Can't make my printer run faster than 200mm/s

General Discussion
1

Basic Information:

Printer Model: Hand made CoreXY
MCU / Printerboard: Ramps 1.4 / Orange PI Zero 2
klippy.log
klippy.log (24.7 KB)

Describe your issue:

Hello. I built my CoreXY machine some time ago and it runs fine but now, just for fun, I would like to make it run faster with speeds 500mm/s and above, like it does for example KLP1.

I upgraded my motors with bigger ones with more torgue, upgraded my drivers (TMC2225 on X and Y running in UART mode), installed 24v power supply, even compared my config with KLP1’s one for any additional parameters I might have missed.
But depspite all of this when I print at speeds 250mm/s and greater there are skips especially at monotonic infill and travel moves.

I am honestly out of ideas, can someone suggest anything I missed to try?
Thanks

2

Where do you have the 1.5 amps for X and Y motors?
This seems too much for me and the respective TMC drivers.
What motors are you using that you seem to have copied the KLP1 config?
You might want to get rid of the hold currents as this might cause other issues.

Acceleration of 20000 might be too much for your mechanics and motors. How is it with below 10000 mm/s²?

You can set the movement speed in Mainsail and command the print head in X and Y and check whether this works already or not.

2 Likes
3

The log says TMC2208

For TMS2208 RMSmax is 1.2 A

https://www.klipper3d.org/TMC_Drivers.html#prefer-to-not-specify-a-hold_current

Also - if you absolutely want to have it - hold_current way too much off from run_current. Usually it’s 60% of run_current.

https://www.klipper3d.org/TMC_Drivers.html#prefer-to-not-specify-a-hold_current

Do yourself a favour: Instead of speed go on quality.

1 Like
4

Thanks for the reply, TMC2225 is not available in clipper and as far as I know it configures as TMC2208.
Ok, I will try to remove hold_current

5

This will likely not save you.
Both TMC2225 and TMC2208 are the same driver and both are spec’ed at max 1.4A RMS.
Apart from the fact that you are running them at 1.5A, this will need strong active cooling and heat-sinking or the drivers will start to misbehave.

Also, IMO the TMC autotune is crap but YMMV

7

Hello. I might’ve experimented with current, tried 1.3 amp also.
I copied only part of config from KLP1 mostly extruder and printer speeds and acceleration values.

I use 17hs6401 motors. It might be too much but then how KLP1 does this?
I tried 10000 mm/s² it skips not so often but skips nevertheless, I start to think can Ramps’s 8bit processor be the bottleneck here?

8

You are right 100% about your point on speed vs quality.
In my experience 100-150mm/s usually is a golden range for good prints.
This attempt of mine to achieve crazy speeds is just for fun

1 Like
9

If you wish to establish the limits of your hardware, I would highly recommend following this guide:

Ellis’ Print Tuning Guide - