CNC Build – Back in the game!

I decided that I was going to figure out the sensor cable today, once and for all, one way or the other.

And, spoiler alert, I did.

I cut the zip ties and looked at the way the port is installed, and decided that Sugru wasn’t going to help. I reinstalled zip ties, but in a different configuration, and that seemed to work a bit with the new sensor cable.

Then, I started ohming out the cable, to make sure that I hadn’t messed up the DB9 port while pushing it around.

and I noticed that none of the top-row pins in the cable were registering. Yikes! I ohmed the cable all by itself, AND THE STUPID CABLE DOESN’T HAVE THOSE PINS HOOKED UP END-TO-END. Are you kidding me?!

So I ohmed out the original sensor cable (of course it works), and ohmed out the DB9 port (that worked too), and decided to just try the system with the old cable in place.

As I was poking around inside the PC case, I happened to notice that the BIOS clock battery was a 2032 (a variety that I keep in stock around the house), I popped a new one in, and then promptly failed to get into the BIOS upon next boot, so XP booted into Aug 2005 😐 But, there’s a fresh battery in, aw yeah.

I booted the PC again (setting the BIOS time this iteration), and was also able to see 5v on the pins I expected, nice. Then I brought up Mach3 and was able to see the “Home” pin flashing when I touched GND to the Home pin (I have all 3 home switches wired to the same G540 input — can’t remember why I did this, but I do remember it’s a thing).

I stupidly decided to plug the sensor cable into the Super-Pid at this point; I know I’m not supposed to plug stuff in when it’s up and running, but I decided to go for it. That turned out not to be a problem. The SuperPid turned on as soon as it got 5v, and I was able to hand-turn the router collet and see the spindle sensor working.

I spent the next little bit getting the home switches all registering again; I was barely to this point in the initial machine calibration process (kind of like polar aligning a telescope mount) when I stopped, but I do recall vaguely that the X axis was not homing properly, and this turned out to be the case again (or still). I retrieved a spare magnet from the kids’ whiteboard, and the sensor tripped right away. I stuck the new magnet to the already-installed one, and they clicked right together (because Magnet), and all of a sudden, I had home positions on all 3 axes! What?!

I turned off soft limits temporarily, clicked “Ref All Home”, and watched in wonder as the machine went and touched all 3 home switches. That was Very Satisfying.

I spent the next little bit remembering the relationships between “Machine Coords” and “Table Coords”, and what happens when you say “goto zero” if those aren’t the same, &c.

I ran the feed-n-speed test, and it of course wouldn’t run right at the origin, because of a soft-limit violation. But I offset the tool by 3″ in X and Y (and -0.5″ in Z), and it ran flawlessly.

I then plugged in the 110VAC mains side of the SuperPID, and made sure that it could start and stop the router, and change its RPM.

When I ran the test again, I was a bit surprised the first time to hear it changing the router speed in between each cut (although I shouldn’t have been — that was the whole point of the test 🙂 ).

I captured another video of the accomplishment (again, too big to post).

I need to get the CNC table cleared off so that I can actually put in a endmill and run the test “for real”, but I am happy to declare that the CNC machine is officially 100% back to where it was when I left off.

3 upgraded motor cables, and a bunch of careful testing, and I’m ready to roll again.

Success!

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