The latest test is a loop something like:

Travel 8000 steps forward

Travel 8000 steps backward

double the speed and repeat (until the max-speed)

The 'oneAxisHolder' takes in a single byte at a time on its UART, representing -128 to 127 *steps* away from where it's at currently. So "speed" is entirely a factor of the transmitter, in this case a bash-script on my computer. I set it to send one byte at a time, at, as I recall, 0.03 seconds (which is *just about* the limit at 4800baud). There's some slight stuttering, as mentioned in the previous log, which I *believe* to be due to buffering on the computer-side... I've run into this one before, and never noticed it when controlled by a dedicated [micro]controller.

Adding oil to the screw-shaft was *definitely* an improvement... At the end of the last log/video you can hear some scraping. And, at high-speed the binding was so great at times that the motor would even stall (?!). That binding, grinding, scraping, and stalling has all but vanished even at high speeds with just a little motor oil.

Now it "buckocks" like a chicken... Interesting that hadn't been noticeable before.

On the closer rail, the glider is firmly physically attached to the carriage. At the farther rail, the glider "floats" in a little slot on the carriage (rather'n a hole). I think they do this so that the two rails don't need to be perfectly parallel (which was certainly appreciated during assembly!). The end-result, it seems, is that the carriage rides along the stationary floating "glider" until it hits an end-stop that causes the glider to move with the carriage. Thus... "Buckock!"

I'm hesitant to add oil to that part, but maybe unjustifiably so. The thing is, the gliders appear to be fiberglass... And for some reason that to me means somewhat permeable, which I suppose could mean expansion, which could be bad considering as it stands the gliders are *very* tight on the rails. This is all hypothesizing, on my part... Wisdom, anyone?

And, again, the 'oneAxisHolder' is quite handy for experiments like these, but doesn't quite suit [one of] my end-goal[s], which requires two motor/encoder pairs, one of which is to be used as a hand-lever.

So, on to designing the next circuit... plausibly for two axes... And doing-so has gotten side-tracked again into the [plausibly] "Ridiculous" realm... I'm experimenting, again, with using audio-amplifier chips to drive my motors. https://hackaday.io/project/8348-random-ridiculosities-and-experiments/log/29597-audio-amp-motor-driver-class-b-this-time (If you're looking for really cheap high-current audio-amps that could plausibly be *each* used as *four* motor-drivers, check that link, quick... Sale Ending TODAY!)