On 27/12/2013 8:42 PM, KG wrote:
On Thu, 26 Dec 2013 17:20:35 -0800 (PST), wrote:

On Thursday, December 26, 2013 8:18:08 PM UTC-5, wrote:
On Thursday, December 26, 2013 7:32:06 PM UTC-5, Doug White wrote:

The collegiate pistol team I help coach has two Russian target air



pistols that have broken cocking linkages. I have replacement parts,



but I need to disassemble a linkage that has a swaged pin in it. The



ends of the pin are even with the sides of a piece I need to rescue



undamaged. I had originally planned on drilling/milling out the center



of the swaged part enough to press the pin out, but I discovered that



the pin is free to rotate. There's nothing exposed enough to hang onto



that I don't need to largely cut away.







I can probably grind out the swaged bit VERY carefully with a Dremel,



but it's going to be tedious & fussy.







The pins are about 5/16" in diameter, and each end has a shallow drilled



out section. It looks like they pressed ball bearings into the ends to



spread them. The linkage the pin goes through is countersunk on both



sides, so the swaged bits hold everything together.







There a picture he







http://www.pyramydair.com/blog/image...inkage-web.jpg







The pin is the large one with the dimple just left of center in the



image.







The only way I can think of to physically hang onto the pin is to make



an expanding collet that goes into the drilled out pocket on the far end



of the pin. That is going to be tenuous at best, and it's a lot of work



to fabricate for a high likelihood of failure.







One other option would be to crazy glue everything together, mill out



the swaged bit, and then soak it in acetone until the pieces free up.



That assumes the crazy glue can handle the machining forces.







Before I drag out the Dremel, does anyone have any better sugestions?







Thanks!







Doug White



If you can tolerate the pin spinning in the hole perhaps quite a bit I've found drilling rotating pins works if you angle the piece, idea is to angle the part so the drill spins the pin but off-center, on 'average' there will be a part where the bit is hitting where the bit surface speed will be larger than the pins.



Maybe you could CA or loc-tite a small metal rod in the drilled end and clamp the rod in the vise?



Dave

BTW CA gets gummy and lets go at a fairly low temp if you get tired of waiting for acetone to do its thing.

Another suggestion is to mount 2 drills in a lathe, place the center punched pin
between them and slowly turn it. One or both drills will intermittently grab and give
you a hole that you may use an easy out in to allow you to drill out the other end.
Please let us know what works.

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To a conservatist's it truly is a free country,
YOU may do whatever they wish. KG



you beat me to it! That'd be my approach too.