Here's what's been going on in the shop on the milling machine the past few weeks:
Feb 7, 2008
The timing gears that I bought seem to be a bit pricy ($16 for the large one, $9 for the small one) so I thought I'd try my hand at casting some from the originals in aluminum. I made a mold using OOMOO silicon. They turned out pretty good.
Then I made wax copies from paraffin wax. I'll be messing with investment and molten aluminum at a later date.
Feb 16, 2008
I'll be using an old computer case to hold the motherboard and the CNC controller as well as the power supplies.
Feb 23, 2008
Today was a monumental day! Alive! It's Alive!
I did a test run with a laptop (it didn't work - I had to scrounge together the parts for a PC) and laid out the CNC controller, connected the motors and it worked!
The computer set up:
The motors connected:
The machine cutting!
And for your viewing pleasure, a couple short videos. The first one drawing the famed 'road runner' GCode file that comes with Mach3, and the second one actually cutting the same pattern in aluminum.
It's pretty exiting, and just a little bit creepy, watching those hand-wheels turning by themselves.
I learned a couple of things from this test, the most important being that even with a 2:1 gear ratio, the 120 oz-inch steppers that I'm using aren't nearly powerful enough to run a full-size milling machine. I ordered new 305 oz-inch steppers from Hobby CNC last weekend and hope they arrive soon. I've already got plans in mind for a Dremel-powered mini router table using the 120 oz-inch steppers
I'm also only testing the x and y axis of the machine as I haven't made up the bracket to hold the motor for the z axis.
Feb 29, 2008
Tada! The bracket for the z axis. A few adjustments to make, but it's shaping up nicely.
I mis-measured the centre distance between the stepper motor shaft and the leadscrew shaft by 1/2" so had to adjust the mounting brackets. Nothing a little grinding, cutting and welding couldn't fix.
The capscrews I used for mounting the motor assembly to the milling machine with were a little too tall on one of the brackets, so I had to modify one of them. This one is the regular capscrew.
Off to the lathe with you!
The finished result, nice and low-profile.
The first stepper motor assembly on the x axis, assembled!
The y axis assembly.
Both assemblies, in all their assembled glory!
When I get the time, I'll be making tin shields to protect the motors and belts from flying chips. You can just see on the bracket a small capscrew that I've put on the top of each assembly. This screw will hold the tin shield in place but will allow me to easily remove it to adjust/replace the belts, etc.