Now that I have the X axis mounted and working on the printer and the Y axis project is nearly completed, it’s time to start looking at the Z axis. I want to use as many off the shelf parts as possible, so I am going to attempt to design it to use the Openbuilds Mini V wheels and the existing Mini V Wheel plate. I’m also going to try using a single 20mm x 20mm Vslot extrusion per side. I am concerned about the potential flex in a 20mm x20mm extrusion, so I plan to also include 2 or 3 backbone stiffener segments running perpendicular to the extrusion and tying into the existing vertical frame rails. The top plate and bottom motor mounts on both sides will receive fairly major surgery to make everything fit and will need to be replaced on both sides. I looked at going with a 20mmx40mm extrusion but I can’t fit it in with the mini v wheel plate and the existing control box, and if I turn it sideways, I’ll have to get a custom plate made. Plastic would have too much flex for that particular application. That’s a definite possibility, but I’m trying to keep this as accessible and as low cost as I can, and custom milling is definitely not low cost.
I’m also probably going to replace the Z endstop target with a micrometer barrel. I plan on going with automatic bed leveling soon, but at the same time I still want a fallback endstop just in case, and there may be others who want to stick with regular leveling for now, but want more precision. I may make 2 variants for people who want to stick with the existing piece since micrometer barrels can be somewhat expensive.
I’ve ordered the following hardware for the prototype:
4 x Aluminum Spacers (Size: 6mm)
4 x Eccentric Spacer (Length: 6mm - Mini Size Wheels)
2 x Black V-Slot™ Linear Rail (Size: 20mm x 20mm, Length: 500mm)
4 x Mini V Wheel Plate™
8 x Xtreme Mini V Wheel™ Kit
8x 25mm low profile M5 nuts
Hardware cost with shipping $129
This is still a very early stage project. If anyone has any ideas or requests, please let me know. This will also work with my Anti Z wobble nut (V 1.0 or the still as yet top secret V 2.0) or the stock nut mounting pieces. A future variant of this project may also incorporate Belt drive Z rather than Leadscrews
More to come