3DPrinting @lemmy.world Aux @lemmy.world 6 mo. ago

Working 12mm Allen bit, successfully tested to 5Nm

I was doing some bike maintenance today and wanted to disassemble my rear hub. It turned out that I needed a 12mm Allen bit for that, which I don't have. So I 3D printed one! And it worked! Torques safely to 5Nm and I only needed 4Nm for the job. Haven't tested higher torques.

12 comments

Nice! What material?
- PLA
  
  Ha I’m gonna print a flat socket to try my fox air cap
Nice! This got me thinking, is there a telescoping Allen key or socket wrench size determination tool? You slide down the increments until you achieve fit and this tells you what size wrench to fit? I'm guessing the tolerances would be way too tight for 3d printing. I'd keep a tool like this in my garage, I always run and get three socket wrenches from the basement to use in garage and half the time I still misjudge the size.
- I think you are looking for a caliper
  
  A 3d printed caliper is not a bad idea, but the shape isn't always great for working on cars and bikes. A vertical telescope mimics the approach of the tool. Its something trivial enough I would probably never buy it, but might print it.
- I don't think the tolerances would be too bad. A lot of prints that have tight tolerances have a test piece that you print and test against a known object, which let's you adjust your print to get tighter tolerances. Once you correct for the expansion of the plastic, getting the right tolerances should be totally doable.
How do you really know it torqued to 5 Nm? Did you test this on a fixed nut?

I would like to see real yield curves before trusting the torque bales coming off a plastic socket.
- I tested it on a fixed nut to make sure it will fit the the job I had to do. That's all.

You've viewed 12 comments.