coming down).
> ...


I've used this method on a hundred year old Seneca Falls and it worked within a couple hours of setting it up.
I did have a goodly amount of PB Blaster on the spindle thread area from previous attempts.


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## SLK001 (Aug 8, 2021)

People are surprised on the amount of torque that it applies.  Fifty pounds on the end of a 3 foot bar gives a moment arm of 150 ft-lbs - a 4 foot bar gives 200 ft-lbs.  And this method doesn't impart any shock to the lathe.


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## Perplexed (Aug 10, 2021)

Thanks for the comments, folks.  I left the spindle swimming in penetrating oil for several days, then I went back out and tried the suggested methods of removing the chuck.

Alas, it is stuck. As in, *stuck*. I really can’t get it loose with one hand on the spindle and one hand on the chuck - I need to have the spindle locked good and solid so I can work on the chuck with both hands. Unfortunately, this lathe does not have a spindle lock, but thanks for suggesting that. Also, I don’t have a machine shop - this lathe is the only such machine I have, as I’m set up almost wholly for woodworking, so I can’t readily fabricate metal tools. Otherwise I’d make an adjustable wrench with three nubs that could clamp down completely around the spindle.  That would immobile the spindle but good!

As it is, I’m resigned to taking apart the spindle assembly so I can remove the spindle and chuck from the lathe.  Then I can put the spindle in a padded vise and have both hands free for the chuck.   I have an exploded diagram of the spindle assembly, but I would appreciate any tips on the disassembly and re-assembly process.  I understand there‘s a potential issue with reinstalling the bearings, and there’s a key on a shaft somewhere?  I can just picture myself cussing as I hear an unseen something fall off inside the housing…


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## SLK001 (Aug 10, 2021)

Perplexed said:


> As it is, I’m resigned to taking apart the spindle assembly so I can remove the spindle and chuck from the lathe.  Then I can put the spindle in a padded vise and have both hands free for the chuck.   I have an exploded diagram of the spindle assembly, but I would appreciate any tips on the disassembly and re-assembly process.  I understand there‘s a potential issue with reinstalling the bearings, and there’s a key on a shaft somewhere?  I can just picture myself cussing as I hear an unseen something fall off inside the housing…



Don't resort to dismantling anything just yet.  Open the gearbox and stick something like nylon, or some other hard plastic into the gearing so that the spindle can't move forward.  Once your spindle is immobilized, you can try the "weight on a stick" approach.  Removing the spindle would be the LAST thing that I would do (okay, second from the last - the last thing I would do would be to turn the chuck mount off the spindle).


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## fitterman1 (Aug 10, 2021)

As already mentioned, don't dismantle anything yet.
Can you unbolt the chuck from the backing plate? Cut these bolts off if you have to. If you can separate them, you can heat the backing plate up and thermocycle it to break the bond holding it to the spindle.


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## fitterman1 (Aug 10, 2021)

And dont jam anything in the gears unless you really want damage.


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## RJSakowski (Aug 10, 2021)

This lathe doesn't have a gear box.  furthermore, the external gears driving the change gears are nylon so I would strongly advise trying to gain leverage by jamming the gears. It's not even a good idea with steel or cast iron gears.

You will not be able to break the chuck loose by use of your hands.  I measured the torque required to break the chuck loose on my 602 at 35 lb-ft.  Once it is broken free, then you can spin it off by hand.


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## DAT510 (Aug 10, 2021)

For my Jet 1024, which also has a screw on chuck,  I've used the method described by Grizzly for the G9249 (Grizzly's version).  It involves mounting a bar in the chuck perpendicular to the face and hitting it with a dead blow hammer.  As unnerving as appears, any impact would be tangent to the spindle bearing, and I've never needed to hit very hard.


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## rabler (Aug 10, 2021)

Since you don’t have the equipment to make one, just buy an appropriate pin spanner wrench. https://www.mcmaster.com/wrenches/wrench-style~spanner/pin-spanner-wrenches-for-holes-on-the-side-7/


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## ericc (Aug 11, 2021)

Is it possible to make a split clamp wrench out of some beefy aluminum plate and clamp around where the pulleys are?  You can put quite a bit of force on it with such a wrench, and you can make it with the lathe, as long as the stuck chuck can hold the plate.


