The CNC router has spent a couple of years in storage, too many other projects on the go. I finally got around to wanting to use it again, and decided to make a few changes to the original build.
First up, it was to BIG! It had a work area of 500mm X 1000mm, and this meant it took up an entire benchtop space of over 800mm by 1300mm. So I decided to cut the thing in half.
Then I turned it around, so the gantry moves along the Y axis now. Standing in front of the machine, the gantry moved towards and away from me. This made it a lot easier to see what was going on and change tools.
The original PC had died, so I picked up a 5 year old laptop for $80. The Laptop had a parallel port ( bit of a rarity these days ), and ran Windows XP, perfect. Once I removed all of the user installed programs, cleaned up the services, etc, it ran pretty fast. I installed a shareware copy of KCam to drive the control box and table.
Plugged it all together, and discovered the Z axis wouldnt work. It was using a KT-5191 half step stepper, and it had died, so I decided to borrow the Y axis M325 microstepper and use this for the Z axis. I ordered two new microsteppers from Ocean Controls, the DM432. Since I first built the CNC, microsteppers have gotten smarter and cheaper, and the DM432 is good value, at up to 40V and 3.2amps motor supply. With these fitted I had all 3 axis working.
While I was poking around with my CRO trying to sort out the dead Z axis, I did notice the step and direction signals were a bit weak, with marginal voltage and poor rise/fall times. Looks like the old laptop parallel port could use a little help to drive the microsteppers, so I bought a 4050 hex buffer from Jaycar, and used it to clean up the signals. Made a big difference to the signals.
The new microsteppers ran perfectly, so what next? The spindle motor.
The Ozito router was too dam loud, I wanted to route quietly, even if it means a little slower. I ended up using a 24V 300 watt scoota motor I had lying around doing nothing. Played around with belt and chain drives, but ended up going direct drive. The motor is coupled to a spindle I salvaged from a die-cutter with a short length of rubber hose.
I'm using a variable power supply to drive the motor. I would like a bit more spindle speed, but this setup works fine for now.
While I was at it, I changed the X and Z axis from chain drive to driect drive too, a lot quieter.
The couplings are made from some HDPE
Finally, the software. I decided to give Mach3 another go, the last time I had a few problems getting it working properly. This time, I got it sorted, and I was totally impressed! It really is fast, much faster than KCam, and as good as EMC2, but a lot easier to use. I was so impressed I bought a licence.
Below is an example of a mold I made on the rebuilt CNC machine.