Ultimaker Glass Heated Bed & 3-point Levelling

thingiverse

Assemble your 3-point levelling before disassembling your print bed. Use printed relay fixture/clamp with a 12V and >15A power supply on a Prusa MK2 heated bed. Connect the thermal fuse in series to the heating circuit, taping or cementing it under the printing bed near the heating element for safety. Cut a 5mm thick natural cork tile for your print bed, making sure it is untreated and heating-safe. Solder power leads, LED, and resistor to the marked side of the heating element, ensuring protruding solder doesn't remain. Position the heating element on the glass print bed with 3-point washer seats up. Mark the location with a felt marker for easy repositioning when securing in place. Pass power leads through the masked out window of the cork tile and position the cork tile on top of the heating element. Drill 2x3mm holes at calculated distances to secure nail plates, using blind nuts with M3 screws loosely attached. Clean recipient locations with alcohol and glue the blind nuts to the nail plates, using superglue and accelerant for quicker positioning if desired. Position the thermistor at the centre of your bed and tape in place with Kapton tape. Secure cable ties to loop and secure sensor and power leads. Connect T-plugs to power leads and relay, using a 150ohm (1W) resistor in series for a 12V relay if an 18V one isn't available. Attach the relay to your Ultimaker's bottom with a printed fixture. Enjoy improved prints with no warping and easy removal off the glass bed, possibly using Kapton tape for better PLA adherence. If using two thermal fuses in parallel, carve out a pocket in the cork backing for them. Consider adding more blind nuts per nailing plate or reducing curvature to reduce springing force on super glue joints.