CNC Breakout Board Done

My latest board is designed, laid out, and hopefully safely in the hands of Laen over at Dorkbot PDX.

This is the main “breakout” board for the CNC electronics cleanup.  It connects to my fancy new Mesa Anything I/O FPGA interface card, and provides some protection and signal conditioning before connecting to the myriad of things that are needed to run the CNC mill: stepper drivers, spindle motor control, homing switches and other sensors, and the emergency stop circuits.

The size of this board is 4.000″ x 4.000″, and at Laen’s rates, it’s still fairly cheap – $80 – but it starts to be “real money” instead of $5 or $20.  Still, other than the other batch fabricators (most of which manufacture in China, under considerably less strict environmental regulations), you can’t get boards done this cheaply.  I think this is probably nearing the knee in the curve in terms of board area/cost for Laen’s service.  It’s a total no-brainer for small boards – there is pretty much no longer any excuse to hand-wire small stuff these days unless you really need it right that minute.  Laen’s service also has a lot of high end options that are hard to get at an affordable price from elsewhere: any board shape you want (routing), RoHS lead-free, ENIG gold plating (much of the time, apparently), 6/6 trace/space, 13 mil minimum hole size, high quality fab process, silk and solder mask top and bottom, etc.

Here it is in all of its technicolor glory.  I forgot how much of a pain it is to route 2 layer boards, especially power distribution.  With some creativity I managed to do it with some copper pours: the bottom of the board is all GND, and the top has an “L” shape of GND pour and the rest is VCC.  Will it perform as well as a 4 layer board?  Heck no.

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