Workbench CNC Mill

Well, for a given value of finished. There's still so much more I want to do, like a 4th axis, move my old Prusa 2's hot end and extruder onto a quick mount head, add laser etching....

Anyway, the project was finally finished over the weekend will the completion of the electronics enclosure I milled out on the machine itself. As a brief rundown of performance, at this point I'm comfortably cutting MDF and ply at 1000mm/min, 4mm DoC, with an accuracy of +/- 0.02mm, if you're willing to believe my digital calipers (It's just occurred to me I should probably have photographed that, watch this space). I haven't yet tried milling aluminium, but with the 5kg spindle weighing down the gantry and smoothing out the vibration from the slightly bent lead screw, I really can't see any major problems. The machine barely even works cutting soft wood.

From the last update, you can see my super cheap E-Bay spindle package, which came with the 2.2kw spindle, full set of ER20 collets, HuanYang VSD (which to this point is also working well, but feels kinda temporary), and the submersible pump below the enclosure.

The software toolchain is still Autodesk Fusion 360 into Mach 4, both of which are working without even the slightest hassle.

I intend to post a full set of DXFs for the aluminium components, a parts list, and if I get really keen, a set of build instructions.

Probably the single most important learning I can pass on from this project is to build the dust boot before you cut your first MDF piece. Trust me on this.

Here's the machine actually working! I put together a very simple demo page in Inkscape to make sure there would be no nasty surprises (there were), and I'm ecstatic about the outcome.

The first issue was the backlash on the X-axis. As previously mentioned, that ball screw arrived slightly bent, and it shows (look between 3-4 o'clock on the circles). Not only is it on the order of 10x worse than the other axes, it's not consistent across the length - huge on either end and negligible in the middle. The screw has to go.

Second issue is the obvious lack of bed leveling - not a huge deal as the tools I'm waiting on include a bottom cleaning bit (seriously, who named that?), which will plow through my sacrificial MDF like butter. I'm also in the process of rebuilding the whole thing, this time actually paying attention to abstract concepts like "square" and "true".

I'm guessing the whole slippery-pen-in-zip-ties tooling played absolutely no part in the inaccuracies, as I can assure you zip-ties are still an integral part of keeping heavy industry running :)

Back to work for another 8 days, but I'll have a spindle and tool set waiting for me when I get back.

Well As you can see, a clear contender for worst enclosure of all time. It'll hold together until I get the spindle and VSD and can lay everything out properly though! You can also see the mill now with tool plate, all drive tabs, and motors fitted. It's currently joggable through Mach4 and an Ethernet Smoothstepper.

The power supplies are MeanWells, and I'm using a Gecko G540 4 axis board to drive my steppers. I was absolutely not keen to toner transfer this equipment like I did on my RepRap. Luckily, once I get an engraver and a little 3W laser diode fitted to this thing, I'll never have to print my PCB layouts again.

Oh and yes, the steppers will have 4 pin connectors fitted, I was just in a hurry to see if it all worked :).

Well, all the electronics arrived, with a few bonuses thrown in (highly recommend Homann Designs if you're an Aussie). I didn't get a chance to throw it together unfortunately.

The major drama this break was that I managed to build the X-Axis drive plate and connect it. The ball screw got slightly bent in transit (the center moves by 1mm up and down when rotated), but I thought I'd get away with it. Unfortunately when I drove it with a hand drill, it ran, but the whole machine shakes if I run it too fast. I'll have to replace it I think.

First entry, then. As you can see from the photos, I've got all 3 Axes built and assembled, and miracle of miracles, everything seems to fit. I'm pretty sure my compound saw is off by a decent fraction of a degree, but the drill press is actually pretty damn good for being the cheapest available.

I ran a drive test on the Y-Axis today using a hand drill, and it turns easily from end to end in both directions. I haven't yet made the drive tabs for the X and Z axis, but given they're much shorter, I'm hoping they'll be more forgiving anyway.

I also gave myself a minor heart-attack ordering all the electronics in one batch. This includes the steppers, but not the spindle or VSD. Those I'll get as a pack off E-Bay once I've got the drive gear up and running with Mach 4 and a pen.

Oh yeah, and I should probably add a bed at some point...