Monday, August 4, 2008

Stepper circa 1993

Had a good day shopping at garage sales, there was a community sale where you didn't need to drive very far between stops. I bought a Twain flatbed scanner that has a good 1.8 degree stepper motor, and a base with side rails about 19 1/2 inches (500 mm), the stepper moved a belt that was hooked to the carriage after looping around a geared belt idler. The carriage had a lot of torsional slop though, it only has one horizontal keeper bearing on one side, and the other side has two, forming a triangle, but they are both on leaf springs, so it's free to twist. It'll probably be better to build a carriage than to re-purpose the old one. The stepper has a reducer gear hooked right to the mounting bracket, if I can figure out a way to mount the output gear to a threaded rod it would have very good resolution, there is very little slop in the gears, you can feel the slop a bit by touch, but it isn't visible enough to measure. The scanner also had a power supply that has 5v 2A, 15v 1.5A, +12v 0.3A, -12 0.3A, it's probably good enough to power a few more motors, and it's dead quiet, and slim-lined along the side of the case. This stepper was run from another ULN 2003A Darlington array, though it's a six wire stepper, so it should run from the Stepper Motor Driver 1.1.

Also got a nice shelving unit, so the giant pile of junk in the center of the garage is starting to get a bit smaller as I organize everything, hopefully it will soon all look like I meant it to be that way. It took a while to re-assemble the shelving because of the gravel floor, so it needed attached to the wall despite being a free standing shelf. Plus there was stuff in the way, but now most of that is on the shelves.

And I got a router table, once I get my router hooked to that it'll be a lot easier to build a RepStrap.

And I found some sort of lathe looking thing, If I can figure a way to attach a chuck I'll be able to make the non-printable extruder parts.

Later I salvaged some bearings from a set of inline skates, (14 of them, 2 are bad). The skates are from Goodwill, they had a large pile of skates.

Total cost of RepRap related stuff was $11, though the router table and shelf ran another $20.

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