The only missing parts were some 1/4" washers. I counted out (almost all) of the small parts and was short one 18mm M3 but had an extra 20mm instead. My cheap bolt gage made checking lengths really easy, and I used a glass baking dish (don't do this if your wife is home...) as a parts holder/sorter. The smooth glass made it easy to pick individual small parts out and flick them into different corners while sorting. Sure wish they'd used a few plastic bags rather than one big handful of loose parts.
I ordered just about every spare bit of hardware suggested here (it's 40+ miles round trip to the hardware store), but so far have only used the 6-32 square nuts. Mine are a loose fit in the slots; while they work fine they'll slide out if the part's tilted at all, so keeping them in place has been a challenge at times.
I was going to stain it bright red, but never found the right color locally. I just lightly sanded with 320 grit, spray shellacked it, and started in. Perhaps some rattle can red is in it's future.
For the most part it's gone together without problems. The base parts needed a bit of beveling on the ends of the tabs to get them started - the side plates were a little warped and I had problems both aligning and straighting them while starting the tabs into the deck straight, so a little bit of sanding on the tab corners helped get them started. Getting the X carriage together was a bit frustrating, just couldn't keep the retainer rings in the right place while fitting the bearings into the side pieces was a bit past the limits of my mechanical dexterity (in retrospect a bit of masking tape might have helped), but it's together and kept all it's balls.
I got all LMxUU bearings, but the laser cut slots hold them fine, so they did make them a bit smaller. Since all that's supporting the sides are just the points of the cutouts (maybe could have beveled them a bit, too late now) I expect they'll wear the edges down and settle in when it starts working.
The linear bearings really are crap. The Y axis LM8UUs had one one side that went together and had almost no friction. Of course, that rod slid out (should have used some masking tape to hold them on) while turning the base around, and while carefully putting it back together a couple balls fell out. I must have put them back in a half dozen times and had them come out again before they went zing and disappeared across the room. The spare did the same (but with only one ball coming out), so my Y axis is down a ball. Replacement LME8UUs from vxb will be on order shortly, plus some LM8UUs so I can change the carriage to 4 bearings later. The rods seem to move OK, but now both sides are a bit gritty rather than just one.
The bearing balls really do recirculate in their plastic grooves. I used a miniature slightly magnetized flat screwdriver to carefully open up a gap and push the errant balls back into place, then slid them around a bit in the groove. Unfortunately it wasn't very effective since the little buggers kept jumping back out.
The LM (not E) 12UUs have just enough drag the bridge won't drop by itself, but it moves smoothly and without any gritty feel or binding. 12mm rod alignment is withing the tolerance of my electronic angle gage thingy. I think the gages sides are a tenth of a degree or so out of square (no real way to test), and there's more variation than that (maybe 0.2 or 0.3 degrees) between the sides and deck of the base assembly - I tried checking square from both the top and sides of the base. I'm seeing about 0.1 to 0.3 degrees front/back and side to side, so as delivered it's square within my measuring capabilities.
The cast large herringbone extruder gear initially looked good, but the bolt head recess had some blobs and the bolt doesn't sit straight (now there's a surprise...). Other than that the hobbed bolt head is a "hand tight" fit - it'll go on and off by hand with some pushing, seat fully with a little bit of pull from the nut but still be removable. I've been carving away on the blob with an Xacto knife and and it looks like it's gone, but still haven't got the gear to go on without it's characteristic wobble. I'm about to try some paper shims, then will probably just hope it's good enough. While carving away I thought about taking the CNC router and re-routing the bolt recess, but that's a bit excessive. It looks like it's a bit out of round, too, so mine is as poor as everybody else's. The spacing washer might need a bit of filing, my thinnest has the hob a hair out of alignment. Spur gears will be an early post-calibrated print.
Assuming it works when it's all together (and getting a bit ahead of myself) I plan to enhance CL1's suggestion and hand-write some small gcode files to whomp the axes back and forth for a while and let everything settle in (if it works I'll attach the gcode), then retighten everything and start on calibration. Initial thoughts are to take each axis individually and work them back and forth at increasing speeds and travel until they either obviously miss steps or it starts hopping around the table. After that I'd like to try various combinations of axes with both straight diagonal lines and arcs - not sure that's helpful but it'll be cool to watch - and continue until everything stabilizes or my patience gives out... If anybody's got suggestions for appropriate motions I'd appreciate them.
Time to get back to assembly. Maybe a working bot's in my future after all
I was half expecting Brook to go broke before the final bots got shipped, but (even though there's still time) that's looking a lot less likely. And speaking of big expenditures it looks like the mega-laser cutter's taped shut and they're not using it. Anybody know?Kirk - an almost botted backer
(for worldwide clarity, I mean in the mechanical sense of the word *jerk*.)
. I'd be interested in knowing if upping the speed really does anything, if the speeds/accelerations are reasonable, and if actually does anything useful.
or I would have used that instead. Insulation is currently a piece of cardboard held with the bulldog clips; when I dig out the neoprene pipe insulation I'll add a layer of that to the cardboard.
to cover them - keep me from looking like the little light bulb
That's electronics...), but they were all out of the geared extruder beta by then. I signed up for the waitlist, recently got an email it was back in stock, and ordered one. They shipped it within two hours ( ! ) of placing the order, and the dogsled brought it through the howling arctic blasts to the Moosecave. Only the metal parts were included, along with links to stl files to print the body. Here's the saga.