I needed to figure out the problem with racking in X (you can see it if you look closely at the video). Turns out that my initial suspicion was correct; the sprockets had been twisted relative to each other while I was installing the chains, so all I had to do was let the tension off the sprockets (by loosening the grub screws), then re-tighten them in a known position (with the gantry seated against the chain mounts, the physical “stop” at the end of X), and that fixed it.
I also wanted to work on the axis speeds in Mach3; I set them to:
889 steps/inch
800 ipm
25 acceleration
for both X and Y, and I hadn’t messed with Z, since it’s the same setup as I had before (13 TPI screw).
The new parameters make the axes move fairly quickly, but stop pretty quickly when I let up on the keyboard. Patrick (the designer of the machine) had suggested a very low acceleration in the 5-15 range, but that makes the machine keep going for a noticeable (2-5 seconds!) after the keypress stops. That often causes me to run into an end stop, and seems like generally a bad idea.
I didn’t have time for a full calibration workup, actually measuring the move distance and calibrating the steps/inch accordingly. However, I did confirm that the machine will move more than 48″ in Y. Nifty! I also confirmed that there is about 105″ of room in front of the endmill when it’s at X=0, but I was unable to move the full distance, because the computer is in the way. I’m going to have to figure out how long the motor cables need to be in order to properly run the machine, too.
The machine did a fine job at handling long and accurate (or at least as accurate as I was measuring) rapids; I gave it G0Y48 followed by G0Y0 and it did the job.
I got the endmill installed into the router, but I am going to need to push the router down in the mounts a little, because it’s impossible to get to the collet nut to tighten it properly.
I need to get a good full-axis measurement for Z. With the Z leadscrew from the Book Machine, I’ve definitely got enough length to make Z move to the limits of running itself off the rails at the upper end and running the vacuum shoe into the table at the lower.
I need to get the lower shelf put in, at least enough of one so that I can move the computer down there. I also need to scrounge some longer ethernet cables; I think that Y and Z will need at least 12′ in order to work.
I started looking at where I’d put in home switches. That will be a decently big project, as it will take at least a soldering iron, and will also require me to open up the computer case to do some wiring, as I think it’s not hooked up yet. While I’m in there, I will probably hook up the Super-PID wiring also. To the extent that I can keep those two projects uncomplicated, I have a better chance of completing them.
I wonder in the back of my mind whether the 425 oz-in motor will be strong enough to move X around, or how soon I’m going to be upgrading. I spoke with Gecko about trying to drive a larger X motor with the G540, and it sounded like that’s unlikely to be straightforward.
The plan, as always, is just to start moving forward, and to see what happens next.
I should be able to make sawdust this weekend.