Tube Miter Software

Giles Puckett wrote a nice little windows app some years ago called tubemiter that will plot out a curve on a piece of paper that you then wrap around a tube to act as a cutting guide. This is a great idea, only his application is limited because A) it doesn't allow for tubes that meet with an offset (i.e. the center axis of the two cylinders don't intersect). And B) it only prints the end miter, it's up to you to figure out how to align it.

I'd like to extend his application by adding more reference lines, an offset parameter, and possibly even the ability to put multiple miters on a single printout to minimize compounding errors from measurement. If I could plot out both my headtube and BB intersections, and print it on an 11x17 piece of paper, that would be awesome.

Instead of using a standalone windows application, I decided that the best bang for the buck would come by writing a script for my favored CAD program, DeltaCad. By using a CAD program rather than a standalone app, I can dimension and draw in other references as needed. I can also plot multiple intersections and cut and paste them onto my final drawing. The only drawback to this approach is that the macro runner is a bit flaky when run out of wine under linux, such is life I suppose.

I should point out that modifying the script to work with elliptical tubing would be pretty trivial. If anyone is interested I'd be happy to make the changes.

You can download a demo copy of DeltaCad from the website, and a copy of my script here. To run it, go to the macro tab. Click "Edit macro list" and add the tubemiter file to the list. Then select it from the pulldown and select run macro.