I am putting my x5s together and after installing the mega gantry brackets, I noticed my hotend carriage seemed like an extremely week point. It would wobble around with very little pressure.
I believe most of this comes from how the spacers isolate the wheels far from the carriage, producing very little clamping force between the top and bottom wheels. By eliminating the need for the spacers, we can reduce the moment generated by the forces applied to the carriage through inconsistencies in belts/alignment etc, by reducing the distance.
I have printed and fitted v1, which seems to be significantly better than the stock carriage. There are just holes for the fasteners (no captive nuts or anything), but I think this would work if you want to try this one out before I iterate on the second version a couple times.
Update: I printed and install v2, which seems to be significantly more stiff than v1. Trying to flex it at all by hand is really difficult. This is definitely usable, and will free me up to go ahead and finish building the printer up. I'll probably follow up with a v3, but might be a few days.
Video of installed v2: https://www.youtube.com/watch?v=gCRDgNma6bA
Improvements over v1
- This fixes one mistake on the wiring mount.
- Added another part to the wiring mount to better capture it so it can't fall down as much
- It increases the material around the wheels, while also decreasing the gap between the 2020 and the channel it rides in within this carriage by 1mm. (not sure how much this will help over v1, might be marginal)
- It adds a rail for the 2020 to ride on, with the only purpose to add more material where the carriage is the thinnest
Discovered Issues with v2:
- Captive nut holes were too small for me, and too difficult to install. I could, but required some effort.
- The slots for the belts were a hair too tight in v2. I could get them through, but took a little effort.
- All of the small fastener holes were too small, need to make sure these will work with m3 screws. I had to drill them out by hand.
- I'm also considering combining the original carriage with a printed spacer to get the best of both worlds
- Another option would be to add another wheel on the bottom to limit the twisting
Adaptive Slicing (Slic3r) ~65% Quality
I used ABS, since it is easy for me to print with by davinci printer and would avoid any heat issues PLA might have. I'm sure PETG would be a reasonable choice as well.
- Uses the stock wheels and hardware, minus the spacers
- Carriage to Extruder Mount: 2x m3 nuts and 2x 10 or 12mm m3 screws
- Wiring Mount: 2x m3 nuts and 2x 10mm m3 screws