Throw away all the belts

[antiklesys 3]

I was wondering if anyone has yet tried to remove even the long belts by replacing the standard 8mm rods with M8 threaded bars and direct drive those.

Wouldn't that help in increase the precision?

 

[IRobertI 520]

I don't know of anyone that has. I would assume the problem is the speed at which the print head moves. With a standard M8 threaded rod you would have to rotate it very very fast to match the speeds that the belts provide today. Changing to something with a higher pitch (or is it lower? I can never get that right) so that less rotation results in more movement would make it easier, but then you're reducing resolution again.

In the end I don't think the resolution is a problem though. Other factors like the shrinkage of the plastic can produce errors that are magnitudes bigger than the errors in the belts.

 

[jhertzberg 19]

I wonder if you could adapt the http://www.thingiverse.com/thing:112718 on Thingiverse to act as your sliding blocks, since you could pick the optimal pitch. There is already a design there that uses 623ZZ bearings at a 38.5 degree bearing angle. The challenge will be block clearance and drag from the unpowered side. I suppose you could either leave belts for power transfer, or add two more motors, but that might defeat the purpose.