I know there are a lot of variables in this and different printers are

I know there are a lot of variables in this and different printers are tweaked different ways, but what is the approximate speed of the x and Y axis?

I see a lot of issues people have with slack or stretching belts. What about using some type of screw drive for those too? They would have to have a higher pitch like for example multi start/fast travel/multi threaded acme rod. I know it would end up being a cost that is more, but it would result in better consistency. I know that’s how all the big machines at my work operate…

Makibox uses multistart leadscrews for X and Y. It seems to work, but it will never be one of the faster printers. Friction and step rates are high compared to a belt drive.

IIRC, @Richard_Horne has a ballscrew printer, but that’s a lot of mass (and rotational inertia), so I’m sure it has much beefier motors and probably still doesn’t have great acceleration rates.

Speeds depend on a lot of factors, but you’ll have print quality problems if you try to print too slow, which makes cheap threaded-rod X/Y drives a problem (10-20mm/s is probably a minimum). Depending on materials, temperatures, etc., the process will handle very high printing speeds, higher than any of the current bots can handle. I’ve successfully printed at over 300mm/s, but this seems to be the approximate limit for speeds that the common cartesian systems can achieve (at least with the current electronics, hopefully ARM will make higher step rates possible soon).

thanks I have been doing a lot of searching and it is hard to actually find an rpm rating for the standard nema 17 motor. I was just going to do some math to find a max, but no… lol

Most NEMA17 motors are 200 steps/revolution. How fast they can turn depends on the current to create torque, supply voltage to overcome phase inductance, smoothness of driver’s the waveform, and the step rate delivered to the driver. The speed that the motor is capable of turning depends on the driver circuit and control logic, and will also be limited by the motor’s torque vs. inertia and other resistance forces. In short, rpm rating for a stepper motor would be pretty much meaningless, as they’re designed to control position, not speed. Speed, in the case of steppers, is best thought of as a rate of change in position, unlike most motors for which position is better thought of as a function of speed and time.

yeah I read that. I guess I was just hoping to see a max not theoretical limitless. Once I saw numbers in the thousands from some peoples experiences, I decided the answer was:
circumference of the pulley * fast / 60

Well, if we assume that the rotor magnet is about 20mm across, if you take it up to about 2.9*10^11 RPM, the outer edge will be moving at the speed of light. How’s that for a theoretical limit? :stuck_out_tongue:

I am calling CERN…

@James_Kasper_CBWP Atmega based electronics do good till 30kHz (30 000 steps per second), arm based solutions do more. Most of stepper drovers peak between 75kHz and 200kHz. 30kHz at 1/16 mirostepping means 1875 full steps, or 9.4 rps. With 20 tooth T2.5 pulley it means 469mm/s top speed. Thats feedrate 28125

that is very useful thanks @Vaclav_Hula

@James_Kasper_CBWP Good stepper dealers will supply you datasheet, where you can find out things like “For SX17-0905 at 48VDC/1.2A, driven by driver with low jitter, you can expect 0.46Nm torque till 5rps, which then drops to 0.2Nm at 15rps and there our graph ends”. Nobody expects you to do lot more than 20rps with stepper drivers