Delta fun

A while back I bought a semi assembled Anycubic Kossel Linear Plus 3d printer from a Tesla engineer down in the bay area. He was selling it pretty cheap because it had just become a project he couldn’t finish while working 80 hour weeks (WTF, Tesla?!). I completed the build but could just never really get reliable prints from the thing – I’d often have issues with what looked like one of the stepper drivers losing a lot of steps and the effector drifting off to the side.

The stock configuration came with the “Trigorilla” motherboard which is a perfectly fine atmega based board, but doesn’t have support directly for TMC2209 stepper drivers from Trinamic. One of the things that bugged me about the hardware on this printer was that the screws for the endstop switches just barely rubbed on the belts, and, uh, no thanks. The endstops also basically took up about half an inch of possible travel – that could be more build area.

Switches DELETED!

I ran into what was either a bug with Marlin or an issue with the SKR V1.4 Turbo board wherein the three tower motors (some people still call them X, Y, Z, but I’ve also seen Alpha, Beta, Gamma, which makes more sense) would run just fine but the extruder motor wouldn’t turn. The most I could get would be the motor being enabled which caused it to get a hold current, but then it just wouldn’t move. I kinda have in to cargo cult ways and just changed that driver to an A4988 from the old setup. A4988’s still a perfectly fine driver with microstepping, it just isn’t as quiet and doesn’t have the missed step detection, which didn’t matter to me for the extruder which doesn’t have to be an absolute position sort of system.

Now what to do with all this horror pasta?! As soon as I get it up and printing I’m gonna make a little box for the controller.

The bracket it’s on is reused from the stock setup which had the controller right under the heated bed! I didn’t like that. I think that was inherited from the early Anycubic Kossel delta printers which originally came out without the heated bed – that came out as a later option. Mine has the glass bed which I put the build plate sticker on (…why?) – I’ll probably strip that off later as I’m a believer in the magic of the glue stick. All hail the glue stick.

I can’t figure out if it’s actually possible to do Marlin’s delta calibration without a leveling probe. I tried using the delta calibration menus and just didn’t get anywhere. A probe is on order and I’m going to get some spiral wrap or split loom and Velcro for all that… aaaargh!