Removing a mis-aligned roll pin

[iron bark]

Well chaps, it is time to fess up. I am a d!ckhead, because whilst re-assembling my lathe, I was re-inserting to the roll pin in the carriage feed rod, and after getting it about 2/3 the way through, I realized the holes were mis-aligned, so now I have a stuck roll pin.

I have removed and replaced plenty in the past and always checked the alignment before driving the pin in, but on this occasion, late at night, poor light, and the fact that it is in a bugger of a position, I pushed on.

Problem now is, how to get it out. It is so badly out of alignment that I can only see a fraction of the pin from the other side, so a punch won't work.

Can it be drilled out, without damaging the hole?

Should I try to anneal it before drilling?

Pic attached showing the offending pin, it is the lower one, and there is about 3/16" protruding.
236971


You may well ask why I want it out, because things are working as it is, but I can't stand looking at such a stupid mistake, AND, I may want to take it apart again one day.

Any suggestions would be appreciated.

Thanks,

Ned

[Ueee]

Hi Ned,
Have you tried getting hold of the end with a pair of vise grips (so they close up the pin) and pulling? you can also try to lever the vise grips off the shaft with a large screwdriver or small pry bar.

[NCArcher]

Drill it out with a drill bit smaller than the hole. It will leave a thin walled roll pin which should come out easily enough. Maybe :shrug: Perhaps you should wait to hear from more experienced metal heads. :D

[Bryan]

I was going to suggest a self-tapping screw and a slide hammer but then I realised the screw will tend to expand the pin. Could you tap a proper thread in it? I'm doubtful, those pins are pretty tough. Sorry, just thinking aloud. Sometimes that can trigger other ideas.

[nadroj]

Another thing to try:
Put a pin or nail in the hollow centre, then use vice grips. It could help prevent it slipping off due to it collapsing inwards.

Jordan

[Blu_Rock]

getting hold of the end with a pair of vise grips (so they close up the pin) and pulling? you can also try to lever the vise grips off the shaft with a large screwdriver or small pry bar.

Second this approach... make sure those vice grips are gripping the pin REAL tight.

[morrisman]

How did it manage to get in that far with the holes misaligned !

I just did a google on roll pins

Can you somehow turn the shaft or that collar and align the holes , this might loosen it .

Mike

[Ueee]

How did it manage to get in that far with the holes misaligned !

I just did a google on roll pins

Can you somehow turn the shaft or that collar and align the holes , this might loosen it .

Mike

Mike,
I'm guessing that the roll pin hole is not drilled on center and Ned has put the pin in with the 2 parts 180deg out.

[.RC.]

Roll pins are soft, just drill it out....

Hard to believe they are that badly misaligned you cannot turn the shaft around and just punch it out wiith a small punch...

[iron bark]

Mike,
I'm guessing that the roll pin hole is not drilled on center and Ned has put the pin in with the 2 parts 180deg out.

Spot on, I am 180 deg. out, and had I checked the alignment like I usually do, I wouldn't be here asking for advice. As for "how did it get that far", it felt fairly normal until I hit a dead stop.

I will go and try the suggestions so far.

Thanks,

Ned

EDIT: Tried the vice grips with a drill in the centre of the pin to stop it collapsing, but unsuccessful. I think I will give drilling it out a go. I was a bit edgy about drilling it out because I thought roll pins were very hard. I think I have a cobalt drill somewhere, so if I can find it I will try it.

[shedhappens]

Try putting a bend on the end of a punch to get around the corner to knock it out, maybe a punch that is a smaller diameter than the hole, if it is good quality roll pin it will be hard to drill and vice grip's will just slip off.

[iron bark]

Roll pins are soft, just drill it out....

Hard to believe they are that badly misaligned you cannot turn the shaft around and just punch it out wiith a small punch...


RC, you were right. The roll pin was 5mm, and the only cobalt drill I had was 5/32, which was perfect to drill out the guts of the pin. I must admit I was surprised at how easy it was to drill. I then sunk an easy-out in about 1/4" and grabbed it with a set of pincers, and it just slid out.

