Adding a heated bed to your Printrbot affords you the opportunity to experiment with a wider variety of materials. However, it does introduce another level of complexity to your workflow. Not only do you have to consider adjustments to your print settings, but now there are new mechanical, and more importantly, electrical components to consider.
Most users that run into problems with their heated bed upgrades see abnormal behavior that could easily be mistaken as a bad Printrboard. Before replacing your board, let’s make sure that you have the necessary power and let’s also make sure that the power is properly insulated so that it doesn’t short out your electronics.
Use Kapton Tape to Avoid Metal-on-Metal Contact
Metal-on-metal contact is the most common reason for problems with your heat plate. These contact points cause your electronics to short, which can manifest itself in a variety of ways; connection errors, erratic movements, power “brown-outs”. To avoid shorts, use Kapton tape to better insulate your components.
Thermistor - Wrap a small piece of Kapton tape around the thermistor bubble and wire traces before attaching it to the bottom of your metal print bed. This will prevent shorts from the wire traces.
Heat Plate Traces - For production units at PBHQ, we isolate the thermistor wire, heat plate leads by adding tape to the bottom of the print bed. To be completely sure that you are avoiding metal-on-metal contact, consider lining the entire back of your heat plate with Kapton tape. This is an inexpensive way to protect your electronics. Use the tape as a “backing” for your heat plate and then use something like a paper clip or ball point pin to punch holes for your screws before installing the plate in the print bed.
Other Causes for Shorts
When inserting the heat plate wires into the screw terminals on your Printrboard, make sure that the wires are completely enclosed in the terminal. If the wires fray and make contact with your Printrboard, this can cause problems.
Make sure that the HOTBED and HOTEND fets on your Printrboard are not making contact. If these fets are touching, your hot end will begin to heat up as soon as you power ON your Printrbot.
Simple 1403 Users: Make sure that you have washers on the right side of your X axis bearing clamp. While it may seem like a minor detail, these washers serve as a crucial spacer. Without them, the M3 screws holding your bearing clamp will make contact with your Printrboard on the underside of the base of the bot.
ATX Power Supply
An ATX power supply is required to run a heat plate on your Printrbot. If you attempt to start a heated-bed print with your laptop power supply, you will get a “brown out” message in your control software and the print will halt.
As a default, the ATX power supplies that we ship from PBHQ are set to 115V for US users. If you are outside of the US, you may need to switch your voltage to 230V. If you fail to set your power supply to the correct voltage, you will damage the ATX.
Finally, be sure to use the proper connector on your ATX. There may be more than one 6-pin connector, but you are looking for the one with the pattern that matches your power extension.