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Staying a step ahead and looking into ordering the rivets for .025 rib stiffeners I made. MS20470AD3 is the number. How do I know the length to buy?
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Rivet diameters are specified in 32nds of an inch, Rivet lengths are specified in 16ths of an inch.Originally posted by augman40 View Post
The needed rivet length will be the thickness of your material + 1.5 multiplied times the rivet diameter (to get the proper diameter shop head once it is driven) For example an MS470AD3 is 3/32 diameter so to rivet two thicknesses of .025 material your total rivet length would be ((.025+.025)+((1.5*3/32)) =.0190625 to get your rivet length in 16ths of an inch you can multiply by 16 to get 3.05. Since the closest rivet lengths you can get would be either a 3 or a 3.5 you can round to the closest which would be rounding down to a -3 rivet so for the purposes of this exercise the rivet needed would be a MS20470AD3-3. I have been told by several people that you are better off rounding down than by rounding up but I recommend reading up on it and coming to your own conclusions.
Alternately you can purchase rivets that are slightly long and go through and trim each to the exact needed length with a rivet shaver.
My approach was to go through and study each page of the plans, figure out the material thicknesses I will be riveting together and the size of rivet needed, put them into an excel spreadsheet and calculate the lengths needed based on an equation in excel.
Hope this helps,
BillLast edited by Redneckmech; 01-27-2023, 11:25 PM.-
Point taken, I will include it in my future references. All too often I revert to my day job where I need to simply tell someone how to do something rather than giving them the information to figure it out for themselves. Any mention of best practices for riveting would be remiss without either it or reference to mil-r-47196a.Last edited by Redneckmech; 01-28-2023, 11:56 AM.
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Don.t scrimp on buying rivets. With that being said, someone on this sight counted all the rivets to rivet a wing and converted it to pounds of each rivet. The Patrol Quick Build area has a Hardware list, and rivets for a wing are included there.
With that being said, I've found that the cost of shipping outweighs the cost of rivets. Buy 1.5 or 2x number of what you need and buy every size you can of the shorter lengths below -5. Get length half sizes, like -3.5, and -4.5's.
I found that cutting rivets to length with a rivet cutter is futal. My tool workhardens the rivet and I get ppor quality effects when the tooling smashes down the rivet stem into the shop head. A nice fresh soft un-adulterated rivet stem of the proper length FOR ME and my skill level is required to get outstanding results and if you buy them all at once cost is minimal.Brooks Cone
Southeast Michigan
Patrol #303, Kit buildComment
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augman40, Start with AC 43.13. if you are viewing the PDF, the section on rivets starts on page 156.
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Another view on rivet removal.
I have no rivet removal tool. I don't want one. I use a drill and bit the same size I used to drill the rivet hole. You can get very good at removing rivets in no time. Drilling is quick and easy and My confidence at removing rivets is quite high because I've done it so much. In my 7 years of doing this I think I enlarged one hole out of several thousand. So, Just center-punch the rivet head, and as you drill make the drill bit stay in the center of the rivet....easy to see it drift. The drill may even be on a 30 degree angle for a few turns to compensate for the drift to make it stay centered on the rivet head. When you think your hole is deep enough into the rivet head try to pop the head off. if your not deep enough it wont pop off, no harm done. Drill a bit more and try again.
BTW, a dull drill bit will drift. If you don't sharpen your bits like me, buy the Colbalt Jobber bits by the dozen at Pan American Tools. These are industry best standard bits and every one is marked with its size so organizing them is a cinch. Get some long ones while your at it....again think shipping. A dozen of each size bit is about right.Brooks Cone
Southeast Michigan
Patrol #303, Kit buildComment
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I agree with Brooks on this, I bought one of the removal tools early on but get a quicker and nicer job without it.Comment
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The first few times I had to drill out a rivet it was a bit stressful, but now it's no big deal. With a little experience you get pretty good at "steering" the bit through the middle of the rivet.Comment
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SJT, don't take offense as I'm not picking on you as I'm intrigued by your statement and confused why "we all end up doing something like desertbearhawk in the end." Let me try to help as it's either the gun or technique. An old IA helped me when I first started as an A&P and what I share is not original to me but what he shared that really works.Originally posted by sjt View Post
I've used a rivet cutter like that for thousands of rivets without issue when I was doing A&P work. If you are having a problem with sheared rivets using a rivet cutting tool like pictured above (not a pair of wire cutter/dikes) I'm guessing it's one of three things: a gun with poor speed control, a finger with poor speed control, or too much air pressure. I watched that video in SJTs post and I shake my head. That's way too much work for cutting a rivet,. Let me help you use that tool and save you a lot of time and effort.
