Gunco Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
3,518 Posts
Discussion Starter · #1 · (Edited)
Im ready to do some center supports on my flats I have bent. Everything is fitted and ready except for the rails. I was going to line up the rails and then c-clamp them in first, then check with the bolt and piston for fit. Once that is done I want to drill a spot for the rivit head to sit into a piece of cold steel and then press the other side of the rivit head. Then, once I purchase the spot welder, Ill be done.

Oh, Im using tapco's center support rivit and bushing.

Can this be done this way using the press? Would give a flat end on the one side. Opposite of the selecter lever. Well, the one end is kind of flat rivit head.

Any suggestions would be helpful. I was going to attempt this on tuesday. My day off! YAY!
 

·
Registered
Joined
·
3,518 Posts
Discussion Starter · #2 ·
Any suggestions would be helpful.
 

·
Happy Camper
Joined
·
7,794 Posts

·
Registered
Joined
·
2,071 Posts
I would be very careful with Tapco's center support bushing and rivet. I have been down this route a few times, and still haven't found a method that I like the best. I know a lot of the old timers around here make their own center support, by using a piece of round steel and cutting it to length, then rifle drilling it. There are so many different ways to approach this one.

I used a Tapco rivet on one of my -63's and after doing exactly what you mentioned, with a flat piece of steel and using a ball end mill to drill out a hole in it, smashed the tail of the rivet with a press. 3 out of the 4 times, the rivet would buckle over and bend on the outside of the receiver. I'm sure this could be accounted to operator error. However, when smashing the rear long rivets, they did come up short after smashing. In fact, my 2 rear rivets that went through the rear trunnion just barely expanded enough to fill the hole that I drilled for the rivet. I ended up having to use the mig welder and drop a couple of beads over the heads of the rivets. This kept the receiver from popping over the smashed end of the rivet. I ended up using some of 1-pat's group buy rivets which are a lot longer and could be cut to length and then smashed.

So, if I had to do it again, I would try to use a longer rivet, if I was to use on in the center support. I had a helluva time getting the rails, holes, rivets, and center support all together and then smashing the tail of the rivet and having it smash nicely. My next gun, I will probably buy a long piece of steel and cut it to length and either weld it in or tap one of the ends and use some sort of bolt on the outside. Welding will probably look nicer though.

Last, if you make a mistake with the rivet and Tapco center support bushing, while smashing you will be up the creek. It is a royal PITA trying to remove not only a rivet, but a rivet with a bushing around it in the middle of the receiver. My screw ups took quite a bit of time and finish off the outside of the receiver. Good luck!
 

·
Registered
Joined
·
3,518 Posts
Discussion Starter · #5 ·
hcpookie said:
You're saying do it before the rails are welded? I've always done the center support AFTER the rails, so I can't be sure this would work. Assuming everything lines up you should be OK.

I've put what I know about the center support here:

http://pookieweb.dyndns.org:61129/AK/docs/construction/center_support/center_support.htm
When smashing the flat end of the rivit did you use a flat piece of steel with a dimple in it? Or just a flat piece against it? I couldnt tell from the pics.
 

·
Happy Camper
Joined
·
7,794 Posts
I smashed both sides flat.

I too had the "bending" problem with the rivets. It's my conclusion that the metal is the problem. I've used the 3/16" rivets from McMaster-Carr on my AK-103 build (Krink side-folder rear trunion) and had very easy rivet smashing:

http://pookieweb.dyndns.org:61129/AK/rear_done/rear_done.htm

... note my "sophisticated" rivet squeezer! ;)

The 1-Pat GB rivets want to bend before they smash. They are longer than the 3/16" rivets. Also, if they are off-center from the direction of the force, they will bend, guaranteed.

Not sure how to correct for this. A shorter rivet is the first consideration. Maybe a softer rivet too... high heat and slow cooling would normalize the metal and make it slightly softer, but not by much. I'm also thinking I could use my bolt cutter rivet squeezer to more accurately apply the force, but not sure how best to go about it. More practice won't hurt, either.
 

·
Registered
Joined
·
3,518 Posts
Discussion Starter · #7 ·
hcpookie said:
I smashed both sides flat.

I too had the "bending" problem with the rivets. It's my conclusion that the metal is the problem. I've used the 3/16" rivets from McMaster-Carr on my AK-103 build (Krink side-folder rear trunion) and had very easy rivet smashing:

http://pookieweb.dyndns.org:61129/AK/rear_done/rear_done.htm

... note my "sophisticated" rivet squeezer! ;)

The 1-Pat GB rivets want to bend before they smash. They are longer than the 3/16" rivets. Also, if they are off-center from the direction of the force, they will bend, guaranteed.