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## KevinM (Aug 11, 2021)

I had a stuck chuck and tried all of the brute force methods.  This method worked well for me.  
See post #19.





__





						Proper way to remove a chuck from a threaded spindle -  		 		The Home Shop Machinist & Machinist's Workshop Magazine's BBS
					





					bbs.homeshopmachinist.net


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## Weldingrod1 (Aug 12, 2021)

Make an expanding plug for the back of the spindle so you can positively anchor it!

+1 on making something to really grab the chuck!

Once you have both of the above, make sure your back stop is solid, and whack your chuck tool. It might work...

Then stick some dry ice in the spindle hole; use rags to locate it. Alternatively, regular ice could work, but it will drool ;-)

Nuke the outside of the threaded area of the chuck, ideally while rolling back and forth; make a heat shield to control heat/paint damage. A torch is really the right tool. You are NOT shooting for glowing!!! Just well above boiling water.

Make sure your back stop is solid, and whack your chuck tool.

If it doesnt let go, apply penetrating oil and come back tomorrow.


Sent from my SM-G892A using Tapatalk


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## Perplexed (Sep 14, 2021)

Thanks for the advice, folks.  I tried the “weight on a stick” method with a 3‘ breaker bar and approximately 50 lbs of weight, and I left it that way for about two weeks (had woodworking projects to keep me busy).   No dice, the chuck didn’t move at all.  I considered the method in Post #19 of that other thread, but the gearing on my lathe doesn’t allow for free-wheeling of the chuck.  I can turn it by hand, but the gears impart a light braking action.  The chuck can’t just spin so there’s not much inertia accumulating in between each of the jaws, if that makes sense.  I wonder though if it’s possible to remove the one gear on the spindle inside the gearbox so the chuck can spin freely.  I’ll have to look into that.

Much appreciated!


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## Bi11Hudson (Sep 14, 2021)

'Way back in the dark ages when I was just starting with _industrial _electrical work, I ran a lot of rigid conduit. I mean a *LOT*, as I was one of the younger guys in the shop and could contort to fit the old(ca1896) mill building. Mostly 3/4 inch rigid which equates to 3/4 inch schedule 40 galvanized water pipe. I got so strong in my hands I could assemble a conduit run by hand that needed a pipe wrench to undo. That was a long time ago, but the memories are still there.

*Which brings me to the problem at hand*. There were instances of 3/4 rigid laid directly on a concrete floor where it could be run over by forklifts and the like. A trick I soon learned was to attempt to *tighten* the joint before loosening it.. Not much, just enough to get it to "creak" or squeel once. On old galvanized pipe, fasteners, most any super tight connection, it did help. Even the longest pipe wrenches would find things easier. It was an old school millwright that showed me the trick. 

I don't say it will solve your problem, but it would be worth a shot. If it didn't work, you only wasted a couple of minutes.

.


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## DAT510 (Sep 14, 2021)

In addition to Bill's idea above....

You might consider using "Impact" vs "Constant" Torque.  I learned early on, working for a shop that restored and maintained very expensive vintage cars, the fastest way to break wheel studs or other bolts was to apply more and greater constant torque.

Impact wrenches work on the principle of "Impulse", High Energy (the impact) for a short duration.  That shock allows the wheel nut or bolt to turn while keeping the stud/bolt within it's elastic range. The pause in between impacts allows the stud or bolt to spring back from it's elastic limit before the next impact.  This is what keeps impact wrenches from breaking things, when grabbing a breaker bar and or cheater bar and just applying more and greater constant force (torque) would.

If you can lock the spindle, you might want to try this method of placing bar perpendicular to the chuck and giving it a rap with a dead blow hammer.  That's how I loosen the screw on chucks for my lathe.


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## lordbeezer (Sep 14, 2021)

I’ve had good results putting hex stock in chuck and using impact wrench. Might take few bumps.


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## Firstram (Sep 14, 2021)

lordbeezer said:


> I’ve had good results putting hex stock in chuck and using impact wrench. Might take few bumps.


That's a good idea!


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## Perplexed (Sep 14, 2021)

lordbeezer said:


> I’ve had good results putting hex stock in chuck and using impact wrench. Might take few bumps.



