Raspberry Pi (or other board) Internal Mount for Qidi Plus4

This is an internal board mount for the Qidi Plus4. It fits over a couple of posts near the mainboard.

I designed this to hold a raspberry pi and buck converter so I could use the pi as a host for stock klipper. I followed DrFate09's instructions to do this. My printer was crashing partway through long complex prints with many objects. I tried every tuning guide under the sun to make it more stable with only very limited success. If your plus4 is crashing with "timer too close" errors, and you know your way around klipper and a soldering iron, this is the best solution out there.

Printing Instructions:

Print with a rigid, heat resistant material. I used Siraya PET-CF, partially because it prints well without a heated chamber, and I had the pi hanging out of the back of the plus4 on my workbench when I realized I was going to need a mount for it. Do not use PLA or PETG. ABS or ASA would probably be fine, but I would use something fiber reinforced for the rigidity.

I printed with 4 walls and 25% honeycomb infill.

Mounting Instructions:

The mount secures to the posts to the left and bottom of the mainboard, circled in red here:

It slides over the top of them and secures with self threading m3 screws, or, for a more secure connection, you can drill out the posts with a 4mm drill (carefully! use a depth stop or you'll punch right into the main chamber!) and insert m3 threaded heat inserts into them, then secure with m3 cap screws.

Model Files

• plus4 pi4 mount - heat inserts.stl: mount for the raspberry pi 4b and buck converter using ruthex m2.5 inserts for the pi and m3 inserts for the buck converter

• plus4 pi mount - 2.5mm nuts.stl: mount for the raspberry pi 4b using 2.5 mm nuts press fit into the back of the mounting board (this is the one in the pictures. I didn't have any 2.5mm heat inserts). The buck converter still mounts with m3 inserts

• plus4 mount - blank.stl: a board mount with no holes at all, except for the posts it attaches to. useful if you want to use your slicer to put your own holes in the mount, or if you want to attach something with adhesive.

• plus4 mount - blank.f3d: fusion file of the board mount. no holes. do whatever you need to with it!

Other things you might need to use this mount:

• Ethernet coupler to extend the internal ethernet cable

• 14ga wire and connectors to extend the power leads to the print bed

• 22ga wire and connectors to extend the chamber temperature sensor

• 22-24ga wire and connectors to connect power to the pi and buck converter

• Upgraded cooling for the mainboard/electronics chamber

Links

• DrFate09's instructions for bypassing the onboard MCU and running the plus4 off a raspberry pi

• Buck converter I used to power the pi. I connected it directly to the 24v power supply and dialed it in to ~5v (double check with a multimeter) before connecting the pi. The USB ports on the plus4 mainboard do not supply enough power to run a pi4 without throttling. The mainboard does have a 5v header on it, but I was unable to find documentation on how much amperage could safely be pulled. I erred on the safe side and used a buck converter.

• Ruthex threaded inserts used in this model.

• Siraya PET-CF I used to print the mount shown in the pictures.