thud
02-22-2004, 11:52 PM
I have had several requests to show the jigs that I have used to bend a TAPCO flat and to bend the upper side rails. After folding a TAPCO flat, I built some receivers from raw 4130 sheet stock.
This has been an interesting exercise. I am not a tool and die maker nor am I a machinist. I do have access to a rather complete machine shop, so I can play with the machines when I have the opportunity. I am more than a complete novice but much less than a journeyman.
I used the ideas of the Savvy Survivor website to get an initial jig design. I used the same basic concept for both the bottom and side folds. I used cold rolled C-1018 steel for the die and hot rolled C-1018 for the form and the base. I used grade 8 bolts for the guides and I machined guide cylinders from C-1018. The bottom rail jig is quite straight forward and is VERY similar to the Savvy Survivor's. The grey stuff on the jig is a grease (release agent) to reduce friction. Also, that is a 15 inch ruler in the picture.
http://home.earthlink.net/~kono3082/images/Channel forming jig- alt view.JPG
The top rail jig is tapered to match the contour of the receiver and is the exact thickness of the width of the receiver (1.25 inches). That way, I can press through one side and bend metal on the other. The guide on the small end is removable so that I could slide the receiver off the jig, flip, and bend the other side.
http://home.earthlink.net/~kono3082/images/Jig to form upper rails - top view.JPG
IMG]http://home.earthlink.net/~kono3082/images/Jig to form upper rails - side view.JPG[/IMG]
Even after bending, I still had to rehammer all the edges to obtain a nice, square profile. Therefore, I had several pieces of extra steel that I used as various forms.
The other jigs that I created are as follows:
Side dimple jig (mag guide)
http://home.earthlink.net/~kono3082/images/Dimple jig - open view.JPG
http://home.earthlink.net/~kono3082/images/Dimple jig - side view.JPG
Ramp guide for the mag
http://home.earthlink.net/~kono3082/images/Mag ramp jig.JPG
Trigger guard riveting jig. I think this came from silver dollar.
http://home.earthlink.net/~kono3082/images/Trigger guard riveting jig.JPG
This is the result of the whole process. I've built 3 receivers, all very usable, only one of which I shall use at this time. All three have minor flaws, but I tend to be a perfectionist, so I just may build a couple more until I'm satisfied with the final results. I'll probably just salt them away for the moment
Assorted completed receivers, rails, and rail templates (blank on the right is a test piece made from mild steel)
http://home.earthlink.net/~kono3082/images/Assorted receivers and rails.JPG
Completed receiver
http://home.earthlink.net/~kono3082/images/Completed receiver.jpg
Now, for a few comments. If I were to do it over again, I'd use as heavy and as hard a steel as I could get. Most of my C-1018 steel I got locally at a steel distributor. I'd buy more of the stronger stuff from McMaster-Carr (http://www.mcmaster.com/) (that is a great company to deal with). I would use a solid piece of C-1045 1.25 square stock for the main die for the channel forming jig. I'd use 1"x2" steel for the jigs instead of the 3/8"x1 1/2" that I stared with. Where possible, I'd use less welding. Where I had to weld, I'd weld and weld again. Even with the minor stress we put on these jigs, the welds need to be VERY strong.
If you are doing this to save money, don't. Its not worth it. Buy an ACE Arms blank and finish it. If you are doing it for the challenge, go for it. It was fun.
I'd be glad to answer any questions. I'll probalby delete the picture URLs after 3 or 4 months, but if someone wants copies, just e-mail me.
This has been an interesting exercise. I am not a tool and die maker nor am I a machinist. I do have access to a rather complete machine shop, so I can play with the machines when I have the opportunity. I am more than a complete novice but much less than a journeyman.
I used the ideas of the Savvy Survivor website to get an initial jig design. I used the same basic concept for both the bottom and side folds. I used cold rolled C-1018 steel for the die and hot rolled C-1018 for the form and the base. I used grade 8 bolts for the guides and I machined guide cylinders from C-1018. The bottom rail jig is quite straight forward and is VERY similar to the Savvy Survivor's. The grey stuff on the jig is a grease (release agent) to reduce friction. Also, that is a 15 inch ruler in the picture.
http://home.earthlink.net/~kono3082/images/Channel forming jig- alt view.JPG
The top rail jig is tapered to match the contour of the receiver and is the exact thickness of the width of the receiver (1.25 inches). That way, I can press through one side and bend metal on the other. The guide on the small end is removable so that I could slide the receiver off the jig, flip, and bend the other side.
http://home.earthlink.net/~kono3082/images/Jig to form upper rails - top view.JPG
IMG]http://home.earthlink.net/~kono3082/images/Jig to form upper rails - side view.JPG[/IMG]
Even after bending, I still had to rehammer all the edges to obtain a nice, square profile. Therefore, I had several pieces of extra steel that I used as various forms.
The other jigs that I created are as follows:
Side dimple jig (mag guide)
http://home.earthlink.net/~kono3082/images/Dimple jig - open view.JPG
http://home.earthlink.net/~kono3082/images/Dimple jig - side view.JPG
Ramp guide for the mag
http://home.earthlink.net/~kono3082/images/Mag ramp jig.JPG
Trigger guard riveting jig. I think this came from silver dollar.
http://home.earthlink.net/~kono3082/images/Trigger guard riveting jig.JPG
This is the result of the whole process. I've built 3 receivers, all very usable, only one of which I shall use at this time. All three have minor flaws, but I tend to be a perfectionist, so I just may build a couple more until I'm satisfied with the final results. I'll probably just salt them away for the moment
Assorted completed receivers, rails, and rail templates (blank on the right is a test piece made from mild steel)
http://home.earthlink.net/~kono3082/images/Assorted receivers and rails.JPG
Completed receiver
http://home.earthlink.net/~kono3082/images/Completed receiver.jpg
Now, for a few comments. If I were to do it over again, I'd use as heavy and as hard a steel as I could get. Most of my C-1018 steel I got locally at a steel distributor. I'd buy more of the stronger stuff from McMaster-Carr (http://www.mcmaster.com/) (that is a great company to deal with). I would use a solid piece of C-1045 1.25 square stock for the main die for the channel forming jig. I'd use 1"x2" steel for the jigs instead of the 3/8"x1 1/2" that I stared with. Where possible, I'd use less welding. Where I had to weld, I'd weld and weld again. Even with the minor stress we put on these jigs, the welds need to be VERY strong.
If you are doing this to save money, don't. Its not worth it. Buy an ACE Arms blank and finish it. If you are doing it for the challenge, go for it. It was fun.
I'd be glad to answer any questions. I'll probalby delete the picture URLs after 3 or 4 months, but if someone wants copies, just e-mail me.