Originally Posted by lr172
Not sure what is happening here, but I believe that the shop head should be made by the material making a nice 180* turn, with the end of the rivet, after the 180, touching the backing plate. In your picture of the "Good" rivet," your material just makes a little tulip, with no contact. I would be concerned with these loosening over time.
Not an expert here, but I believe this type of rivet requires the full turn with the end of the rivet material pressed against the backing material. Take a look at a picture of a manufactured brake pad. It achieves it's objective very differently than a solid rivet. It is a lot more like a formed grommet.
The rivets labeled good, are not
Either the tool that is being used, or the technique being used is suspect.
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Van's Aircraft Engineering Prototype Shop Manager
RV-6A (aka "Junkyard Special ")