Filament Riveting Tool

thingiverse

For my latest project, I utilized a short piece of filament for the pins in the hinges at https://www.thingiverse.com/thing:2754147. To secure them properly, I employed a hot air gun to heat up the blade of a knife until it was extremely hot. Then, I pressed the side of the blade onto the end of the filament and melted it until its diameter increased by about 50% compared to its original outer diameter. This approach worked functionally, but I didn't appreciate the flat end and sharp edge that resulted. So, I decided to create a tool with one purpose: forming a button or rivet head on the end of 1.75mm filament. I began with a long #10-32 bolt – specifically, the type featuring a blank shoulder area. Typically, screws longer than 2" have approximately 1" worth of threads and the rest is non-threaded shoulder. A #10 screw boasts a body diameter of 0.188". I cut off the head and drilled into the blank end with a 0.110" drill, about 0.020" deep. The resulting cavity was a cylinder created by the drill measuring 0.110" in diameter by 0.020" long, plus the point of the drill. Next, I drilled a 0.161" (#20) hole into the end of a 5/8" diameter wood dowel and screwed the bit firmly into the dowel. To minimize damage to the tool bit, I opted for using wood instead of printing a plastic handle because it would melt when heated with a hot air gun. To form a rivet head, I heat the tool bit with a hot air gun until it's extremely hot. Then, while still hot, press on the end of the filament until it fills the cavity perfectly. This results in a beautifully formed rivet head (picture 3).