Just building the MPCNC and looking on some advice on the corners/legs.
Not sure if needed, but I was thinking on adding some rigidity to the structure… and came up with this basic design.
[attachment file=“new corners.jpg”]
The idea is to use 6mm all threaded rods to ‘sandwich’ all the parts together and secure them tightly to the table. I’d still probably go for the original spacers between the conduits. Perhaps a top plate might be needed, ideally a metal one.
I’ll be happy to hear your thoughts on this, is it worth the effort and filament, any potential drawbacks.
If you have a fixed leg height and a single piece from top to bottom then you might benefit from a gusset. It would be very efficient in that you gain a lot of stiffness for a small amount of material. A gusset is not so easy for a variable length leg where the top and bottom are separate.
Thanks all for the comments. Most of the other stuff is printed and assembled, so I might go with this design for the legs.
You can’t imagine how helpfull i find the words ‘of that size’
I really like the Totem corners, that’s what leaned me into this new design, actually. But the main difference, and also where the advantages might be, is the lower part (green one). You can gain a lot of rigidity (at the expense of some filament), simply by means of leverage - that’s what I think, at least. We’ll see.
Belts and endstops will go on separate plates - you only see some of the mounting holes here (I’m lazy, I know). I like modularity, you can make minor updates without assembling and squaring everything from scratch. But we’ll see how it goes - iterative design, they say… drives me nuts sometimes
Grow the pieces a little so the spacing of the holes is 50.8 mm(2inch) instead of the 40ish mm they are now .
You now can use peg board to align the machine base (or even as part of the base).
With this spacing, before putting the middle z gantry onto the x/y rails, a sheet of peg board temporarily slipped over the threaded rod on top could be use to square it up before the x/y pipes are snugged up to ensure square.
