Hi all. I haven’t been on these forums for some time. No real reason, just the ebb and flow of life and hobbies.
Last time I was on, I was having some major accuracy issues that only got worse. I didn’t always have these issues, and I suspect that they may have even be fixable…but I always knew I built my burly larger than advisable (24x48) so I got this crazy idea in my head to beef up the machine.
I went back and forth between building a primo, trying to strengthen the burly, or doing something completely different. The path I chose is something of a hybrid solution.
For z, I went with a “radial” design, rather than a cantilever. I designed a “sleeve” for the dw660 that allow the unit to slide on 8mm rails and bearing. This is kind of a 3d printer inspired solution.
For x, I went with import clone HGR20 linear slides with a 5mm ball screw. This is the biggest departure. I had to employ a 1:3.75 gear ratio between the stepper and screw in order to preserve torque and this jog speed, as well as go to a single nema 23 motor. This is mounted to a large plywood plate. If this machine pans out, I may cut a rev2 of this plate, and possibly opt for stiffer material. Still, the rails are BEEFY, and lend quite a bit of stiffness here.
For y, I stuck with the mpcnc rollers. I moved the old x rollers to y, where I now employ 4, at the corners of the big plate. I like the torsional stability this provides. Downside is, square is built in…no adjustment. I think I got close, and will improve either by iteration, or skew adjustment in marlin (never messed with it before)
I’m almost at the point of testing. I need to re route and tension belts, address cable management, lower the legs a tad, and add more supports to the log rails (the gantry IS HEAVY)
I hope it all works out. The burly and this community was a hell of a gateway drug. Also, I don’t mean this as an indictment of the mpcnc, I’ve made a ton of cool shit with it! Kinda just taking the next step. If it doesn’t work, I kept all the old pieces intact, or I’ll just build a primo or LR3!
(The table is very messy, might be hard to see what’s going on here)