8mm lead screw block

thingiverse

This object was made in Tinkercad. Edit it online https://www.tinkercad.com/things/6KA7ydmEJBD It has a center height specifically matched for a 10mm bearing block, which some 8mm bearing blocks from china will also have. This is about 4mm higher than the normal 8mm bearing blocks I've seen on Thingiverse. Screw holes can fit a 4mm screw, but for a t-slot install you will want two 3mmx20mm (M3*20) I printed on its side with a solid infill, but printing at 102% or whatever can perhaps make a stronger part. Just shave off the zits after. I tried doing annealing, but I found it was harder to get exact dimensions. It would lead to stronger parts. If curious: 102.35% print size, annealed at 90-C for 30-minutes using PLA-CF worked though, if I bothered to clean the part first of zits. I printed the part slender, so it would fit in the small space left between four bearing blocks. It's more than strong enough. I added a spring and a lose t-wing like nut on one end, to act as a back lash nut. The wings on the nut would prevent it from spinning more than about 130-degrees, so works. I didn't need to build the backlash holder into this part as a result, making everything a lot easier to assemble. This was used to upgrade a cheap 3018 Pro CNC with a t-slot vertical plane. Overall, it's slightly more rigid than it was before, with more vertical height. I'd need to replace the bearing blocks and 8mm rods with either braced 12mm rods or 12mm linear rails, but it's not really worth it. I also replaced the 8mm threaded rods with finer pitch ones, so I get more torque but slower speeds. Given how I don't want to get a new CNC controller to power larger steppers, this seemed to be a sensible option.