RepRap: Blog

The previous Flexure Coupling was a bit too stiff, and also perched the connecting nut right on top of the coupling. This in theory allowed a bit of play for self-centring but but in practice this needed a lot of manual (and physical!) adjustment. As I noted when building a μRepRap for someone else with proper limit switches etc., it also tends to strip when you hit the limit, and have forgotten to connect the switch. Amazing how your attention focuses when you're actually going to hand something over to someone else. So, new version:

 

This one completely engulfs the nut in the tapered cavity, and has much thinner flexures. This gives more lateral play for removing wobble. Note that this flexure design doesn't tend to twist and introduce backlash. Quick test shows they centre pretty well, so I'll install a set on Maus #2 and see how they go.

The buttpain here is that the coupling now needs to be printed with a brim as it is too delicate to stay on the bed otherwise. So I have to redo all the build files in git, rebuild and upload the build plates, take new photos, and update the build and calibration documentation. Damn.

The Maus C needs to be mounted on a baseboard of some kind to provide additional rigidity. I'm using lasercut acrylic for the top because I want to see in, and MDF for the bottom because it's cheaper. I'm using two layers so that I finally have somewhere to tuck the electronics, and remove the Bloody Great Chunk Of Plywood from its resting place on my desk for the last year or so.

I made my boards a little too short, and have added a couple of extra holes to the ones on Github. I'll add the pillar and feet designs when I'm happy with them.One "Gotcha" is that the Z motor needs to come off to install the pillar in that corner, but that's not as hard as it sounds and I'll live with it for now.

I've been adding up the Bill of Materials on Amazon, as ordered from New Zealand (to be honest, a really crappy place to order things from) and it came to about NZ$300, or €160 without the USB microscopes. You could do those for around $120 if you go for bare minimum resolution, and I'm assuming you've got a few wires and minor items around like glue etc.

 I was pleasantly surprised to see that you can still get the RepRap RAMPS kits for around NZ$33!

Quick update. The FAB25 RepRapMicron talk schedule is up:

RepRapMicron - Micrometre scale 3D Printing from scratch

RepRapMicron is going to be presented at MIT's FAB25 in Czechia in July, which involves me doing a presentation, show and tell, and two workshops. Hence lack of blog posts while I sort that out.

Anyone else going? https://fab25.fabevent.org/

With an astounding total of 253 fasteners, the Maus C Alpha "Bill Of Materials" has arrived to accompany the build docs and full release of pre-built STLs.

https://github.com/VikOlliver/RepRapMicron/blob/main/maus/Maus_C_V003_BOM.csv

 

The construction section of the manual is now on the GitHub Wiki here https://github.com/VikOlliver/RepRapMicron/wiki/Maus-C-Build-Process and will be transferred to the RepRap Wiki as things progress. So that means I've had to build another one in order to document it and work the bugs out. I also didn't like the Z Tower so I redesigned that. I still have to upload the as-built OpenSCAD files and STL print sheets. Here's the happy couple:

 

And in case it's not clear from the photo, that new Z Tower (will upload tonight after housework is done) which replaces the god-awful assemblage of brackets and Metriccano beams: