3D Brake Pivot Jig Mk 2

*** Anyone wondering what the hell this is all about should go back one post***

Another night, another brake pivot jig. I'm getting better with Inventor; I made all this from scratch in less than 2.5 hours, and even worked on some actual schoolwork during that time.

• Distance between pivots is adjustable from 2.25" to 3.5" IIRC...2.5" is stock width for Dia-Compe centerpulls.
• All indexing slots are 1/4". All hardware is M6, colored gold for jig bling. The brake pivots are included now, colored gray.
• The Backbone Bar is now 1/2" x 3/4" steel. It's 15" long in this rendering, but that's subject to change.
• This design is more complicated and requires more milling, but it was designed to solve a few problems inherent in the last one. Those problems are described here and here.
• I am thinking of using steel for everything, but alu could be used judiciously.
• As drawn, this can be made from the following:
- about 18" of 1/2" x 3/4", in two pieces
- enough 3/4" round for the dummy axle(s)
- a few inches of 3/4" square
(plus a few inches of 1/2" round for the brake pivots)
• I think it's possible to make revisions such that 3/4" round and 1/2" x 3/4" are the only required sizes for the jig itself.

Assembly top view. Dropouts go on the left side.

"Crotch shot" looking up from the bottom of the fork.

Isometric view from top right of fork.

Isometric detail view. The pivots aren't symmetric, and it's bothering me a little, but I had to upload in a hurry.

Assembly side view.

Isometric dummy axle view. It has two 1/4" wide slots milled into it, then drilled/tapped M6. This would (I'm pretty sure) be compatible with Bringheli jigs.

Top view detail.

Bottom view detail. You can see that the brake pivots are hollow, and showing the gold-colored M6 bolts that holds each of them to the mating piece.

View looking down steerer tube.


Anonymous said...

Drawings are lovely. I only understood the first paragraph of text, however. Maybe that's because I'm the mom.

Anonymous said...

What happens if the brake bosses aren't perpendicular to the seatstays?

Note the rotational option on the Anvil jig: