Rivet Fabrication Techniques
We use a Riv-Bonding Hybrid technique for fabrication. We use a VHB (Very High Bond) adhesive between the gusset and the tubes. This is used to increase the strength of the joints and reduce the rivets loosening over time.
For more information, here are a couple articles:
A hand roller is best to apply pressure to the gussets to set the 3M VHB tape bond.
Hole drilling
Drilling an accurate hole between gusset and frame is important when riveting. An easy way to accomplish this is to clamp or tape the gusset to the tube, then drill.
I have had good success using "Very High Bond" double stick tape in conjunction pop rivets (e.g 3M VHB Adhesive Transfer Tape 1" Width x 5 Yards Length, .010" Thick. We use it not just as an added strength but as a fixture (stick 'em together, then drill, then rivet -- holds everything in place like a charm).
Here are some clamps that may work: We used Clecos http://www.mcmaster.com/#cleco-style-clamps/=pvbbwvto help hold the sheet metal in place while we were riveting. We also use these for attaching our bumpers onto the chassis during the tournaments.
We have several pairs of Clecos pliers http://www.mcmaster.com/#cleco-style-clamps/=pvbcww
A Cleo is a temporary rivet clamp that clamps through the rivet holes. A cleco is like a miniature toggle bolt. They are used to hold aluminum parts together before permanent rivets are put in.
Most calicoes used here are spring loaded and require special pliers to insert and remove. The pliers hold the body of the cleco and push in on the spring loaded stem in the rear. This causes the latching pins in the front to extend.
Rivet Details
We use a lot of the aluminum 3/16" structural rivets to build superstructure from 1/16" square tube and .090 gusset plate. We use aluminum because drilling out steel rivets is a royal pain, and we never need that strength anyways
Aluminium Rivet 3/16” with a grip length of ¼”.
We use a #10 Drill (.196) for anything 3/16. We found Cobalt Jobber Length #10 bit to work best. In 2017 we will also try a Drill Bit #11 Cobolt Jobber length drill.
There are standard round head rivets. These may require more clearance to the side of the members. There are also Countersunk head rivets don't protrude (on one side, at least). In fact, it looks like a flush-on-both-sides pop rivet is available too.
How to set the rivets correctly can be learned quite easily and should be explained by the designer when he sells drawings or kits to build an aluminum aircraft. The choice of rivets is very simple: only 2017 alloy rivets are commercially readily available (these are the "AD" rivets mentioned in earlier columns). They have good corrosion resistance and are compatible with 2024 and 6061 materials. Series #6 - 3/16(4.8mm) - Hole Drill - .192-.196 (#10 or #9 fall in range)
| The thickness of the material being riveted determines the overall length of the shank of the rivet. As a general rule, the shank of the rivet should extend beyond the material thickness approximately 3/64 inch to 1/8 inch before the stem is pulled. See figure 6-38. | |
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For a crazy detailed explaination of rivets, go hereL http://avstop.com/ac/apgeneral/rivets.html
Knowing the proper size holes and having a good rivet machine is important. A hole chart: http://www.fastenermart.com/html/blindrivet.html
and here are many details on military spec rivet work:
http://www.vansaircraft.com/public/Specs.htm
Best is to use an air riveter:
Here is a video on using this device: https://www.youtube.com/watch?v=G175D8SbvXk
Secondary would be a proper riveter will be long handled :