3 Axis Foam Cutting Mill

3 - Axis Foam Cutting Mill - Part 5

More Debugging Controller & PC Testing

The PC power supply is one of those items that has a pile of parts that are too good to pass-up... Nice Metal Box with a cooling fan, switch, hydro line-in, nice bits of stranded wire with 4 wire standardized connectors.

Once opened there's quality heat sinks, numerous resistors, capacitors, coils, a PWM (Pulse Width Modulator) chip, diodes, a fuse clip, and a 7805 Voltage regulator...

The box and the 7805 were what I was after. The CNC Controller will be mounted directly in front of the fan, and I'd just popped the 7805 on the 2nd Controller.

The issue of shorts plagued the 2nd controller, and pointed to higher Quality Control on the PCB etching side.

This is the circuit brd from the PS, and it was indeed "dead". For a split second, I thought to myself... "I can fix this..." but to what end, I've been accumulating these things over the years, and have several that are working...

+5VDC @ 20Amps and +12VDC @ 8Amps is pretty reasonable for a device that typically gets thrown out with the system after being handed down over the years.

Beyond the fact that there were issues with each axis, I finally get the Controller running each axis in either direction off of the PC.

The 2Khz square wave generator is now a bench fixture and will be the basis of the manual jog system.

The neatest issue I ran into was a short between the Y Direction term and the Z Step Term. The result was a locked Z, and a uni-directional Y motor. The bench test only checked for spin in one direction...

Now that I know the controller end is ready for real testing, I've started to think about the physical mill.

These are a set of end-bearing blocks for the lead screw assembly. They are simple and hopefully functional. They are to be casted this coming weekend.

Standard white bead foam from a shipping container, cut to rough size and drilled with a 7/8ths spade bit. once casted, the corners will be drilled and a set screw to fix the bearings into place. The bearings are from a SkateBrd repair kit and was under $20 a few years ago.

Support theworkshop.ca

Back to Machining