Hi, Thanks for the amazing instruction! My build of AR3 is almost finished. However, there is a backlash problem on J2. Here is the video: https://photos.app.goo.gl/NFMZ6KbqRHfPEMBD8 The J2 spindle are 3D printed by PETG with 90% infill. The backlash makes the robot shaking quite a bit when I jog J2. Is this amount of backlash normal? Or do you have any suggested method to fix this? Thanks a lot!

Dear guys, for the 3D printed AR3, how do you tap holes? For those structural components, is there a summary page that specify which hole need to be threaded with which tap size? Sometimes I already assembled a part and then realized a hole is not tapped on it. It will be nice to have a summary of all the tap specs. Thanks!

Plan to buy 6 encoders for building AR3. However, it seems AMT102-V is out of stock on Digi-Key, Mouser and Arrow. A few available on Amazon, but almost double the price and requires a long shipping time. Do you know any other source to get these encoders? Or is there other good alternative? Thanks a lot!