Build plate dimensions

I'm working on modifying the layout file for the reprap pcb heatbed to fit the tantillus. I need the dimensions and hole locations for the build plate to finish it up. I could try and extract it from the dxf file but I thought I'd check first if anyone had them handy...

I added the dimension to the dxf ( the overall dimension of the plate is 130mm x 130mm ).
I have also sketched a board ( with eagle, not tested, so use/modify at your own risk ), two resistances in parallel, each resistance is 1.1mm x 5m ( should be 2.5ohm on a 35um copper board ).
I think the resistance is too small for such a small board. A good idea could be to use a step down converter to supply the board ( and limit the power supplied ) as robonz already did

P.S. As the board is not symmetrical ( fixing holes and 'side cut' ), I'm not shure I've placed the pads for the supply wires on the most appropriate side

Edited 1 time(s). Last edit at 12/24/2013 06:36AM by davidefa.

Thanks!.

If the resistance is too low with two traces running parallel then why not concatenate them and have one long trace? That would quadruple the resistance no? I noticed that the original reprap PCB heatbed was composed of four traces running in parallel for 200x200mm. I rearrange it into a single 100x100 pad with a single trace of the same width. That should produce the same amount of heat as the original with 1/4 the current (assuming comparable trace dimensions). That's one advantage of a smaller print volume.

Now I need to find a place to have the board made. I was thinking this place: [www.seeedstudio.com] . The price for 130x130 board is $60 but at least you get five. Kind of a risk since it's a plated board which the reprap wiki warns to stay away from but I don't want to etch my own and I haven't found any alternatives.

Edited 3 time(s). Last edit at 12/24/2013 12:14PM by wingnut.

There are lots of companies in China that make silicone heat pads with thermistors built in for really cheap compared to trying to make your own. Here is a 135mm square one on aliexpress [www.aliexpress.com] and a 160mm round one [www.aliexpress.com] . Those two are from one company but there are many others that may be cheaper. They will also make you a custom one for about the same price. Further more you can get them in any voltage including mains so you do not have to use an extra power supply, but would need an SSR to control it.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Well shoot! That looks like the way to go. Thanks again Mr Sublime.

Just be sure to specify everything you want. If you do not mention things like the thermistor and its value or voltage and wattage you may not get what you want. Also they will even make them with holes in them for the mounting bolts etc as long as you provide a drawing.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver