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View Full Version : Removing Rool Pins from Blind Hole????!!?



madman
09-26-2013, 07:17 PM
I got a issue with some roll pins. They have been inserted into a .750 deep drilledblind hole. These roll pins are 5/32 (.15625) diameter and .750 inches long, How the heck do I drill them out? I've tried some drills but they wont touch the pin and carbides available arent long enough? Thanks for any suggestions you may have. Mike

vpt
09-26-2013, 07:32 PM
I asked this a few years ago.

Answer that worked for me was taping the pin a few turns and using a screw to pull it out.

Another popular one was find a punch that just fits inside the pin and them fill the pin with grease or candle wax and then pound the punch in hopefully driving the pin out.

Dr Stan
09-26-2013, 07:55 PM
I've partially collapsed roll pins with vice grips and pulled them out. Just pay attention to the orientation of the slit in the pin.

randyjaco
09-26-2013, 08:20 PM
First I would try screwing in a sheet metal screw and pulling it with vice grips or a body panel slide hammer. It has worked for in the past. Remember to lube the roll pin with penetrating oil first.

Randy

Arcane
09-26-2013, 09:57 PM
Which of these two types of "roll pins" are you referring to?
http://www.micromatic.com/images/3/300x300/100-302.jpghttp://www.advantecstore.com/static/luna/images/products/5/5955-FA-MI3705_SplitPin_3.JPG

KJ1I
09-26-2013, 10:23 PM
Wow. I've seen a lot of roll pins in my 63 years, including those in my Dad's 1930's vintage equipment. But I've never seen a "rolled" roll pin until your posting.

Toolguy
09-26-2013, 10:31 PM
The rolled ones are called spirol pins. Spirol may be a brand name or a generic name, don't know.

Mike Burdick
09-26-2013, 11:38 PM
This won't work in your case since the pins are so hard but for the ones I have I use a HSS tap of the appropriate size and thread the inside of the roll pin. Then use a bolt to pull the pin out. If one has the time, one can make a collar to fit over the thread on the bolt and add a nut to "jack" the pin out.

atomarc
09-26-2013, 11:47 PM
I've partially collapsed roll pins with vice grips and pulled them out. Just pay attention to the orientation of the slit in the pin.

Wonderful idea if the roll pin happens to be sticking out a bit, but that's not usually the case. Who ever dreamed up the idea of driving a roll pin into a blind hole needs to have their testes smashed with a 20 oz ball pein hammer.

Stuart

Lu47Dan
09-27-2013, 12:11 AM
Wonderful idea if the roll pin happens to be sticking out a bit, but that's not usually the case. Who ever dreamed up the idea of driving a roll pin into a blind hole needs to have their testes smashed with a 20 oz ball pein hammer.

Stuart
I have done it hundreds of times over the years, I used them for alignment pins for various projects. They work fine as long as you don't drill the holes to deep.
Dan.

darryl
09-27-2013, 12:45 AM
Well, if you're going to have your testes smashed, it would certainly be appropriate to use a ball pein hammer. However, I would most certainly decline to have this corrective treatment. :)

Paul Alciatore
09-27-2013, 01:42 AM
The simplest way, depending on the assembly they are in, would be to drill a hole from the opposite side and drive them out with a punch. But this depends on the assembly and many will not allow it. And alignment of that hole may be very difficult.

Another way would be to grind out a depression around the end of the pin and grip with needle nose vise grips. But, this may not be acceptable or possible.

atomarc
09-27-2013, 01:46 AM
Dan,

A true alignment pin would typically be a taper pin, not a roll pin. This has been my experience.

Stuart

Paul Alciatore
09-27-2013, 03:21 AM
I have seen many precision assemblies that used roll pins for alignment. Perhaps the taper pin is better for situations where the parts need to be disassembled and reassembled frequently, but the roll pins do a perfectly adequate job in many circumstances.




Dan,

A true alignment pin would typically be a taper pin, not a roll pin. This has been my experience.

Stuart

Deus Machina
09-27-2013, 05:20 AM
I've used (or seen used) a roll pin for alignment a few times. I always make sure that I can get a hold on it with vice grips if need be.
It works, but so far I've only made a mess using the grease method. I'm just unlucky, though, or perhaps the pins were too small to build up a good surface area and had a slot too large. Give it a shot. It usually works. I just have the worst luck.
I second the screw method. It doesn't have to cut good threads, just enough that the screw holds the pin stronger than the hole around it.

mike4
09-27-2013, 05:42 AM
Find a drill that will fit inside the roll pin ,drill through the blind hole , then insert a piece of rod until it is just proud of the end of the roll pin from the opposite side , weld it and the pin together , taking care not to weld it to the shaft .
When cool carefully tap the pin out using the rod to drive it out.When reassembling use the original pin and rod , that way there is no hole to gather crud.

