I recently built the Ninja CNC kit from CNCSNAP.com. They include some pretty good harware but I wanted my machine to be able to cut heavier material. So i began making upgrades to the machine. I replaced the laser cut motor mounts with HEAVY DUTY 3D printed ones that are probably a little "over" built. But stronger is better right? I also designed a very robust tool holder that fits the motor they supply with the kit. I love this tool holder, it works great. Note: you will need to drill a hole in the end of the clamp to bolt it together. I recommend a small diameter machine screw. Next I stiffened up the guide rods with a set of support claps on each rod. I made them slightly under sized so you will need to run a 1/4" drill through them. My "Y" axis coupler broke so I replaced it with thing 7059. I can't find the corner bracket file I used to stiffen up the frame but I'll post it when I do. I also bolted together my "Z" carriage because it wanted to split with putting the tool holder one it.
If you have any questions or want me to make other upgrade/ design changes just let me know.
Thanks and I hope you put these files to good use.
Print them out and swap the existing hardware for the new ones. Or add structural components as per the photos.