Decided to build CNC for cutting full sheets of plywood mainly (because any CNC does it better than I do ) thus the size. 2500mmx1250mm working area.
Milled ALU side plates (I apologize for not ordering from Ryan, overseas shipping costs an arm and a leg).
Printed all parts using my old slow Ender 3. All tubes are heavy 25x3mm steel ones. After a bit of thinking I’ve decided to connect both sides of the CNC above X gantry to make most of the wiring fixed (the only ones which move are X axis and 220v). Firmware is pretty much unchanged, only adjusted drivers setting, current and Zmax and inversed few steppers settings using firmware config because for me it was easier than redoing connectors etc.
Hit the issue with failing Z-axis and very hot drivers (TMC2225) so printed custom box which looks ugly but includes fan for cooling and soldered in 1k resistors for endstops. Box should be redone (as well as ad-hoc plywood cable channel holder but I’ve got laser cutter and it was Quick&Dirty way of prototyping)
and cable management needs some love but in general… It works!
First cut (not counting endless number of “air cuts”) done today LowRider v3 first cut - YouTube and safe settings look too … safe
Of course first issue appeared. Apparently I got “ramp” setting of Fusion 360 wrong which leads to way too deep cut (ramp distance + material thickness) as the result ply was cut through without holding tabs (second mistake is too shallow tabs which ended up in the wasteboard because of this) internal piece separated and… well LR and the bit survived but additional unplanned cut appeared in the struct Now I know the bit can survive 10 mm depth cut in one pass…
For some reason the “internal” line has been cut at depth around 3mm . I thought it because of skipped steps of something like that but then it continued using normal path… Looks like yet another ramping magic, not sure what I’ve enabled ramp in the settings for thought but it was not a good idea.
Still half-baked… I hope to replace the table with torsion box which can be folded in the future, boxes for control board and screen will be changed very soon (being printed already) as well as other side (not X range is limited because of it).
Gave up on Chinese bits and bought ones from the local manufacture (~15x more expensive). Now it cuts 800 mm/min 5mm deep without any issues and such speed is comfortable both for me and the machine.
Modified the board case a bit (well, redone it from scratch ). it’s vertical now. Replaced mount with 3d printed one (was made from the plywood before). And installed structs, It’s time to make proper spoilboard…
The machine works just fine and did some “project” already (like urgent manufacturing of the garden bench, gifts etc etc), steppers are cold (around surrounding temperature) during the operation so I’m quite happy.
The only things I’m not happy with are:
My ad-hoc built table, working on building new, folding one.
Wiring of 230V lines needs some love. As it depends on previous issue It will be sorted out together with the new table.
Noise. This makita stuff is noisy! taking into account my CNC is sitting in the big metal box (sea container ) this is just too much of noise. So I’ve purchased Vevor 1.5kw spindle first tests showed that noise level is not even comparable with the Makita router.
Now I have another issue… reading docs how to implement estop on cheap VFD, apparently cutting of the power of such devices is not good idea.
Few hours of playing with spindle ended up with one bent bit, broken top tool mount and “looseness” of the entire machine. For some reason (I think it’s cheap Chinese straight bits to blame) CNC with the spindle vibrates a lot during cutting. Feeds and speeds were much lower than one I use with Makita (500mm/min, 5DoC while Makita with quality downcut bit can handle 1200/10 without any issues).
Switched back to Makita, finished the job and ordered quality bits from the local manufacturer (same as I used with Makita router but with 6mm chuck).
Now I have to figure out what causes play of the LR core. It moves ~2mm during Yaxis direction changes looks like the bearing (“internal” ones, which are harder to reach) are not engaging with the tubing at all.
Solved by retightening bearing axis nuts. Back in operation with noisy but reliable Makita router
) thus the size. 2500mmx1250mm working area.
