Roll pin removal

[John Rudd]

Ok today's problem......

I need to remove a roll pin (or whatever you want to call it) from the compound slide....
As you can see it is in a blind hole...
Suggestions for getting it out....and I don't an EDM machine....

[Lew_Merrick_PE]

John,

It is possible (but not bloody likely) that the roll pin has threads on the ID.  They are not part of any standard, but they fall in the same class is dowel pins with pull threads.

It is also (sometimes) possible to remove such beasties with an easy-out.  [These work best on austenitic stainless steel pins.]

[John Rudd]

Lewis,
Thanks for the suggestion, while awaiting the suggestions rolling in...... I was thinking maybe an Ezi-Out...if I have one small enough....

I'll give it a try...

[appletree]

Would it be possible to drill out with a satellite drill or maybe solid carbide? Roll pins are usually very hard, why do you want it out? Can you afford to sacrifice and machine the whole bolt bit away on the underside? Will the spindle not hammer back through? How else is it located, its a bit difficult to get relative sizes, sorry about all the questions. 

[John Rudd]

Don't gave Stellite or carbide drills, only HSS....
Don't want to sacrifice the existing tool post bolt in case I return the machine to 'as bought' state...so cutting is a no no.....
The spindle will not push out.... I tried in my hydraulic press!!

I think the bottom bit is a shoulder bolt screwed into the main part we see from the top...locked in place with the toll pin...but I could be wrong....I tried locking two nuts together in a vain attempt to undo it.....

[awemawson]

Can you start a self tapping screw in it, and lever it out using the head. Self tappers are pretty hard steel. Obvious you don't want to go in too far and expand the pin much.

If you are really stuck post it to me and I'll pop it ou on the die sinker edm.

[John Rudd]

If you are really stuck post it to me and I'll pop it ou on the die sinker edm.

Hmm. Thought you might... Thanks for the offer Andrew.... All is not lost... Yet!...

I'll give the s-t a go if the Ezi Out doesn't....

[lordedmond]

John

That's similar  to a Myford top slide

It's only a antirotation pin just press out the stud from the top then you can deal with the pin as it will be accesible

Stuart

[awemawson]

It's not entirely clear to me how that is assembled. Is the upper part screwed to the lower part with the pin or what.

If so can one or the other be firmly gripped in a collet, and the pin sheared off so that it can be removed in two parts ?

Cross sectional C o Cad sketch please 

[John Rudd]

John

That's similar  to a Myford top slide

It's only a antirotation pin just press out the stud from the top then you can deal with the pin as it will be accesible

Stuart

I tried pressing it out.....won't budge.....grrrr.

The pin is 3mm dia and 16 mm long according to the manual....

[John Rudd]

Cross sectional C o Cad sketch please 

Ok, got my Etchasketch out.......

[David Jupp]

I'd have thought it's more likely to be a simple anti-rotation pin as per Stuart's post.   Maybe some Loctite used in initial assembly (might explain difficulty pressing it out)?  Maybe warm things up, then try again...

[appletree]

Can you drill directly above the pin from the top and punch the pin out from the top, especially if it’s as per your drawing. If the two bits are lactated together apply some heat to the “stud” bit and sink some heat into the threads.
 

[awemawson]

If as your sketch, the pin doesn't penetrate the upper cylindrical part, grip it in a collet or three jaw chuck, and tap the slide with a soft mallet to unscrew the upper from the lower.

[John Rudd]

I'll give it a try.....

But my thoughts are that the two parts were assembled and then locked together with the pin....( that's what I would do)

[John Rudd]

Ok,
The Ezi Out option is a non starter, my smallest won't grip the inside of the pin....

I also tried gripping in the chuck (3 jaw ) and striking with a hammer ( shaft end ) but it's not budging...


Heat is the next option.....( hot air gun )......

[awemawson]

You better start saving up postage stamps for a two way journey 

[DavidA]

John,

Maybe you can drill right through the hole in the roll pin using a small drill,  then turn the thing over and drill at the pin diameter back toward the pin and then punch it out via the new hole.

Dave.

[John Rudd]

You better start saving up postage stamps for a two way journey 

No need it's out....apart,in bits  .....yippeeeee

I put it back on the press, low and behold it popped out....

So the pin  just stops the post bolt from turning....simple but effective..

So, now I need to get on with making a new one for my ( yet to buy) qctp....

Thanks for your help guys....much appreciated...

[appletree]

That old saying “where there’s a will there’s a way"

[DavidA]

 John,

The removed pin doesn't appear to be quite like your sketch.

Dave,

[John Rudd]

If you look at the second foto, the pin fits thru the bottom....as in my sketch, see the lower drawing left hand side part that I thought was a shouldered bolt but isn't....the whole thing is one assembly...