Not sure how to correct for this. A shorter rivet is the first consideration. Maybe a softer rivet too... high heat and slow cooling would normalize the metal and make it slightly softer, but not by much. I'm also thinking I could use my bolt cutter rivet squeezer to more accurately apply the force, but not sure how best to go about it. More practice won't hurt, either.
Thank you for the tip hcpookie. I am going back to HF tomorrow to get a 5"c-clamp. Im going to try that method of crushing the rivit. It looks really simple and cheap.
 

·
Registered
Joined
·
286 Posts
Yosuthnmasa
I am putting together one of Tapco's AK flats and am having lousy luck getting the center support rivet to do what I want. I was searching through all of the back threads about this procedure and found this thread where you said you were having a very similar problem. I started with support tubes from Scott at DPH, I opened them up about .015" so they would accept one of the long rivets from 1-Pat's group buy. When I went to press the rivet two things happened, 1) instead of squashing down and forming a fat round tail it kind of leaned over and came out like crap and 2) the tube and rivet bent before it made anything that resembled a decent tail. At this point I am thinking that something in the way of a softer rivet and a beefier tube are in order. The outside of the support tube is right at .245" and the inner is about .177 which gives me a wall of around .035". Maybe if I went with a little beefier tube, a skinnier rivet, and some kind of brace on the inside to support it while I put the squeeze on it. At any rate, if you would, please let me know what you did to rectify your situation.
 

·
Registered
Joined
·
1,856 Posts
Since the center support rivet isn't load bearing (unlike the front or rear trunnion rivets), I heat the end (1/4" or so) red hot and let it cool slowly. To support the preformed rivet head I use a piece of .250"x1"x2" flat stock with a small reccess milled into it. Then assemble everything together. The non-formed part of the rivet will stick out from the receiver (LH side). I then use a hammer to start the rivet head so that it doesn't bend over. I use light tapping to start the head. Once the head is formed I use the press to finish the job. Also the only center support tube I use are the ones that K-VAR sells (beefy). Never had any problem with that tube collapsing.

Plinker has come out with a new (smaller) rear trunnion riveter ($40) that will do the center support rivet also. It uses an alignment pin so that when you use the press, the head forming pin is in alignment with the rivet so you get an even crush. I haven't used it yet but it looks like it will eliminate the rivet from bending over.
 

·
Registered
Joined
·
2,071 Posts
Basically, I had the very same thing happen when I used the Tapco rivet and bushing in a press. What I found, in many occasions, was the head bending way over on the outside of the receiver, or like you said, it would bend the bushing and rivet in the inside of the receiver(Not a lot, but enough to matter). I also had problems with the rivets from Tapco when I used them on the rear trunnion. After pressing, the head would barely form. In one instance, the head didn't squeeze out enough to fill the hole that the rivet went through. So, I had to drop a weld on the head of the rivet to keep it from popping out.

I also tried the route you went. I got some of 1-pats group buy rivets(which are to wide for the Tapco center support bushing) and put them in my drill press and filed the overall diameter down so that it would slide through the bushing. Then I went at it again, with the exact same problems as before, bent tails. Last resort....went to Lowes or home depot and got a
"bushing" looking thing that was similar to Tapco's, but it was quite a bit thicker. Then I used one of 1-pats rivets in it, cut it a bit shorter and then got a piece of round steel(about an inch in diameter) and started pounding the tail of the rivet(I also used just the head of the hammer in the beginning). I set the receiver on the flat part of the vice and tried to hold it as level as possible. If you don't the rivet head will slowly bend to one side forcing you to hammer more heavily to one side to fix the problem. The head actually formed really nicely. Then I took a bolt with a rounded head(like a cap head) and hammered the head of the bolt against the tail of the rivet around the edges next to the receiver to make a rounder head. I'm sure there are other methods to make a nice looking head. My only problem with this method, is the marrring that can take place around the tail of the rivet as you form the head. Doing it my way, left dings and it visually wasn't as nice as I wanted it. But, using a hammer with quick jarrring blows, expanded the rivet and the head as well as filling out the gap in the bushing from Lowes. You also have to make sure and pound it hard enough so that it gets to the point of expanding in the bushing and forming a head. If you dont the rivet might be loose in the hole and bushing. This is basically what i did.

So like you suggested, a beafier bushing, and/or better rivet. Supports? Havent seen any of them yet?
 

·
Premium Member
Joined
·
6,900 Posts
I also had terrible luck trying to rivet the center support, so I have been making my own bolt in ones.
I saw plinker's new jig and ordered one, when I receive it, I will go back and attempt riveting again.
 
1 - 11 of 11 Posts
Top