Somewhere along the way, someone realized you could use these sprues to hold parts in a frame, and a while later the plastic model was invented. Your part would come out of the mold with sprues and flash that had to be removed.

There is lots of opportunity for creativity here.For a hundred years or thereabouts, if you made something out of plastic, you used a mold. And especially how to hook up the printed sections to purchased set track. Like how to make sure the DIY springs don't go walkabout. Lots of fussy little details to work out. A dab of paint would help conceal the hardware.Īll of the above are just a bare-bones concept of a system. If not, then flat-head self-tapping screws should fasten things securely. An alternate method would be to print bow-tie joiners that fit into pockets in the top surface of the track. How to hold the track sections firmly together? Well, zip ties certainly should work, but they require access to the underside of the track. Can be achieved with a simple angled fold in the tape. Solution: Offset the tape once it is on the underside of the track so the pins do not have to be in line. Now if you want to fold the copper tape over the end of the track section you don't have the option of having the pin holes in line with the tape. The pins can be long enough to extend beyond the spring pockets and fit into a second set of holes to restrain the track sections from flexing up and down. Those need pockets in the underside of the track sections to where they can fit between the copper tape and the metal pins.

You can cut the stuff with scissors and fold it over easily to make DIY springs. Thin beryllium copper or phosphor bronze sheet makes excellent springs. So you need separate springs to make the contact. Copper tape has no spring properties whatsoever, and plastic does not work well as a spring long term. The problem is that you need some kind of spring to assure good, durable electrical contact between the pins and the tape. My first thought was to use metal pins to line up the track sections and also act as power conductors. Not to disrespect racerunner in any way, but I think this could be done simpler.

3d printed v slot that lock together