Temperature Controller for Heated Bed Plate?

[3dguy 0]

I am about to put together a heated bed plate for my Ultimaker and I am unsure how to control the temperature of the PCB for the bed Plate.

1. Should I connect to the Ultimaker with a relay?

2. Should I connect to an external controller? If so which type?

I have a 8.5" x 8.5" PCB Heatbed MK1, a 9.5" x 9.5" x 1/4" Aluminum Plate, a 9.5" x 9.5" x 3/16" piece of High temp Ceramic Glass, a Thermistor, a12v external Power Supply, and Ceramic Mill Board to insulate between the heated components and a acrylic plate to mount it to the z-stage, and Kapton Tape.

I am open to either way. I am just trying to figure out which way provides the best and safest connection for me and the Ultimaker.

 

[owen 19]

I use a relay. I like it as it has never failed and it's small and has no heatsink to worry about.

 

[gr5 2,265]

The nice thing about running HB through UM is that when the print finishes it automatically shuts off the HB. That's probably the only reason but it's a pretty good reason. If you start a print and then go out to lunch or go to sleep or get a phone call or whatever, it kills HB power when done so when you come back your print is ready to pop off the bed.

 

[3dguy 0]

Thanks for the replies. Could you suggest a specific relay to use to connect the PCB to the Ultimaker? The Wiki states that a protection diode is recommended, do you know what kind of diode?

I just started to get into electronics last year so this stuff is still very new to me.

 

[owen 19]

I'm fairly sure the diodes are already in place on the PCB. I use an auto relay rated at 40 Amps with 12V coil. It has given me no problems.

Link to schematic here. http://reprap.org/wiki/Ultimaker%27s_v1.5.3_PCB

 

[gr5 2,265]

This is true. The flyback diodes are already there so don't worry about diodes.

 

[3dguy 0]

Thanks for the wiki link, it is informative. I have a thermistor, would you recommend using it or a thermocouple? If a thermocouple, what type?

 

[gr5 2,265]

This one is great:

https://ultimachine.com/content/thermistor-100k

And pay the extra dollar for the sleeves. Note that ultimachine is not associated with ultimaker.