Yes, good idea - but I still need to immobilize the spindle first, as it doesn’t have a lock feature.  So my research now is how to effect that immobilization; after that, loosening up the chuck should be a piece of cake.  The block of HDPE in the gears does stop the spindle from turning, but there’s still a bit of play, and the block is prone to falling out with just a slight release of pressure.   I’m looking for total and reliable lock


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## jwmelvin (Sep 14, 2021)

The spindle nose has radial holes for that purpose. Make or buy a pin spanner. It need not be perfect or beautiful.


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## fitterman1 (Sep 14, 2021)

I've never seen a chuck this tight before.
Silly as it might seem, have you considered the fact that it might have a lefthand spindle thread?
I know it would be a freak of nature to have one as the spindle would be exactly the same as the g0602 model, and i know mine is right hand thread.
I would resort to heat  and some form of penetrene as the only way of getting it off, in conjunction with a loaded torque bar.


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## Perplexed (Sep 14, 2021)

fitterman1 said:


> I've never seen a chuck this tight before.
> Silly as it might seem, have you considered the fact that it might have a lefthand spindle thread?



Certainly is stuck but good.  So much that I considered left-hand threads, a hidden locking screw somewhere, or even just rust.  But I went by the manual that came with the lathe, and it specifically said, “Turn the chuck in a counter-clockwise direction to remove.”  And according to the manual, there are two locking tabs, which I had already removed, and that’s it.  Then unscrew the chuck to remove.

I shone a flashlight everywhere I could, but no sign of any rust, either.  Heck, I used so much penetrating oil that I’ll probably get a stream of the stuff pouring out of the spindle whenever I manage to remove the chuck.


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## fitterman1 (Sep 14, 2021)

Then the last option i see for you apart from dismantling is this.
Get or make the previously mentioned pin spanner and fit it to the hole on the spindle and cut a piece of wood to fit between its back and the ways of the bed.
Make it a jam fit or close to.
Put a thick wall tube of good fit over its handle upto the head.
Cut some 4 x 2 to length so that when the c spanner is horizontal and underneath the spindle,it reaches to the floor and supports the tube.
Get some steel hex bar of the biggest size that will fit  right into the chuck and tighten well.
Get some stillsons that large they're unbreakable and attach to said hex bar.
Put an extension pipe on stillson handle.
Make sure you protect the ways sufficiently to prevent damage.
Be careful how you orientate the stillsons, if you have a horizontal pin spanner bar, have the stillsons bar a little higher, this will prevent you tipping the lathe over unless its bolted down.
Lean on that bar until something gives.
Bear in mind the weakest link is the pin spanner and that may let go first. It needs to be solidly fitted.
If this doesn't work take the chuck and spindle out together and send to Grizzly and ***** hard about getting the chuck off.


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## Long Roof (Sep 14, 2021)

Did you check to see if there are set screws on the backside of the chuck that need to be removed to allow unthreading? I think they are to keep the chuck from unthreading if it is run in reverse. Mine has them.


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## fitterman1 (Sep 14, 2021)

Yes, he's done that.


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## fitterman1 (Sep 14, 2021)

I think Purplexed's problem is a combination of a tight unlubricated thread which may have galled itself together ( think friction weld ) and the register and chuck mating faces having an incredible amount of sticktion.


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## Bi11Hudson (Sep 15, 2021)

Bi11Hudson said:


> 'Way back in the dark ages when I was just starting with _industrial _electrical work, I ran a lot of rigid conduit. I mean a *LOT*, as I was one of the younger guys in the shop and could contort to fit the old(ca1896) mill building. Mostly 3/4 inch rigid which equates to 3/4 inch schedule 40 galvanized water pipe. I got so strong in my hands I could assemble a conduit run by hand that needed a pipe wrench to undo. That was a long time ago, but the memories are still there.
> 
> *Which brings me to the problem at hand*. There were instances of 3/4 rigid laid directly on a concrete floor where it could be run over by forklifts and the like. A trick I soon learned was to attempt to *tighten* the joint before loosening it.. Not much, just enough to get it to "creak" or squeel once. On old galvanized pipe, fasteners, most any super tight connection, it did help. Even the longest pipe wrenches would find things easier. It was an old school millwright that showed me the trick.
> 
> ...


