Big Boy SSR Mount For Creality K1 Max

Designed specifically for Creality K1 Max printers running high-wattage graphite beds or other heavy loads, this mount supports an oversized heatsink for extreme cooling capacity. Without proper SSR cooling, you risk thermal runaway. When an SSR overheats, its internal resistance drops, which causes it to pass more current and heat up even faster in a feedback loop. This can lead to the relay locking “on,” keeping the heater powered even after the printer tries to shut it off. In a 1000 W+ AC bed setup, that’s a serious hazard. The bed can keep heating uncontrollably until something fails or catches fire. A large heatsink and stable mount prevent that by keeping the SSR within its safe thermal range, ensuring the relay can actually switch off when it’s supposed to. This mount features a honeycomb design to improve cooling further and reduce weight, with additional mounting points for rigidity and isolating unused wires without cutting the heatsink. 

ALL PARTS ARE DESIGNED TO BE PRINTED WITHOUT SUPPORTS
Drill the Cover holes all the way through using an M4 drill bit for M3 heat set inserts (not a typo). This will allow you to secure the cover by putting the screws through from the inside of the printer, avoiding long screws touching anything inside the printer.

Can be used to mount any SSR without a heatsink or you can cut and drill the under tray to fit the heatsink and cover, and lightly trim some of the unnecessary plastic between the two tall screw mounts (on the right, with the printer oriented with the psu on top and mainboard on the bottom right) to make the mount sit fl
ush. Not a huge deal but I like to do things nicely. 

Install the SSR mount before the PSU bracket.

The PSU bracket adds additional support for the SSR mount and a bit of safety in case something comes loose and would have otherwise shorted to the PSU. Shut down the power, make sure it is completely discharged before working and stay grounded. Don't touch components with your hands or anything conductive. It's dangerous. Use your brain. Remove the screw from the right side of the PSU (with the machine oriented with the power supply on top, mainboard below. Slide the cover off and remove the two screws on the bottom. Now you can install the bracket using the same two bottomscrews. You will need to hold the components in place to get it screwed in properly, otherwise they move around. Slide the cover back on and install the last screw (this one does not secure any components)

COVER INSTALLATION

Secure the template to the lower corners of the PSU fan grille. Match the orientation shown in the reference image, with the mainboard fan grille positioned at the bottom-right. Outline the square inside the template, then drill the mounting holes first. Cut out the square only after drilling to avoid cutting too far and losing alignment with the screw holes.

Drill completely through the printed cover with a 4 mm bit, then heat-press M3 inserts from the flat side. The insert length or diameter doesn’t matter, as long as they’re M3 size.

Insert the screws from the inner side of the electrical bay cover so that they point outward, rather than extending into something that could cause a short.

M4 heat set inserts for the SSR mount and PSU bracket (doesn't matter what type)
M3 heat set inserts for the SSR cover (doesn't matter what type, I used m3x5x4 voron)
Taller feet required for large SSR and cover
M3 and M4 Screws
Heatsink and SSR links