Then next time it will be a lot easier.

Michael

Euph0ny
09-27-2013, 06:29 AM
OT: I like the tap-the-pin and use a jacking-screw method, if the pin is soft enough to be tapped.

Drilling out the "back" of the blind hole works, if it is acceptable to alter the part

I have no experience of the bang-in-grease hydraulic removal method, but it sound like one that may be better on paper than in practice. In extremis, put a stainless washer over the edge of the hole to protect it, and stick an arc-welding rod to the roll pin, to give yourself a handle on it. Lots of penetrating oil and gentle wiggling should get it out.

Slightly OT: One of my pet peeves is that people frequently gunther roll-pins by driving them with regular punches. Roll-pin punches (http://www.brownells.com/search/index.htm?k=roll-pin+punch&ksubmit=y) are the bee's knees, and can even be home-made from regular punches in a pinch without much difficulty.

Normanv
09-27-2013, 08:56 AM
You can see it being done here https://www.youtube.com/watch?v=9xRy8wGfcIk It starts at 8.30 into the video.
It is basically what Mike4 said in #16

krutch
09-27-2013, 01:08 PM
Is it possible to drill out the pins with a carbide mill of oversize diameter then plug the holes? Move the pin locations if possible and needed.

PixMan
09-27-2013, 01:41 PM
Wonderful idea if the roll pin happens to be sticking out a bit, but that's not usually the case. Who ever dreamed up the idea of driving a roll pin into a blind hole needs to have their testes smashed with a 20 oz ball pein hammer.

Stuart

Oh really? Would you smash me for doing exactly that with the (26) 1/8" x 1/2" long roll pins I used to make this box out of 1/2" thick 6061 aluminum? It's an urn (10.5" x 6.5" x 5.5") that holds my late father's ashes, purposely made to never be opened again. Made from 6 plates and not a single screw in it.

http://img.photobucket.com/albums/v466/kenm10759/Interment_1_zps67c045a0.jpg

PixMan
09-27-2013, 01:50 PM
The rolled ones are called spirol pins. Spirol may be a brand name or a generic name, don't know.

Spirol is a company not very far from me, their name is based upon the true spirally rolled springs pins they make, though they also make the slotted style and call them "slotted spring pins." The latter is far more common these days.

http://www.spirol.com/mkt/rs1.php?search=2
http://www.spirol.com/mkt/rs1.php?search=4

GNM109
09-27-2013, 05:47 PM
I discovered a broken roll pin in one of the holes in the table of my Webb Mill when I was refurbishing it several years ago. The hole was one of two used to locate the hand wheel bearing housing on the right side of the table. The hole was about an inch deep and the broken off roll pin section was about a half inch long and in about an eighth of an inch.

I thought about drilling it out with a carbide drill but instead came up with the idea to turn a hardened screw into the piece to attempt to remove it. I turned the screw tightly into the center of the roll pin section and then I levered it out with a pair of side cutters. lt actually came out rather nicely but it was under some tension and it cracked into two pieces when it came out.

It worked for me. Here is the evidence.


http://i144.photobucket.com/albums/r188/gnm109/BrokenRollPin_zpse9d83eb2.jpg

metalmagpie
09-27-2013, 05:55 PM
Wonderful idea if the roll pin happens to be sticking out a bit, but that's not usually the case. Who ever dreamed up the idea of driving a roll pin into a blind hole needs to have their testes smashed with a 20 oz ball pein hammer.

Stuart

Oh, that's not so bad. Wait until you get a taper pin jammed in a blind hole!

metalmagpie

JoeLee
09-27-2013, 08:13 PM
The pin on the left is the original roll pin later replaced by what is now called the split pin. Some people still call them roll pins.
I'll bet the split pins are easier and cheaper to make and they hold better.

Rarely do I ever see the rolled type, only in real old stuff like my 1940's Morgan wood working vise where they are used to hold the end caps on the handle.

If you have the capability to TIG weld you might try fusing a piece of rod to the pin and try pulling it out. I've done it many times in the past.

JL...............