Stuck mandrel. Any tips?

[webmonk]

I've been in the process of moving since about August and just this week got the new shop up and running. I turned a couple of pens today and then thought I might prep a bowl as well, but when I tried to remove the mandrel, I found out that after a few months in storage she didn't want to budge.

I tried hitting it harder than I thought I should. I sprayed WD-40 around the collar and through the back side, waited, and beat on it again. I tried using a wrench to put some twisting action on it while hitting it and that didn't help. Then I hit it some more (mostly to let out the frustration.) Still no joy.

Anyone have any suggestions for how to coax it out? I'm sure that the bigger hammer technique would do it, but I'm also trying not to damage the lathe. It's a Jet Mini so I'm not sure how much abuse I can give it.

Thanks!

 

[woodmarc]

Try a little liquid wrench. Put a small amount on the taper adapter and lightly tap the adapter to provide a vibration to draw the liquid into the taper. This should help loosen the adapter. it make take a while, I would take it easy, you don't want to ruin the internal taper.

 

[Randy_]

Be careful about pounding too hard on that mandrel or you could possibly damage the bearings. You might also try a little heat on the end of the spindle. I would start off with a hairdryer first. If that doesn't work you could move up to a propane torch; but again, be careful as too much heat could cause a problem too.

WD-40 or any other penetrating oil would be my first choice and you might need to give it a full 24 hours to work with several applications during the window. Good luck!!

 

[usfwood]

If the taper has frozen from corosion, then either penetratiing oil should help. Liquid wrench and a little heat as Randy said should help. A better rust solvent is PB Buster. It is available in some auto parts stores. I can't remember if I got mine in Autozone or Discount Auto. It is one of the best I have used for frozen/rusted engine bolts. Also, along with the heat, you might try tapping gently on the side of the mandrel where it enters the spindle. Not too hard, but a few firm taps on the side of the mandrel and then rotate the mandrel a few degrees then tap again. Repeat this untill you have rotated the mandrel one full revolution. That might help loosen it up to where hitting the ejection rod on the back should release the taper.

D

 

[Skye]

My vote is PB Blaster.

 

[Randy_]

And just one additional comment about the use of the heat for clarification. The idea here is to heat up the end of the spindle so it will expand just hair and release the arbor that is stuck in the spindle. There will probably be a good section of the arbor sticking out of the end of the spindle. You need to use something to shield the end of the arbor from the heat as you want the spindle to be hotter than the arbor. You are limited only by your imagination as to how the shield is constructed. First thing that comes to my mind is something cut of an empty tin can.

 

[RussFairfield]

Grab it with a pair of pliers and give it a twist as you hit the other end with the knockout bar.

 

[Randy_]

???OK, I give up?? What good does it do to give it a twist?? Unless it has a spindle lock, which most lathes don't(including the JET mini), giving it a twist will just spin the spindle and not have any real effect on removing the arbor.....or, at least, so it would seem.

 

[ctEaglesc]

No one has mentioned it, but are you spraying the aerosol from the end you place the knoc out bar in?
You didn't say what brand of mandrel/adapter you are using, but the variety from berea uses a 1/4 x 28 boltthread in the M2 adapter.This is available at most hardware stores.
Unscrew the MANDREL from the M2 adapter.
Thread the bolt in that tapped hole.That is probably rusted as well I would put a little WD40 in the hole before inserting the bolt.
Use a strap wrench on the threads of the spindle and a wrench on the bolt.
turn in opposite directions similar to loosening up the collet on a router bit.
Clean the inside of the M2 spinle before using it again.
Clean the outside of the adapter before using it again.
(This should solve the problems.

(At least you didn't glue the post of the tool rest to your banjo.)

 

[webmonk]

Thanks for all the advice so far! I'm not sure if I'll have a chance to try it today, but I'll give it a shot this weekend...

ctEaglesc: I tried spraying it in from both sides (around where the mandrel goes in and through the knockout bar hole). I even held the lathe upright in hopes of it draining down around it more. The mandrel is the adjustable kind but I can't recall the brand.

 

[webmonk]

Hmm... I'll give that another shot after the WD-40 has had some time to work. The mandrel I have has a shape that allows you to get a wrench on it and my lathe has a hole in it that you can put a bar through to get some leverage. I tried manually twisting but it didn't work and even wedging the bar and hitting the wrench with a hammer didn't get it to twist.

 

[webmonk]

Okay, after some messing around with it the mandrel came loose. What I ended up doing was injecting a bunch of PB Blaster, waiting a few minutes, taking the blowtorch to it and getting it really hot, then beating on it like crazy with the knockout rod and a hammer. On about the 10th hit it popped out. Now I'm waiting for things to cool down so I can assess the damage.

Thanks for all the advice!