Braze-On Light Mount

Problem Solvers Braze-On Light Mount (http://problemsolversbike.com/products/braze_on_light_mount) adapted for 3D printing.

Ideal for sticking a light anywhere you have a braze-on on your frame. Has to be a standard 4 mm threading. Would be great for the midblade fork braze-ons on a ton of Surly forks.

How I Designed This

http://problemsolversbike.com/products/braze_on_light_mount General dimensions came from here. I had to guess for a lot of it, but it's probably okay.

For the cylinder ID, I did a 6 mm offset from the OD, so that gives a 32 - 6 = 26 mm ID. The mating faces of the end caps were designed with a radius of (32-3)/2-1, so a 27 mm ID, plus a 1 mm by 1 mm 45 degree chamfer to better tolerate the fitting. The inside of the cylinder has a 45 deg chamfer on both ends as a transition between the 32 mm OD & the 26 mm ID, again to better tolerate the fit.

I hope it works.

I measured the OD of a random 4 mm socket head bolt I had lying around: 8.90 mm, so 115% of that is about 10.22 mm, which became the inset on the end of the end cap to sink the head. The head was 5.09 mm tall, but I tried to keep the cap relatively short, so I cut it from the end to the 2.5 mm from the inside face, giving about a total of 5.34 mm of sinking height. It should shelter most 4 mm socket bolt heads below the outside edge.

Assembly & Materials

See the Problem Solvers website linked above for instructions.

Reverse the end cap to change the effective length of mount as necessary.

You'll need a very long 4 mm bolt.

Print all three pieces: cylinder, reversible end cap, end cap.

Category: DIY