Well, its been awhile since I posted anything, I lurk pretty much everyday but usually don’t have anything worth saying, hopefully this is more interesting!
I’ve gone a few years without a functional cnc router and finally ran into a project that could really use one, so instead of doing the sane thing and rebuilding my MPCNC or building a Lowrider, I made a weird mashup of both that uses stuff I mostly have sitting around.
Behold the CNCrab…CrabNC? Idk but it kinda looks like a crab to me.
I have some 60mm tubes sitting around from an ikea couch that need to live on in something else, those are the main rails. The rest is as many parts as possible borrowed from the MPCNC or Lowriders. I currently only have the Core rough draft but would like to finish the Y axis ends and have it printing by the weekend.
What do you think? Is this a fools errand? And yes, I know some of the fasteners are facing the wrong way in my assembly…
I copied the two round holes in the tube clamps you have on the Primo, I assume they’re to allow some flex there for adjustment, is that correct?
I considered making them two pieces and omitting the connection over the bearing entirely to save some space, is that something you tried with the MPCNC at some point?
@nate , interesting. Why are you using 2 steppers/belts in the axial direction? Seems like the close distance between the two belts would have minimal auto-squaring effect.
This is as far as I’ve gotten with the end plates, pretty much lowrider 3 derivatives but with the rollers mirrored instead of different prints for front and back.
I don’t know, might be easier just to make the LR2 fit the big Tubes. Not seeing an advantage to moving the Z to the moving part. It might be really hard to get the right tension on the primo core Z tubes like that.
I understand the concern and the pitfalls, but I’ve already built a lowrider 2 and just wanted to try something different with what I have laying around.
I have added a lot of bracing and cross support to the core around the z axis clamps in the hopes it mitigates the issue. I’ve also done some internal geometries as well. I’ll throw up a cross section when I get a chance.
Too bad I gave away my stainless steel lowrider years ago
Here’s a cross section showing the areas I hollowed out to promote more perimeters when slicing, I probably could have taken a lot less and enforced higher perimeter count for these layers, its just an idea I’m playing with that’s worked for other stuff before.
Most likely to start with. I guess I could run both off one driver, I know at one point that was being done with the MPCNC but that’s obviously for a ganged axis instead of more torque.
I really just stuck it there because I had the space, symmetry and flexibility later on.
