Snapmaker J1 Loft & Upgrades

Loft:

Loft floor is raised 100mm above top of printer to prevent sharp bends in filament path. Loft is fully enclosed to keep humidity down, and also to keep heat in the print chamber below. There is a temp/humidity sensor in the loft and one in the print chamber. The loft fits 8 rolls of filament, with 2 of them feeding the extruders below. I designed these panel mounts to mount the panels to the extrusion. I used inside corner brackets to connect extrusions together. 
Note: the bill of materials includes equally sized panels for front and back. That means you would have to unscrew a panel or roof every time you want to access the filament. If you want to have a hinged door on the front for easier access, you’ll have to change the size of one panel to accommodate hinges. I just cut mine in half on a table saw to make double doors. Aluminum Angle pieces are to support the weight of the filament spools. I drilled and tapped the extrusions to secure those pieces.
Aluminum and PET panels are from Misumi. search part numbers from bill of materials. 

Raspberry Pi & Electronics:

I designed this electronics case to mount the raspberry pi (with 10-amp relay hat), 2x standalone 30-amp relays, a buck converter, and an IEC320 C14 mains voltage receptacle. The case mounts to the back of the printer and wires are fed through one of the holes for the stock filament spool holders. I used the foam from the hot-end packaging to fill gaps around the wires to prevent heat from print chamber getting into electronics case.
-The buck converter input is 24v from printer PSU and output is set to 5v to power the Pi. 
-A 30-amp relay switches power from the PSU to the printer main board and is controlled by Octoprint PSU Control plugin. 
-The other 30-amp relay switches mains voltage power from the IEC320 receptacle to the chamber heater. 
-One of the 10-amp relays switches power from the PSU to the exhaust fans. 
-Other connections to the Pi include E-stop button and 2x temp/humidity sensors connected to GPIO, and ribbon cable for Pi TFT screen (running Octoscreen).

Chamber Temp Control:

I made this chamber heater but with 110 volt version of heater and 110 volt fan. I used 2x 80mm fans (24v) for exhaust to keep chamber cool for low temp filaments and to prevent chamber from getting above 60C for high temp filaments. Above 60C will probably overheat the steppers. Temp control is handled by Octoprint Enclosure plugin utilizing the temp/humidity sensor I installed in the chamber, and relays to switch the heater and exhaust.

Physical E-stop Button:

Installed a momentary-press button that is wired to gpio on the Raspberry Pi and controlled by the Octoprint Enclosure plugin. It can be configured to send whatever gcode you want when the button is pressed. The usual is M112 full shutdown, but this also disconnects the printer from Octoprint and that annoys me. I use M410 quick-stop to kill motors and M140/M104 to turn off heat bed and hot end heaters.