A good tool to re-align your bike's derailleur hanger for crisp shifting.

PARTS LIST

1x - 0.75 in Square Aluminum Tube ( 0.125 in thick walls ), about 18 in long
1x - M10 x 1.0 mm thread pitch x 100 mm long partially threaded hex head bolt
1x - M10 x 1.0 mm thread pitch lock nut
2x - M10 flat washers
3x - 0.25 in flat washers
2x - 0.25 in nylon lock nuts
2x - 1/4x20 in x 1.75 in hex head bolts
1x - 1/4x20 in threaded rod x 6 in long
1x - drywall or wood screw, 3/4 in or 1 in long

NO SUPPORTS NEEDED

The holes are designed to not need supports.

There's one place that could benefit from supports (for aesthetics): the 45 degree edge that rises from the bed on DerailleurSide-Hub.stl. (See slicer screenshot)

STRENGTH

More perimeters adds more strength. I used 5 perimeters.

The design has pin-holes cut through sections that require strength. This forces the slicer to create perimeters there. This way you can use lower-infill ( like 20% ) everywhere, but still get strength where needed.

DRILLING HOLES

Insert tube into DerailleurSide-Hub, then use a 10 mm punch, and a 0.25 in punch to mark holes to drill.
Remove the tube to drill the holes.
Drill holes through tube to 10 mm and 0.25 in.
I used a sheet metal drill bit to start the hole, then a 10mm bit to finish it.

It's tempting, but try not to use the plastic to guide the drill bit when you drill the 10mm hole. This will enlarge the plastic hole, and cause the tool to be loose. It will still work fine if you do this, but will not feel as precise.

TWIST THE ROD IN

Because the tool is designed to let you twist the threaded rod to adjust the measurement tip, don't shove the threaded rod into it's "L" shaped holder. Shoving it in acts like a file, and can reduce how well the plastic grips the rod. Instead, just twist it in there.

DESIGN

I wanted the measurement tip to move out-of-the-way easily while maintaining it's measurement. So the hinge is a nice way to achieve that.

I designed this in Fusion 360 with their generous non-commercial license because it's difficult to source bike tools right now.

TO PROTECT YOUR FRAME

To protect your frame, most sharp metal edges have a plastic cover. Print RodEnd.stl to cover–up the sharp rod end. It's not in the photos, but you'll know where it goes.

BIKE

The bike in the model is a Banshee Prime V3.