Help desperately needed

[Newbster]

I am going to suggest something that may seem very strange to some people. Take two hammers hold the head of one under the part and then give the top a sharp tap from the opposite side rotate the shaft 1/4 of a turn, do this a number of times around the circumference tapping every time you turn it. This may help to shock anything like rust and free up the thread.
I use to do this when I was a plant mechanic.
By using two hammers there is less likely to damage the part. I say a sharp tap no need to belt the living daylights out of it.

Notstrange to me, make the hammer you are using as the anvil, bigger thn the one you are hitting with. And keep going!

Thanks gents for the input I'm going to try that right now. Should I support the base hammer while doing the orbit so as to prevent any flexing or will hand-holding and obviously bracing against the the lathe bed or rest do the job?

[Derek]

I am going to suggest something that may seem very strange to some people. Take two hammers hold the head of one under the part and then give the top a sharp tap from the opposite side rotate the shaft 1/4 of a turn, do this a number of times around the circumference tapping every time you turn it. This may help to shock anything like rust and free up the thread.
I use to do this when I was a plant mechanic.
By using two hammers there is less likely to damage the part. I say a sharp tap no need to belt the living daylights out of it.

Notstrange to me, make the hammer you are using as the anvil, bigger thn the one you are hitting with. And keep going!

Thanks gents for the input I'm going to try that right now. Should I support the base hammer while doing the orbit so as to prevent any flexing or will hand-holding and obviously bracing against the the lathe bed or rest do the job?

Just hold the lower hammer firmly against the underside of the piece that we believe should come unscrewed. It will bounce off when you give the top of it a sharp tap

[Derek]

Is it a left or right hand thread ?

It would be a standard right-hand thread otherwise if it was left hand then any screwed on fitting will undo.

[Newbster]

SHE'S OFF!!!!

For those of you who took the time to help an old man out I cannot thank you enough. The bugger is off FINALLY and it was combination of almost everything all of you had suggsted. Heat, 2 hammers, reboring the tommy hole (which incidentally had no thread underneath as you can see from the photo) and then 20st of down on top of the Stilson when it suddenly creaked like a broken door.

Again thank you so so much everyone. You've made my Christmas because I honestly didn't have the money to be spending but a new chuck is on its way. 

[Twisted Trees]

Good to know, now be sure to turn something that needs a chuck and not a spindle drive  clean up the thread, do not lubricate with anything wet or dust will stick to it, and get in the habit of unscrewing whatever you have been using at the end of the day. It's all to easy to think "Oh I will leave that on for tomorrow" then get distracted and come back in a months time to find it stuck.

[Newbster]

Good to know, now be sure to turn something that needs a chuck and not a spindle drive  clean up the thread, do not lubricate with anything wet or dust will stick to it, and get in the habit of unscrewing whatever you have been using at the end of the day. It's all to easy to think "Oh I will leave that on for tomorrow" then get distracted and come back in a months time to find it stuck.

Many thanks for the tip. I was going to go at it with a bit of bread soda and vinegar but would a bit of wax or axle grease be any harm?

[Lazurus]

I use a good quality marine was on everything.

[Twisted Trees]

Good to know, now be sure to turn something that needs a chuck and not a spindle drive  clean up the thread, do not lubricate with anything wet or dust will stick to it, and get in the habit of unscrewing whatever you have been using at the end of the day. It's all to easy to think "Oh I will leave that on for tomorrow" then get distracted and come back in a months time to find it stuck.

Many thanks for the tip. I was going to go at it with a bit of bread soda and vinegar but would a bit of wax or axle grease be any harm?

Machine wax, or PTFE basically dry lubricants are best, axle grease will collect dust and cause problems. But remove anything screwed on every night and leave the thread dry and clean and you shouldn't have any further problems.

[Ianparkin]

Out of interest what thread is it?

[Newbster]

Out of interest what thread is it?

Right hand thread and Ian thank you again for all your help

[Ianparkin]

Well i meant what size it was  !!
What chuck have you ordered?

[Ianparkin]

Just looking at your picture of the removed drive are you sure that the tommy bar hole hasn’t got a grub screw down the hole as it looks like something has described a thread on the register?

[Newbster]

Well i meant what size it was  !!
What chuck have you ordered?

Nova with a 19.1mm thread is what I ordered which seems to be about right based on the photos attached.

[Ianparkin]

Looks like a 24mm x 3mm pitch from those pics

[Ianparkin]

Or if its imperial may be 1” 8tpi