First pcb, code uploaded

A project log for PCB mill for under $10

pcb mill built from garbage using basic hand tools and little money

shlonkinshlonkin 03/17/2014 at 04:501 Comment

The first real pcb made with the mill is for a tiny robot. It includes such milling challenges as 0603 smd resistors and SOT-23 transistors, as well as a narrow trace running between two 2.45mm pitch holes with pads.

As intended, this shows the limits of precision with this tool. It is certainly far from perfect, and there are some almost fatal bits of sloppyness, but the board is perfectly functional. All of the scratches and cuts came from trying to cut the board out from a larger piece and from running a small screwdriver along the cuts to clear debris. I quickly tested for continuity between all neighboring parts, but everything is properly isolated.

First, here is the intended pattern which was made in Inkscape after laying things out in Eagle.

And here is the result

Also, I have uploaded the Arduino code here. It is very similar to the code for the plotter, but altered to work with the new z-axis and such.

From here I would like to find a way to improve precision, but I doubt it will get a lot better. That's OK. This is functional and thus much better than nothing. On the other hand, I might do as well by drawing the pattern in ink and then cutting it by hand with a dremel. But where's the fun in that.

Side note: This is a good x,y platform for thin, flat objects that don't impose large side loads. I'm thinking cnc glass engraving, laser etching, ... any other ideas?


adam.bricker wrote 05/06/2014 at 00:19 point
I am not a machinist, but it looks to me like you might be trying to cut too deep on the first pass. I would use a sharper tool than a drill bit, cut less deep and run it slower if possible. Printer hardware isn't really designed for large forces and I think that's what is limiting your precision.

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