I would recommend rotating the bed 90 degrees, while it applies more leverage to the cantilever style bed, it shortens the x axis rods, which means less moving mass.
I’m not sure how much better 9mm belt would help, it might be easier to just switch to a bigger profile belt like the gt2-3mm.
How are you tensioning the belts?
Hi @Stephanie_A Thanks for your input. I had entertained that alternate orientation, but it would leave the best “viewing” face of the printer being the narrow wall (if you follow), and I really want good visibility to the printer in action for training and demo purposes. The saving is about 54g in mass (approx 70mm x2 of 8mm stainless rod). Changing to Bowden saves about 500g (single extruder) just as a comparison of possible weight savings. Meeting design constraints is a constant challenge and compromise, but fun and always leads to good discussion.
On belt-tension - I designed in a small amount of motor movement on their mountings (I’ll post a pict), but that’s proving flawed and awkward, so I’m entertaining adjusters build in to the x-carriage. Currently I just pull them tight and push them into notched slots under the x-carriage.
I’ve had good luck with slotted motor mounts for belt tensioning, personally.
The thing with swapping X and Y isn’t really about mass so much as bending deflections. Bending increases with the cube of length, so relatively small changes in length can make a big difference to ringing. If you make the longer rods stationary, you can make then larger and stiffer without any mass penalty, and the lightweight moving rods can be shorter and stiffer.
But, for a demo printer, there’s value in visibility!
@Ryan_Carlyle Good points and something for me to keep in mind. Belt tensioning via motor adjustment has probably less re-design work than x-carriage based adjustment with my current setup.
Larger diameter stationary rods might also provide additional structural rigidity to the frame.