PCB Heated bed design

I see this heated bed PCB all over: PCB Heated Bed
Printed on the board is "GPLV2", so it appears to be an open source design, but I can't find the design files anywhere. Does anyone know where I get EagleCad files, or Gerber files, or anything for this?

Thingiverse.

[www.thingiverse.com]

I bought one but I am not very happy with that design.

IMHO it is underdocumented and underdesigned (example: two tiny soldering pads inconveniently placed, and not a thought about strain relief on the design.

Resistance is way off what it supposed to be (left a msg on thingiverse but no answer). So if making your own, better start from scratch. Calculation hints are in the wiki.

Mine is bang on 1.2R when cold, which gives 10A @ 12V. It came from reprapsource.com. I can't imagine how you could get one with 10 times the resistance. The tracks would have to be like hairs if it was made from copper.

Having said that it doesn't really get hot enough for ABS when driven from 12V, I ended up using 17V. The problem is copper's resistance increases with temperature so the power drops off dramatically. I think it needs a constant current boost converter to work well.

I agree about the lack of strain relief. I managed to rip off the pads and had to scrape the tracks to get a new connection.

Edited 2 time(s). Last edit at 09/01/2011 06:54PM by nophead.

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[www.hydraraptor.blogspot.com]

Yep. 8 times the resistance. Beats me.
Haven't yet started messing with it. will have to wait.

Seems it has several elements in parallell with thin links to the peripheral conductor, a couple of those might be un-connected.

Was it from reprapsource, or XYZprinters?

The other I made works very well. Although I was eager to try it at once, and had not yet received the aluminium plate I had ordered so... ahem... stuff happens.



Edited 1 time(s). Last edit at 09/01/2011 10:31PM by Lanthan.

I Also had two from Reprapsource, they both work perfectly and on both I made the connection pads (scrape away solder resist) about 8mm long before soldering.

I use it upside down with the tracking as the print surface and PET tape + Kapton on the top. they top out at 105 degrees C at +12v but my ABS sticks perfectly with no warp at 85+ degrees and the parts are impossible to remove when still hot but come off with with some force when cold.

I would recommend insulating and isolating it, I did it with Silicon sheet, and PTFE cooking mesh -

Put the thermistor on the top at the edge or corner, if you put it on the underside or in the middle your readings will change when you print a part on top of where the thermistor is placed.









You will find a bit more info on my blog.

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[richrap.blogspot.com]