We would really love to have a torque chart of the super power motors

Definitely! I haven’t gotten to chopper setting optimizations yet but I’m excited to get there

Yes! Me too :) One question--what is "affecting performance much" to you? Maintaining >1000mm/s travel speed? or maybe 500mm/s? or 300mm/s?

​​@eddietheengineer I want to be able to sleep in the room next to my printer without hearing my printer. At all. And have a full bed 2 inch high print finish overnight? I feel like these are metrics more people can relate to vs 1000mm/s vs 500mm/s

Well done, I love the way you present your data. Magnetic braking could be a good option for torque control. I suspect these test drive what the next round of test will look like.

@@stevehanwright481 thank you! I definitely considered magnetic braking, but decided against it due to not being sure if I could generate enough load at low speeds. Right now I’m working on refactoring the code to be more robust and reliable, since I’ve been getting some data collection failures that really put a damper in things 😄

This is a great question! It's really fascinating looking at oscilloscope data for stealthchop vs. spread cycle--it seemed like instead of keeping a fixed pwm frequency and varying the duty cycle, stealthchop varied the frequency? It definitely did not reach as high speeds as spread cycle. That may be a nice quick video I could talk through :)

Yes! This would be really cool! I'd love to be able to track motor rotational position/accuracy/smoothness and overlay that with the current characteristics and sound, maybe with that we could optimize TMC driver values to reduce sound, VFAs, etc

Ooh!! That’s a really great point, thanks for sharing! I’ll look into that

Yes! It's very similar to the OMC 2.5A motor shown in the initial results, both were essentially identical from a speed/performance standpoint. I need to try and compare the theoretical model stall to the dyno results! That would be a great idea

That’s great feedback! Do you have a datasheet (Ie 2209 or 5160) and page number for the reference?

Yes! That is an anomaly, it’s one of the things that is trickiest-sometimes there’s just a bad reading and I need to filter those out.

Yes! Are there specific models you would like to see compared?

@eddietheengineer the speedys vs the super power. The super has very low inductance. But so far, they are than the speedys in every aspect. They sound so much smoother and quieter... and shows less i think.

@@Vez3D We haven't been able to get any decent performance out of those super powers yet, the speedy's beat them in torque, i suspect they won't be very useful outside of extremely light setups? I've yet to try them myself, they're sitting here in a box though!

That would be fantastic if possible! I'm not sure what motor parameters/driver settings cause VFAs but if someone knows or has a hunch I'd be glad to do some testing to analyze it!

@@eddietheengineer I know that stealthchop made a huge difference in my v0 LDO motors but I think it's this kind of visibility and systematic approach what will make it possible to play with all the trinamic driver settings and see what they do empirically, not make blind, one-size-fits-all assumptions.

Definitely! Temps are a bit tricky since it takes so long to reach steady state--I wonder if it almost makes sense to create a model that attempts to plot the temperature of a stepper motor during a print by feeding in the motor power characteristics, heat dissipation characteristics, and the klipper kinematic log? Then you could predict how hot it would get for a given print/settings.

@@eddietheengineer ideal would of course be measuring the power as the delta between measured torque x speed, vs input power. Honestly just a reading after a min for a few would be good, because the lines don't matter if the temps are unsustainable. Regardless, this is all follow up - what you have is an amazing start.

Yes! I'm attempting to calculate mechanical power vs. input power to look at an "efficiency" too, but the losses there would be combined both between the stepper driver losses and motor losses as well. The tricky part with measuring after a few minutes is that it stabilizes on the order of 30+ minutes since I guess the mass is pretty large and the power is pretty low. Theoretically it may be possible to look at a "projection" of where the temps would be.

​@@eddietheengineer The motor copper windings may heat up faster than a thermistor on the outside of the laminations. You could add relays to isolate the motor and measure winding resistance change after running for say 0,5,10,15 minutes.

@@bdykes7316 I saw that the new TMC2240 drivers have estimated motor temp readings (probably from looking at change in resistance) which would help this too! Too bad the 5160s don’t have that 😄

Yes! I considered something similar, the tricky part though is that I need steady state stepper operation for a few seconds in order to capture all the datapoints, so it wasn't really feasible to do a transient test like that. However, to validate just the stepper motor torque that would work!

@@eddietheengineer maybe te resistance to the bldc motor coils could give more flexibility?

That's a good question! At this point I think adding a resistance between the coils would reduce torque (since they are shorted together now), but I can definitely change out the pulley on the BLDC motor to change the relative speeds of the two motors! One day I'll get the Texas Instruments motor controller working :)

That's an interesting point--I'd love to see the data sheets for the new Mk4 motors! I have tested some super low inductance stepper motors (like

@@eddietheengineer I have played around with the TMC spreadsheet's where you add the specs for the motors and it calculate new settings for the TMC drivers, but it doesn't seems to make any differences on the initial tests. So it would be interesting to see what settings Prusa have done compare with default settings, maybe I could learn something... 🙂

Hello Christian! I currently plan on uploading datasets to my GitHub repo. A bit part of this project is finding ways to easily process and digest the data because there is just so much of it!

​@@eddietheengineer No doubt. If you plan on using matplotlib,pandas or tools from scikit it should be no problem integrating either CSV, JSON or Dolt (SQL) for data storage. In fact I would expect SQL to be many times faster than the two others. I'll happily create a pull request to your project once you have the time to publish data!

Yes! This is one thing I want to check--basically comparing legacy drivers like the A4988 to newer generation drivers. I haven't done that yet though!

Yes! Once I get the variable load I can find the maximum torque value that each speed stalls at 👍🏼 then any load below that value should be okay

@@eddietheengineer awesome man! Keep up the good work 💪🏻

Wow! That’s very high amps. I have tried testing up to the rated amps (Ie, 2.5A for a 2.5A stepper motor). the rms amps at low speeds reach the target value, but they quickly drop off even at high input voltage due to the backemf.

@@eddietheengineer OMC told me that they use 3 phase steppers for high speed applications. I want to try them too, but drivers are quite expensive. But im happy with 1000mm/s (1500RPM) with normal motors, but i cant test them as you do, it looks really fast, but i cant tell if the values are real, cant test it as you do...

@@dromCZ that’s an interesting thought, BLDC makes sense! I wonder what the positional accuracy is vs a stepper motor

Yes! I want to upload them probably to Github, but I'm not sure at this point how to organize everything and track versions, since the stepper dyno code changes over time :)

Thanks for sharing! I’ll take a look

Search for @AlexKenis

I've also added it to the description so people can find his channel easier :)

You are correct! Two things are going on here, one is that I need to work on phase shifting the current vs voltage signal since there is a slight time delay for the current probe vs the voltage probe. Second, I tried (naively) to measure the voltage across the coil with a regular voltage probe…not a great idea 🤣 it didn’t go well. Now I’m only measuring half of the voltage if that makes sense. The cleanest way would be to use a differential voltage probe to measure it directly! But I didn’t want to spend another $200 on one since this test setup has already gotten quite expensive. The other option I believe would be to have a second voltage probe that’s ground referenced to measure the opposite half of the voltage. Do you have any other recommendations? Or maybe a spare differential voltage probe lying around by chance? 😉