The Onyx is a round PCB heated bed for RepRap 3D printers. Designed for SeeMeCNC's Rostock MAX, the bed is also useful for other printers too. The bed has spiral traces and draws around 10A current.
The outside diameter is 310mm. The six mounting holes are 3.85mm diameter for 2~3mm size screws. It is preferred to countersink the six holes and use flat head machine screws for mounting. 4-40 screw size also works good with mounting the bed.
The electrical connections are 12VDC +/-, thermistor, and LED with resistor. It is recommended to solder all connections on the bottom of the Onyx.
1. Be sure nothing is soldered or sticking up about the surface of the heated bed during assembly.
2. Bend the thermistor leads 90 degrees close to the glass bead.
3. From the bottom of the Onyx board, position the thermistor in the center hole of the Onyx. Do not let the leads of the thermistor touch the plated center hole!
4. Solder one lead of the thermistor to a pad. Polarity is not important. Check the position of the thermistors glass bead. Solder the second thermistor lead.
5. Thermistor control wires are soldered on the bottom of the board beside the power solder pads.
6. LED connection is optional. For LED connection, use a 1k to 4.7k axial leaded resistor is soldered to the bottom (depending on your LED current requirements). Do not stick the leads through. A 3mm LED is a good size.
7. For power connection, use at least 18 AWG wire. The board is designed for 12VDC supply voltage. Positive to + and Negative to -. Lay the wire across the solder pad on the bottom of the board when soldering.
Source Files for production:
Use Gerbv to view these files: File:58742 R2 ONYX 27-DEC-2012.zip
Insulator for underneath the PCB: File:Onyx insulator.zip