Thanks to all for your suggestions - PROBLEM SOLVED (I will check the alignment in future. Pity the drilling wasn't done on centre to start with)

Cheers,

Ned

[rusty steel]

If there enough of the pin protruding to put a thread on it perhaps if a nut was then screwed on you may be able to lever it out with a screwdriver or fit washers (one at a time) under the nut to withdraw it as you tighten said nut. I discarded the roll pins on my lathe and made some shear pins from free machining aluminium (2011 T3). They are 5.0mm dia. I have cut roll pins with a hacksaw so they are not too hard.
Russell

[bwal74]

Hi,

I think drilling will be the way to go. But if you try the vice grips again or can get at it with a punch, spray so WD40 or other type of lubricant onto pin/hole.

Ben

[iron bark]

If there enough of the pin protruding to put a thread on it perhaps if a nut was then screwed on you may be able to lever it out with a screwdriver or fit washers (one at a time) under the nut to withdraw it as you tighten said nut. I discarded the roll pins on my lathe and made some shear pins from free machining aluminium (2011 T3). They are 5.0mm dia. I have cut roll pins with a hacksaw so they are not too hard.
Russell

Russel,

Looks like we both posted at the same time. All sorted now, but the idea of softer shear pins sounds like a good idea in case of a "crash".

Cheers,

Ned

[iron bark]

Hi,

I think drilling will be the way to go. But if you try the vice grips again or can get at it with a punch, spray so WD40 or other type of lubricant onto pin/hole.

Ben

Thanks Ben, all sorted out now - see a couple of posts back.

Cheers,

Ned

[franco]

For future reference - crude, but it works wonders:

Frank.

[simonl]

Hi ned,

A bit late in the piece with my response but I too have had to deal with a mis-aligned roll pin. It was one of the first times I had ever dealt with or removed one. It seems to me that all roll pin holes are off centre which I did not realise until replacing and getting it most of the way in. I tried a few solutions such as the vice grips a pin punch from the other end (this found it's way either inside the pin or between the pin and the hole and added to the problem) I ended up butchering the thing to get it out. I never tried drilling it out though as I assumed they were hardened. I like the vice grip "bead breaker" that looks good!

Simon

[Stustoys]

On a side note. I think they often dont even try to get the pin in the middle. While I'm sure it can be done it would be a pain and if you got it "almost" right that would make it harder to be sure with was the right way around.

Stuart(the guy that managed to damage a machine driving a 1/2" dowel pin home that "almost" lined up. Not my best day :( )

[kwijibo99]

All a bit academic now but another method that can work here is to fill the hole through center of the pin with grease, insert a pin punch with a diameter as close as possible to the hole and give a hit with a hammer. As long as the hole is completely misaligned and blind then the pin will hydraulic out.
The same technique works when removing bearings and bushes from blind housings.
Cheers,
Greg.

[morrisman]

I was reading that some makers insert a shear pin in that locaton. If the leadscrew or drive shaft jams , the pin will shear and thus save other parts like gears from damage .

Mike

[Clubman7]

Never seen a roll pin in that position before. Have replaced a couple of taper pins for the feed shaft before.
Don't forget, you can get hardened roll pins as well.
Lucky it was a soft one to be drilled out.

[iron bark]

Never seen a roll pin in that position before. Have replaced a couple of taper pins for the feed shaft before.
Don't forget, you can get hardened roll pins as well.
Lucky it was a soft one to be drilled out.

Yes, that's interesting, I don't know how you tell the difference between a soft and hard roll pin, short of trying to cut or drill it. Maybe they use soft ones in this situation so they will shear if necessary.

(EDIT. Whilst mine did drill out easily, I did happen to have a cobalt drill of the correct size, which I used, expecting the pin to be hard

Cheers,

Ned

[rogerbaker]

I would just push it out using a pin punch form the opposite side.

Roger

[iron bark]

I would just push it out using a pin punch form the opposite side.

Roger

Sure, That's the way to do it if you can, but here we are talking about a pin that is mis-aligned such that the pin can't be got to with a punch from the other side. i.e. the hole wasn't drilled exactly in the centre of the shaft and it's collar, so if it is 180 deg out, then not all holes line up.

[joe greiner]

For future reference - crude, but it works wonders:

Frank.


Cool. Thanks.

Cheers,
Joe