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Posted: 4/27/2003 2:11:27 PM EDT
| What do I need to rivet my trunnions in? I have all the rivets. Tool?? Tools?? |
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you need an air chisel...available at harbor freight for $20-25. cut your air pressure back and throttle the chisel down so that the hammer strokes are slow. at mscsupply or mcmastercarr you can buy rivet setting tools that will mount to your air chisel. to save a few bucks, you can modify the chisels that come with your pneumatic air chisel by cutting off the chisel end of the tool and using a ball mill to put a divot (same size as your rivet head and slightly less shallow than your rivet heads) in the shank of the tool. to buck up the backside of the rivets you simply need an assortment of scrap steel blocks (preferrably 4140 p.h.t. steel) to take up the gap behind the rivet...and with enogh clearance to allow head formation. |
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The rear trunnion is the easy as you only need a hydraulic press since the rivet goes through the receiver completely. All you need is a bottom plate that has a small concave cup into it that matches the shape of the rivet head you want to form. Drill the open end of the rivet slight to help the forming process and press it into this cup in the bottom plate. The barrel trunnion, however, is a different story. It is not easy by any stretch of the imagination. This is because the four rivets that terminate inside the barrel slieve. There are two recessed bands inside of this slieve. The rivet heads must be formed inside of these bands completely as to not obstruct the barrel when pressed in. Tough to do as this is a very tight area. It is hard to use a hand bucking bar effectively. Working on the rivets is the most difficult aspect of building your own out of a parts kit, IMO. This includes removing the old rivets. Most say to drill them out but you will read about fail attempts cause either by a wandering drill bit (usually the rear trunnion), or drilling into the barrel. Most of these parts kits have trunnions that are not hardened well at all. A HSS drill bit can easily drill through. Finally, the most important aspect on building an AK is to be careful of the advice you receive. I've found that many posters information lacks the key info that leads me to believe that they have not built but are just reading and passing on. Things get lost in the translation or the pass. There are a few who are very consistent with their info. Get to know who these are. Quaterbore probably has the best approach which is post on several boards and sift through the info (rather home in on the best advice). |
| I just made a rivet jig that really is no more than a simple anvil affair out of a piece of 4"x8"flat iron 5/8 thick and another one 2"x4" and a piece of bar stock 13/16th 2" long.First I welded the 2"x4" piece in the middle of the bigger flat on edge then cetered the bar stock on top of the 2" peice the long way for support then put a little blob of weld about 3/4" back from the edge so it will set up in the milled out slots inside the truion. Works great. Did the riveting on the trunion in about ten minutes with a hammer and a rivet set made out of air chisel attachment. |
I don't mean to split hairs, but you didn't make a jig, you made a bucking bar. Just a tip, it's a good idea to polish the surface of the bucking bar that the rivet shank will be pressed against in order to create a uniform shop head. Another tip: after center punching the surface of the rivet you remove, start with a smaller bit (preferably a #40). Drill about 1/16th below the flush surface. Change your bit to the appropriate size hole and ream the pilot hole. Take a pin punch of the same size as the bit and gently pop the head off. Support the underside of the work area with a wood block, or something equally sturdy and punch the rivet through. You shouldn't have to kill it to get it out. If it's not coming out, drill a little deeper and try again. The aforementioned method aleviates the probability of elongating the hole. **One important point to remember** - If you are drilling out steel rivets, use slow speed & heavy feed. If you go full power you're just gonna destroy your drill bit (work harden). I hope this helps. 
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I apologize if I made it seem overly complicated. Riveting is not. I just know from my profession what some of the "gotchas" are. I recommend doing a net search on "how to rivet" and you'll be able to see pictures of the process. Either that or you could do what I did and see you're local Air Force recruiter. LOL! |
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The barrel trunnion, however, is a different story. It is not easy by any stretch of the imagination. This is because the four rivets that terminate inside the barrel slieve. There are two recessed bands inside of this slieve. The rivet heads must be formed inside of these bands completely as to not obstruct the barrel when pressed in. Tough to do as this is a very tight area. It is hard to use a hand bucking bar effectively. i have used a 2-piece bucking bar to set the four rivits that are inline with the bbl., but find that using rivits that are longer than standard length that use the already pressed in place bbl. as the bucking bar is far easier and just as secure. |
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