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Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 1:50 pm
by wa2crk
Looks like in Pic #4 the left side of the casting is indeed cracked but pic #5 it looks more like a seam from the casting mold.
The galvanic corrosion that JPG alluded to will cause the pieces to swell so that they virtually are welded together.
I see from your original post that you are using a some penetrating oil which good. Try to raise the stop collars which will give some more working room. If you can loosen the set screws on the stop collars and they don' want to move a strap wrench may be useful. You can't rotate the tubes in the tailstock casting, they are pressed into the casting.
Taking a second look at your pics it looks as though the tubes from the tailstock are projecting through the hinge casting. If that is the case some judicial tapping may force the tailstock upward.
Bill V

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 1:59 pm
by dusty
wa2crk wrote:Looks like in Pic #4 the left side of the casting is indeed cracked but pic #5 it looks more like a seam from the casting mold.
The galvanic corrosion that JPG alluded to will cause the pieces to swell so that they virtually are welded together.
I see from your original post that you are using a some penetrating oil which good. Try to raise the stop collars which will give some more working room. If you can loosen the set screws on the stop collars and they don' want to move a strap wrench may be useful. You can't rotate the tubes in the tailstock casting, they are pressed into the casting.
Taking a second look at your pics it looks as though the tubes from the tailstock are projecting through the hinge casting. If that is the case some judicial tapping may force the tailstock upward.
Bill V
I think you are looking at both my three pictures and the original post. The cracked base arm is mine. In the OPs only picture it appears as though there is a gap between the stop rings and the base arm - indication that they were not fully inserted.

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 2:04 pm
by JPG
Crack, or mold seam????

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 7:35 pm
by ChrisNeilan
I think it may be time to use heat. Not a welding torch, but maybe a plumbers propane torch or even a heat gun. Tap the tailstock down gently when heated, soak again with pb blaster. Heat it up and tap it out from the bottom being careful that both posts are moved equally to maintain paralell. If they get cocked on the way out they can really get jammed up. When you finally get it out, clean the posts and sockets (maybe use 400 grit sandpaper) and wax the heck out of them. Buff it out good and you should be problem free.
Good luck

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 9:10 pm
by Hobbyman2
My bad ..ignore my post,,, I thought for sure I had the tubes out once ,,




Hobbyman2

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 9:31 pm
by carpfisher
Great list of things to try. Thanks for all the advice. I am on business travel and will work at it when I get back on Weds. I think Dusty has the best option to start with.There is still clearance to insert further in to the casting. Wack it down first to break I suspect is as JPG mentioned, galvanic corrosion.
More to follow later...

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 10:31 pm
by wa2crk
JPG wrote:Crack, or mold seam????
That is what I saw. one pic looks like a crack and the other looks like a mold seam.
Bill V

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 10:35 pm
by JPG
I think the 'crack' is caused by incomplete melding at the surface at the seam. If so it is likely shallow.

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 10:39 pm
by wa2crk
Dusty
It looks like the posts of your tailstock go below the base arm casting.Don't think I ever saw any go that low.
Bill V

Re: Tailstock stuck in MK V

Posted: Mon Feb 20, 2017 10:58 pm
by dusty
carpfisher wrote:Great list of things to try. Thanks for all the advice. I am on business travel and will work at it when I get back on Weds. I think Dusty has the best option to start with.There is still clearance to insert further in to the casting. Wack it down first to break I suspect is as JPG mentioned, galvanic corrosion.
More to follow later...
Maybe you could squeeze (press ) it down. Wack is a scarey word when working with cast.