Well let's just say a stand alone 400 step motor transitioning 1000mm, yep 1 meter, in less than 50 seconds including a very long and precise velocity profile for start and stop allowing the same precision and vibration reduction as shown in the 800X videokaleun96 wrote:How fast are we talking? Just curious as I've had to order in some new pulley wheels to change the gear reduction from 1:2 to 1:1 on my rail as the Arduino + TMC2130 couldn't quite manage the speeds I needed, even with acceleration profiles. Though I only want the fast speeds for homing the rail, I don't need nearly as much speed for other functions.mawyatt wrote:The properly configured (not optimized though, so maybe more room) TMC5130 can run so fast I won't even post it, as you wouldn't believe me And it's quite and accurate....not a bad combination IMO
Some caveats to that are the Arduino's 16MHz clock speed, slowness inherent to the accelstepper library, and slowness inherent to the digitalWrite() function compared to the much faster Port Register manipulation.
My Pololu 1200 stepper seems to be capable of faster theoretical speeds than your more powerful motor (http://techref.massmind.org/techref/io/ ... timate.htm) but in addition to the limitations above I also have the 1:2 gear reduction (effectively making it a 400 step/revolution motor) and a small screw lead of 1mm. I think the fastest I could achieve without stalls was 7mm/s but including start/stop time over a length of 100mm you would need to add a few seconds for accel/deceleration.
I wonder if my upper limit is mainly determined by the Arduino clock and function speed or the inability of my motor to run faster under load.
Probably 1/3~1/4 the time taken up with profiled velocity for precision, not exciting resonances at start and stop, and low noise, so north of 20mm/s peak velocity
And it's very quite throughout the entire range!!
Since the effective "load" on the motor is very small with the THK rails I'm using (1mm pitch), I don't expect this to be much slower on the rail. Of course the rails aren't 1m long!! Now that I have the motor current waveform measurement capability I can optimize/tune the waveforms for the THK rails.
BTW I'm using a 15MHz effective clock from the RPi.