Mooselake
|
 |
« Reply #3 on: November 22, 2017, 11:08:17 AM » |
|
Sorry to take so long to get back, been having some recent medical adventure s that seem to be working out fine, subject to the perpetual "just another test" they like so well. As a sort of electrica l engineer (degree, but became a programme r) the problem is, of course, electrica l in nature and was fixed with the equivalen t of sticking my fingers in an outlet.
This machine is quite slow, I was assuming that any positioni ng error would be sorted out by the encoders and the several PID algorithm s (besides speed and position the cutting head is also a pendulum, although there's a several new linkage designs to solve that) that I don't understan d very well. If that were true (sounds like it's not...) then accelerat ing from a stop would sort itself out, while stopping, at least at higher speeds, would require planning. Sorta like the early no-acceleration. no planning, always full stop MCU controlle rs. I see I need to do some more research. ..
It's driven by two chains in the top corners, brushed DC motors with encoders, and a worm drive gearbox to hold position when not powered. Top calculate d speed is around 40 inches/minute, the practical limit is currently around 25. A complete 4' x 8' (think that's about 1.2 x 2.4 meters, but it's a standard plywood sheet) machine is right around $500 US including the router. More if you pay small lumber yard prices for 3/4 ACX like I do, but still under $600. In my case it's hanging on a wall waiting for the build a shop project (including hauling off around 700 drywall buckets worth of sand, dirt, and a lot of round glacially tumbled rocks). Found another concrete floor 8 inches under the broken up one that I was removing, adding a lot more work but giving a much better surface to build the new wood floor up from. Like all Mooselake projects it's taking far longer than planned.
Kirk
|