Spring Pin Removal

[Stepside]

I am taking apart the drive system on my Clausing Horizontal Mill. There two parts bolted together but aligned with a pair if spring pins/roll pins. The problem is they are driven into a blind hole. What is the trick to remove them. There is not a decent place to pry or drive them apart. Diameter is about 1/8 inch.

[oxford]

A picture of what you are working with would help.

Maybe try grease in the roll pin hole and a punch just smaller than the hole. It might give you enough hydraulic pressure to either raise the pin up enough to pull it out or separate the parts to get something in between.

You may lose to much grease/pressure out of the slot in the pin for this to work.

[Mcgyver]

Maybe try grease in the roll pin hole and a punch just smaller than the hole. .

Who puts a roll pin in a blind hole? Grrrrr. As you're not going to get a good hydraulic seal (the seam if nothing else), add finely torn up bits of paper towel to the grease. keep add more, hammer a bit, repeat. It will eventually block the holes and the pin will come out

[wbldon]

I have to agree with Mcgyver, I don't understand using roll pins in a blind hole. Two other thoughts.. You might be able to drill them out enough to pick out the pieces if you can drill it out so the walls are thin enough. Second you could try tapping it, run a screw into it and pull on the screw to remove. Also you might be able to take it to a locale machine shop and have them use a tap popper to burn it out.

[flathead4]

Drill it until there is just a thin sleeve in there and pick it out with an appropriate tool. The right size drill bit might grab enough to pull it out. Maybe soak it in Kroil before you start. Or - is it possible to run a tap into the roll pin and then screw in some all thread or a bolt. Build something to jack it out. Since you say it is a blind hole, is there something better that can be put back in there to facilitate easier removal or just the way it is?

[flathead4]

I have to agree with Mcgyver, I don't understand using roll pins in a blind hole. Two other thoughts.. You might be able to drill them out enough to pick out the pieces if you can drill it out so the walls are thin enough. Second you could try tapping it, run a screw into it and pull on the screw to remove. Also you might be able to take it to a locale machine shop and have them use a tap popper to burn it out.

Holy cow! We read each others mind at the same time.

[wierdscience]

If there is enough sticking out, I have had good success by grabbing them with a pair of end nippers and levering them out little by little.

[Mr Fixit]

I've had good luck with a pair of modified vise grips that have a slide hammer on the end, I grab the pin and give it a tug and they come out. Of course you need to replace the pin, but that's the easy part.

Let us know how you come out on this one, as we all might learn something.

TX
Mr fixit for the family
Chris

[mattthemuppet]

I'd try threading a bolt or maybe a tap in, then use a small pry bar or similar to pry if out

[lakeside53]

yes, tap (it will be tough) into them, or if the spiral type, unwind in the correct direction with a square or whatever center. The trick (obvious) is NOT to expand them.

[JRouche]

Hahaah.. I didnt read the stuff but is it actually a blind hole? No

If it is easy fix.

Un-blind it with the tool of your choice. Then you pop it out. JR

[Arcane]

Just another suggestion... is it possible to use the spring pins/roll pins as guide bushing for a small drill and drill the rest of the way through the shaft? Then you know where to drill a hole from the other side that will let you use a punch to drift them out. If that's not possible maybe you can still figure out where to drill from the opposite side.

[Paul Alciatore]

Are you really sure it is a blind hole? I have seen putty used before painting a machine. It can fill in a crack or hole to make the paint job look nicer. If it is painted, try probing the other side with a sharp tool (scribe or pointed knife) and see if it is really solid metal there.

If the pins can not be driven out from the other side, I would just unbolt the two pieces and slowly work them back and forth on the pins until you can get a knife edge between them. Then wedge then apart with the knife and then thicker implements until one of them pops off the pins. Then the pins can be pulled out of the other part.

[Mcgyver]

I'd try threading a bolt or maybe a tap in, then use a small pry bar or similar to pry if out

the pins are usually smallish and the problem with any sort of manipulation of the centre is 1) it makes it tighter in the bore and 2) if it breaks you are really pooched. Do what I said, bits of paper towel in grease and press it into hole, hammer with punch. do it 500 times if needed.... It takes some time but is a bit fool proof. The grease will keep squirting out, seemingly ineffective, but its depositing the fiber that eventually clogs the greases escape route. I've used it to pop a unshielded press fit bearing out of a blind hole for example, something close impossible most any other way.

[rodelu]

I used to work in a MA place that made positioning devices and spring pins were used to keep slider bearings in place. Those pins (perhaps 3/32"in diameter) were inserted in blind holes in aluminum and when they had to be removed a slot was cut in the protruding part with a Dremel tool and they were levered out.