Aluminium Clad PCB Heated Bed

[Apollyon25]

I just thought I'd share my heated bed design.

We use 1.6mm Aluminium clad PCB material for work reasonably often so when it came time to run another design, I added a heat bed to the design panel.
(I actually added one for my Rostock Mini and one for the Tantillus that others at work have built).

It is simply a pair of 1.4ohm traces spanning the internal area with some bus bar connection traces for the power feed lines.
This gives me 0.7ohms. Or at 12V,~200W.
I also included provision for an LED to indicate when the bed was receiving power. I'd like to also make this a thermal capacity indicator so when the bed is turned off, the LED still glows until it reaches non-skin-melting temperatures, but that is a job for another day. As well as this there is a small hole to mount the thermistor/thermocouple in.

Rostock Mini:

Note: the white circles are where my magnets get mounted for my three-micrometer bed-leveling.

Tantillus:

My bench supplies don't have quite enough grunt to run this optimally, however I can get it to ~55degC (though there is some loss across the air sandwiched between the heated bed plate and the 3mm glass build surface) with my 5A limited supply.

I have these in Altium 14 native format (.pcbdoc), though can export to Gerbers, DXF, Hyperlynx, PCad, Specctra, IDF, Step, Sisoft, Ansoft formats if these suit anybody. Also if anyone is going to use standard FR4, then you need to balance the copper on the other side of the board (Ali-clad is single sided) and it would behoove you to go for the thickest you can to avoid warping at temperature.

If I can help anyone, please let me know.

Jared

[Eaglezsoar]

Good job in making those!

[mhackney]

Very nice! What would you estimate the manufacturing cost of the Rostock Mini bed? Just curious how much that material and fabrication runs.

cheers,
Michael

[Apollyon25]

I think the job was something like NZD600 Total, so maybe NZD200-300 but I had work stuff to make also, so it cost me nothing.

You could also get a 4L FR4 board from a prototype fab house in China and do much the same, just balance copper on each of the layers and it should be pretty rigid and shouldn't bow too much when heated. Just run the copper on one layer orthogonal to the next and it should be quite good. Uniform heat too.

I should really put a thin film of heatsink thermal paste between the aluminium and glass surfaces to improve boundary and air losses...

[vimtut0r]

Hi there,

the heated beds look really nice.

I'm very interested in the one for the Tantillus. Could you share the files? Just a pdf with the layout would be very nice .

Thank you very much in advance


- vimtut0r