Mostly Printed CNC Center Unit

thingiverse

I have spent years designing multiple 3D printers and discovered that bearings often produce significantly more friction than bushings. Here's the solution - replacing CNC center assembly bearings with 3D printed bushings instead. I created one of these prints to see how well it would slide on the conduit, and it slides much better than expected. I'd love to hear your thoughts on this idea, which is still a work in progress. You can find the SolidWorks file for anyone who wants to modify my design. Update: 1/20/2016 During extensive testing, I noticed that friction was caused by the weight of the tool head pulling on the z-axis, causing the entire assembly to tilt. To fix this issue, I added some bottom support, hoping it would correct the problem. Once tested, I'll update this project's status. Update: 1/20/2016 Adding more support for the z-axis didn't solve the issue; the weight of the tool head still causes the entire part to tilt forward, putting excessive pressure on the bottom axis. Unfortunately, this means it won't work unless someone can suggest a solution to this problem. Update: 3/7/2016 - I've ordered 15/16" bushing bushings. Once they arrive, I'll modify this design to fit the new bushings and give it another try. 3/16/2016 - I now have the bushings in hand (available on eBay) and they fit perfectly. I thought I'd need to bore them out, but that's not necessary. I've posted an untested update with support for the bushings, along with the SolidWorks part so others can make changes if needed. At $16 for the bushings and a small amount of PLA compared to the bearings and screws/nuts required for the original center assembly, this could be a real winner. Once my print finishes, I'll post the test results. Based on how smoothly these bushings run on the bars, I'm confident it will work. 3/16/2016 - My print finished, but I made a mistake in the nut placement. I've corrected it in the model and if my test print works, I'll re-post the finished model for testing shortly. 3/18/2016 - The print went fine, and the bushings fit perfectly with everything lining up correctly. I'll post pictures of the completed assembly as well as a video once I've fully tested it out. Print Settings: Printer: Razorbot Rafts: No Supports: Yes Resolution: .2mm Infill: 30% or higher