Doing the Jig!

After a brief hiatus for spring break, I have resumed work on the bike.

Building the frame jig was my priority. I made the frame jig using 30-series aluminum extrusion from Misumi. This extrusion is affordable and accurately cut to length by Misumi before shipping. The frame jig has two small vertical extrusions that hold the threaded rod front/rear axles. I created 3D printed drilling jigs with a steel guide bushing to drill the threaded rod holes. These jigs proved to be very accurate.

The frame jig also uses multiple 3D printed supports (in purple/yellow), which will hold various frame parts. There is a bottom bracket support, a steerer tube support, and multiple supports for the cargo area frame rails.

I then cut the headtube and downtube off the donor frame and carefully ground the welds off the bottom bracket shell. I ground off a little too much material near the bottom bracket’s driver-side edge, but this shouldn’t be a problem during welding/riding. I then used a 3D printed jig to notch the top tube to accept the steerer tube.

Finally, I used a combination of 3D printed jigs and stencils to create the base frame rail. This rail attaches to the steerer tube and the bottom bracket shell. Currently, the base frame rail and steerer tube are almost perpendicular. I still need to grind a little more metal but am please with my current progress.

I just ordered a dry-cut metal saw ($159 from Home Depot!) and hope to have the rest of my frame rails completed sometime next week. Thank you for reading!