Besides the usual "Keep the gun perpendicular and lightly but firmly pushed into your work and the bucking bar flat to the work (sure, everyone knows that)" here's the key with a cut rivet from a rivet cutting tool. Start very slow on the first 3-4 hits so the not-as-perfectly-flat sheared end of the rivet gets flattened in those 3-4 hits. Once it's perfectly flat from the 3-4 hits I speed the gun up until I have the flattened height I desire then stop and inspect. I can see having problems with cut rivets if you just pull the trigger full on and let-r rip because any angle on the cut will throw the bucking bar off at an angle and once the bucking bar is out of kilter then get the drill. Use the 3-4 slow hits to flatten the end then you can speed up to finish. Dit dit dit dit brrrrrrrr constantly speeding up until done.
For a demonstration, look at https://youtu.be/37SQj_WMnPA?t=946 and that's the speed (where he hits the table) that I use for the first 3-4 hits. He also demonstrates good speed control constantly speeding up at 17:00 minutes in https://youtu.be/37SQj_WMnPA?t=1020 I do a combination of both those parts of the video by putting them together: I give 3-4 really slow hits to get the sheared end flat, then speed up consistently until done. He does similar in this clip but I don't give it quite as many slow hits but you get the idea https://youtu.be/37SQj_WMnPA?t=1300 Give that a try and I think you'll be pleasantly surprised with all your rivets.
Perhaps your rivet gun doesn't have good slow speed (some are very bad) or you might have the air pressure too high so the gun always runs fast and hard. I have used guns that don't have good speed control and for that I can see problems but the problem lies in the gun or the trigger finger, not the sheared/cut rivet. I have an ingersol rand gun that was bought from Boeing surplus that has great speed control and is the nicest running gun I've ever used. When I was in A&P school you learned which guns you could really control the slow speed and which ones didn't and if they didn't I didn't use them. It was funny too when guys ran too much air pressure and would always have problems over-driving rivets, bending the piece (especially with flush rivets) or not being able to control the gun and bar well making smileys on the rivet head or worse yet on the piece. Some folks also think of the trigger like an on/off switch and not like a rheostat/fully adjustable. Think a variable speed drill trigger and not on/off.
I think if you try this technique you will find a rivet cutter is a handy tool. If you use this technique on all rivets you will find you can be really consistent because you have good speed control and things don't get away from you. In my experience a slower gun is faster work and a fast gun is slower work because you end up drilling out rivets and redoing them or worse yet replacing aluminum pieces.
I hope that is beneficial for someone who is having problems with riveting in general but especially with cut rivets.
Lastly, I have never needed a tool for drilling rivets other than a spring loaded center punch if the dimple is faint, a drill with the proper size bit and a punch with a squared off point to break off the drilled rivet head.
JayLast edited by JayDub; 01-30-2023, 10:40 AM.BH 4 place plans #767, currently finishing a Kolb Firestar 2 kit. Very interested in the BH LSA.Comment
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I appreciate the advice; I am certainly willing to try it again because I want the rivet gun to be the goto tool for building.
In another thread I was trying to make the case for only using a rivet gun while building. I wanted someone building an airplane to be able to do it with the minimum expanse of tools.
Admittedly, I am not the person to make the case since I buy tools at the drop of anyone's hat. I even thought I would start a thread on all the tools that were truly a waist of money.
It is possible to get AD3 and AD4 in half sizes; not so with the AD5
My frustration with a rivet cutter may involve a C-frame with a 1/2 drill rod backset. I have wondered about the physics of what goes wrong.
The choices for AD5 rivets is limited. The additional force used to cut the rivet probably does not help making a square cut.
I thought maybe the shaft wobbles between impacts. Also, a very long shaft used in the backset does not lend itself to keeping absolutely square.
Also, the additional weight of the drill rod requires a minimum of a 4x rivet gun set with a harder hit then without the drill rod.
In the end I just put a lot of effort in making square cut rivets so I did not have to think about it.
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The rivet removal tool is only $40 from yardstore.com. In terms of spending money on things I could do without it does not come close. I can just leave it chucked up in one of my air drills. I have an air drill for each numbered bit so I do not have to change them out.
Stan
Austin TxComment
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