I haven't finished it yet; but since posting last I've been busy. I did some redesign and re-cut all of the baltic birch parts - then redesigned the y- and z-axis motor mounts and routed them out of 1/4" x 3" x 3" 6061T6 aluminum angle. They're a bit more robust than the
3/16" two-piece originals, and the 1/4" stock let me tap all the bolt holes to eliminate a dozen washers and lock-nuts.I hacked the four-axis controller (I'm always nervous about cutting PCB traces and adding jumper wires to make it behave differently than the designer intended); and now two of the control channels are driven by a single pair of inputs - which ensures that the two x-axis motors will forever march to the beat of a single drum (and in the /same/ direction!)
I made up the four cables that run from the controller to the motors; and mounted the y- and z-axis motors. I installed a downloaded copy of TurboCNC on the shop PC and spent a day trying to learn enough to do a reasonably correct configuration. I'll probably be tweaking the operating parameters for some time, since I /think/ I'm only allowing the steppers to run at a little less than 2/3 full speed.
Today I coupled the x-axis (only) lead screws to their motors, plugged the data cable in to the PC printer port, started TurboCNC, took a deep breath, and turned on the power. Not even a wisp of smoke - and no hot wire smell. Phew!
I put TCNC in "jog" mode and told it to jog 10" in the +x direction - and it /zoomed/ exactly 10", with a smooth acceleration, steady full-speed (at a parameter-controlled maximum of 14000 steps/second), and smooth deceleration. My calculator says that by holding it back to
14000 steps/sec it's only moving at 175 inches/minute; but I think it'll handle 20000 steps/sec (250 inches/minute). I want to tell you though, that the 14kc whine was music to my ears!Feeling encouraged with this initial success, I told TCNC to run one of the sample g-code part programs. The program was to raise the router (+z motion), move to the starting point for a cut (+x and +y motion), lower the router to the cutting depth (-z motion), cut a 1" diameter circle (+/- x and y motion) at 10"/min, and return the router to the original position (-x and -y motion). Even though the y- and z-axis leadscrews weren't connected, I think it ran through the whole sequence correctly.
I was so wired I had to take the rest of the day off. Now I need to tear it all down for painting - then do a re-assembly and installation of a trim router to do some actual joinery.
Life seems good when things work the way they're supposed to. I /will/ post a gloat (with photos) when I've successfully cut the first dovetail joint.
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA