Here's a text I've posted many times on many sites, so I'll give it to you guys here. Sorry I didn't respond to you, Bullet. Must have missed that email.
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How to Press Out a Barrel Pin
Shop Press Method:
Materials
1) I have several pieces of 1/4" iron that I use in various ways while building. Several have holes drilled through them. Others are dimpled to act as bucking plates.
2) I also have many pieces of hex-wrenches (which is made of the strongest steel imaginable) which I use as punches. I cut hex-wrenches into lengths from 5mm to 1cm and 4cm to 10cm. I used hex wrenches that were (roughly) the same diameter as my barrel pin. To cut these to length I vise them down, and use my circular saw with a grinding blade ($10 at Home Dept) to cut off lengths. The grinding blade is the bomb! It goes through ANY type of steel FAST. Finally I dress up the pieces so their ends are flat. This step is critical. It's what keeps the punches from flying across the room when pressure is applied to them. It is this piece of hex-wrench that I will refer to as a punch.
Method:
I place a 1/4" shim under the rear sight block and lay the barrel/trunnion on the arbor plate of the press. I place my 5mm piece of hex-wrench in the punch position on top of the barrel pin, and lower the press onto the hex-wrench punch. The shim under the sight block keeps the trunnion from rotating, and the very short length of the punch and its flat ends keep it from popping out (usually) when pressure is applied.
Of course the barrel tends to roll forward off the plate until the punch starts to press on it, but after that it no longer is an issue. I always stand behind the side vertical member of the press whenever I use it. I do not wish to have to explain to hospital staff how that piece of steel got embedded in my forehead. As I apply pressure the very short punch will manage the high pressure without having to deal with the very large moment (engineering term) of a long punch. It is the large moment which will cause your punch to snap off of your press and fly across the room. By keeping the punch short I reduce the moment to a manageable one while I pop loose the pin.
This is the critical point. Once the pin is popped loose, and before it descends more than a couple millimeters out of the trunion, I release the press, and swap out the punch with the 1cm one. I slide one of my small iron plate with a hole drilled through it for the pin to descend under the shim/barrel/trunnion/pin.
I continue pressing the pin down into the hole I drilled through my 1/4" plate. Once the pin has drifted about 1/4" I put a 5/8" thick iron plate (with a hole drilled through it for the pin) beneath the 1/4" plate, swap out my punch for a 4cm length, and press again. The pin drifts easily at this point, and after a few more millimeters I put a piece of wood under my shims and press the pin down into the wood.
I use increasing long punches throughout this operation, and increase the height of my supporting structure as I go, with the idea of reducing the distance between the presses ram and the pin's pressure point. This eliminates the amount of space for the devil to do his work. I'm sure some people will be glad to know that this method makes it unnecessary to use my well-documented vise and hammer method which also works well, but is a bit more destructive.
Vise Method:
First get an allen-wrench (hex-wrench) that's just smaller in diameter than the pin you're pushing out. Cut off the short part of the wrench and grind it down to 1/4" long. Grind the ends so they're flat with smooth edges. The flat part is important, to prevent the piece from flying off when you apply pressure. Get a washer to use as a cushion between the vise and the trunnion.
Put the washer on one side (the back side) of the trunnion, so it rests on the 45-degree arc cutout that surrounds and protects the barrel-pin. Place the punch you just made on the other side of the trunnion against the pin. Using a bench-vise secure the trunnion with washer and punch as tightly as you can, so the assembly looks like: vise arm, punch, trunnion, washer, and vise arm in that order. Now get your BFH and whack the vise on the side where the punch is. Every time I have done this it easily breaks the pin loose, and pushes it about 1/32" into the hole, and I can easily use the long part of the hex-wrench as a punch to drive it the rest of the way out.
****************
How to Press Out a Barrel Pin
Shop Press Method:
Materials
1) I have several pieces of 1/4" iron that I use in various ways while building. Several have holes drilled through them. Others are dimpled to act as bucking plates.
2) I also have many pieces of hex-wrenches (which is made of the strongest steel imaginable) which I use as punches. I cut hex-wrenches into lengths from 5mm to 1cm and 4cm to 10cm. I used hex wrenches that were (roughly) the same diameter as my barrel pin. To cut these to length I vise them down, and use my circular saw with a grinding blade ($10 at Home Dept) to cut off lengths. The grinding blade is the bomb! It goes through ANY type of steel FAST. Finally I dress up the pieces so their ends are flat. This step is critical. It's what keeps the punches from flying across the room when pressure is applied to them. It is this piece of hex-wrench that I will refer to as a punch.
Method:
I place a 1/4" shim under the rear sight block and lay the barrel/trunnion on the arbor plate of the press. I place my 5mm piece of hex-wrench in the punch position on top of the barrel pin, and lower the press onto the hex-wrench punch. The shim under the sight block keeps the trunnion from rotating, and the very short length of the punch and its flat ends keep it from popping out (usually) when pressure is applied.
Of course the barrel tends to roll forward off the plate until the punch starts to press on it, but after that it no longer is an issue. I always stand behind the side vertical member of the press whenever I use it. I do not wish to have to explain to hospital staff how that piece of steel got embedded in my forehead. As I apply pressure the very short punch will manage the high pressure without having to deal with the very large moment (engineering term) of a long punch. It is the large moment which will cause your punch to snap off of your press and fly across the room. By keeping the punch short I reduce the moment to a manageable one while I pop loose the pin.
This is the critical point. Once the pin is popped loose, and before it descends more than a couple millimeters out of the trunion, I release the press, and swap out the punch with the 1cm one. I slide one of my small iron plate with a hole drilled through it for the pin to descend under the shim/barrel/trunnion/pin.
I continue pressing the pin down into the hole I drilled through my 1/4" plate. Once the pin has drifted about 1/4" I put a 5/8" thick iron plate (with a hole drilled through it for the pin) beneath the 1/4" plate, swap out my punch for a 4cm length, and press again. The pin drifts easily at this point, and after a few more millimeters I put a piece of wood under my shims and press the pin down into the wood.
I use increasing long punches throughout this operation, and increase the height of my supporting structure as I go, with the idea of reducing the distance between the presses ram and the pin's pressure point. This eliminates the amount of space for the devil to do his work. I'm sure some people will be glad to know that this method makes it unnecessary to use my well-documented vise and hammer method which also works well, but is a bit more destructive.
Vise Method:
First get an allen-wrench (hex-wrench) that's just smaller in diameter than the pin you're pushing out. Cut off the short part of the wrench and grind it down to 1/4" long. Grind the ends so they're flat with smooth edges. The flat part is important, to prevent the piece from flying off when you apply pressure. Get a washer to use as a cushion between the vise and the trunnion.
Put the washer on one side (the back side) of the trunnion, so it rests on the 45-degree arc cutout that surrounds and protects the barrel-pin. Place the punch you just made on the other side of the trunnion against the pin. Using a bench-vise secure the trunnion with washer and punch as tightly as you can, so the assembly looks like: vise arm, punch, trunnion, washer, and vise arm in that order. Now get your BFH and whack the vise on the side where the punch is. Every time I have done this it easily breaks the pin loose, and pushes it about 1/32" into the hole, and I can easily use the long part of the hex-wrench as a punch to drive it the rest of the way out.
