Progress on the AX-03 Railgun. X/Z axis is pretty much done.

3D Printing
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Progress on the AX-03 Railgun. X/Z axis is pretty much done. I just need to sort the lead screw top restraints and closed loop belt tensioner. The Leadscrews are highly constrained with 608ZZ bearings top and bottom to remove any chance of Z wobble, plus the parts go around the 2040 upright extrusions which will help as well. I’m not overly happy with the Z motor mount at the moment, but I think I’m just going to design a strap to go around the motor to stop any movement.

It’s then just the Extruder Carriage and endstop mounts to go and it’s done. I’ve already ordered the Extrusions, which should be here next week. For those asking where the electronics will go, it’s going to be on the right side of the frame, it’s being designed with that in mind, so all wiring will be on the right hand side of the printer, so X will home to max and the Z endstop will be on the right hand side.

Electronics-wise, it’s going to be a smoothie printer, I’m not sure on the board, yet, but leaning toward @raykholo 's Cohesion Mini. It will mesh level with a fixed bed as I really do not want to be screwing around with 4 point levelling.

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Constraining the lead screws is a good idea if they are very straight (mostly to protect them). Otherwise constraining may give you more Z wobble I think.

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Yes the rails will pretty much stop wobble, however, the bearings are needed to actually hold the left hand lead screw in place, so it makes sense to actually use the bearings.

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Both end bearings CAUSES wobble. Skip them. It’s safe to assume all low-cost screws are bent.

Mount the screw on a flex coupler or the motor on an astrosyn damper, and don’t add any bearings at all (except the ones in the motor itself), and you won’t have any z wobble because the screw can’t push on the printer. The thread taper on the nut keeps the screw adequately centralized.

Edit: left hand screw, one bearing on bottom only, or if you run into issues with belt tension pulling on the screw, two bearings on bottom and the pulley between them.