Galling was the idea behind tightening it slightly before unscrewing it. I stand by my earlier comment to that effect. My machines (2) have threaded spindles and no way to reliably lock the spindle. *There is the backgearing on the big machine, a good way to break a tooth on the gear**s*. The impact wrench will play well here. Preferably with a piece of hex stock but a bolt tightened up in the chuck will serve almost as well. An air driven impact wrench is better, but there is a hand impact wrench used widely by motorcyclists. Just be sure to strike the wrench, not the machine. Try one blow to tighten then several to loosen. Use a heavy hammer, a rubber hammer won't cut it. I have a six pound drilling hammer for that purpose alone. Don't bother trying to lock the spindle, just shock it loose.

.


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## lordbeezer (Sep 15, 2021)

Was referring to a air impact. Might should have said. Problem with using a bolt it will move a little taking shock value away.


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## pdentrem (Sep 15, 2021)

Use a large coupling nut with impact gun, air or electric. No need to lock the spindle likely, just the frictional losses in the drivetrain should be enough.
Pierre


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## tq60 (Sep 15, 2021)

Old school is to place chuck key in and tap that.

But given all you have done something else.

Get a bar bell weight or an automotive disk brake rotor.

Find the biggest diameter piece of metal that you can grab with the chuck and get it as tight as you can.

Get a Worn out or ugly brazed carbide and place in your tool holder upside down.

Adjust height so it bites, does not need to be on center but close as possible.

Run in slowest speed REVERSE and take assorted cuts.

Sent from my SM-G781V using Tapatalk


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## SLK001 (Sep 16, 2021)

You need to make one of these.  Using it to grip the spindle, you should be able to remove the chuck.  You'll need to modify the dimensions to fit your lathe and everything can be made with a lathe, a hacksaw and a file.

If you can grip the outside of your spindle at the rear of the headstock, a more rough tool could be made with a 4" x 4" piece of 1/2" aluminum.  Drill a hole in the center of the piece the exact size of your spindle at the rear, then drill two holes on either side from the side of the piece (not the face) for a 5/16" tap (these two holes will be used to hold the two pieces together once cut).  Cut the piece in half, cutting across the two tap holes, then open up the two holes on one piece for a 5/16" clearance and tap the two holes in the other piece.  Now get a piece of flat bar and drill two clearance holes for a 5/16" bolt at one end, spaced at the same distance as the two bolt holes in the 4" x 4" piece.  Mount this contraption on the end of the spindle and tighten the 5/16" bolts (through the flat bar).  Using this and a bar across the face of your chuck, you should be able to remove your chuck.

If *this *doesn't work, you may want to consider turning the chuck backplate off the spindle (reduce it to dust).


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## Bi11Hudson (Sep 16, 2021)

For *future* use, antiseize compound is designed just for this purpose.

.


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## SLK001 (Sep 16, 2021)

For *future *use, cut a "washer" out of parchment paper that will fit between the shoulder of your spindle and a chuck.  This will keep you chuck from jamming against the spindle and locking itself up hard.  Also, whenever you spin on a chuck, make sure it is squeaky clean.  Any swarf in your threads is almost guaranteed to jam your chuck.  If when spinning it on by hand you feel any resistance, or roughness, remove it and clean it again.


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## Weldingrod1 (Sep 17, 2021)

Even sneakier is a thin washer made of plastic, specifically one that can be dissolved with acetone!

Sent from my SM-G892A using Tapatalk


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## fitterman1 (Sep 19, 2021)

All great tips, but lets help him get it off first


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## woodchucker (Sep 19, 2021)

still not off. I haven't followed for a while.
So I used to fly F3b gliders, to do winch testing we would wrap the winch drum with rope or better yet, webbing like truck webbing. the more turns the less chance of slipping. The winch cannot turn, it must be a complete stall for the resistance test.

So do the same, get webbing, wrap it around the pulleys, and keep it tight, rather than grip a jaw which can break, or break the chuck casting, use the whole chuck... if it's a 3 jaw, get a piece of hex and tighten it in the jaws. if 4jaw get a square. That's what you'll put the wrench on... if you have enough wraps it won't move... if it does, get some fan belt dressing for the first couple of wraps, that will provide enough of a grip.


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