I needed replacements for my mounts that were slowly deforming in my heated enclosure(40C) due to them being made from pla. Also, as is standard for Tronxy, the mounts came with warping by the threaded bushings that required me to shim. I couldn't find much out there for my P802E at the time, so I made my own. I made the motor mount extra beefy while staying within the original dims. I also added cable tie features around the bearings as my old ones had loosened up. I did not spare any plastic when I printed my mounts. I did 4 walls and 70% infill with abs. Yes, that infill was way overkill. Supports are built in. Obviously, you will need to orient them so the anchoring discs are on the bed. I did tweak the motor clearance hole after printing mine to a teardrop shape as it was a little messy there.
On the right side I made a belt tensioner that hugs the ouside of the mount and is adjusted via 4 screws. Yeah, a lot of tensioners use just one or two screws, but four is nice and stable and you rarely have to tighten. This will work with the original mounts as well. You reuse all the original hardware plus four m3 screws and nuts. Prints without support though you may need to do a little cleanup in the countersinks. I should have angled those. Maybe I will fix that eventually. 20% infill is plenty for this part. Print with the right end side down. -Not the orientation that it comes in as.
Also added a file for a x-tensioner with a geared idler pulley. Uses a GT2 20 teeth pulley with a 5mm bore. This is supposed to help reduce belt vibration. I saw little difference.