CNC circuit board cutting for a project
JasonDorie
Posts: 1,930
One of my projects is to make a clock out of a CDROM drive.· I'm going to spin the motor, use an optical sensor to measure the RPM and find the 'top of cycle', and then flash LEDs behind a CD with a slot cut into it to indicate the hands of the clock.
Here's a very old prototype to show the idea:· http://jasondorie.com/WordPress/?p=18
Note that the CD only has one slit cut in it - it uses persistence of vision and well timed LEDs to display the 3 hands at the correct locations.
That version used a sensorless brushless motor controller from a remote controlled airplane, but it doesn't always work properly.· Standard CDROM drives use hall sensors to accurately time the motor - the one I have does, so I thought it'd be fun to write a driver for it.· This is a great project for the Propeller, since I can use seperate cogs to run the motor and handle all the PWM & PID stuff independent of the hand timing, all without interrupts.
My first issue is that the motor/sensor board has a ZIF ribbon connector with 1mm spacing and teeny little wires, which aren't easy to hand solder.· I decided to make a breakout board to allow me to plug it into a breadboard for initial testing.
I whipped up a schematic / board in Eagle, and used the PCB-GCode plugin to produce the machine paths for my·DIY CNC router.· I honestly didn't think it'd be accurate enough, but I was pleasantly surprised.
The vid isn't very exciting, so skip to the end to see how small the thing is:· http://www.youtube.com/watch?v=PPPoKnK6aiY
It's a simple board, but it's the first thing I've cut with traces this small, and it works like a charm.· Next up is an RC timer circuit to measure the sensors.
Jason
·
Here's a very old prototype to show the idea:· http://jasondorie.com/WordPress/?p=18
Note that the CD only has one slit cut in it - it uses persistence of vision and well timed LEDs to display the 3 hands at the correct locations.
That version used a sensorless brushless motor controller from a remote controlled airplane, but it doesn't always work properly.· Standard CDROM drives use hall sensors to accurately time the motor - the one I have does, so I thought it'd be fun to write a driver for it.· This is a great project for the Propeller, since I can use seperate cogs to run the motor and handle all the PWM & PID stuff independent of the hand timing, all without interrupts.
My first issue is that the motor/sensor board has a ZIF ribbon connector with 1mm spacing and teeny little wires, which aren't easy to hand solder.· I decided to make a breakout board to allow me to plug it into a breadboard for initial testing.
I whipped up a schematic / board in Eagle, and used the PCB-GCode plugin to produce the machine paths for my·DIY CNC router.· I honestly didn't think it'd be accurate enough, but I was pleasantly surprised.
The vid isn't very exciting, so skip to the end to see how small the thing is:· http://www.youtube.com/watch?v=PPPoKnK6aiY
It's a simple board, but it's the first thing I've cut with traces this small, and it works like a charm.· Next up is an RC timer circuit to measure the sensors.
Jason
·
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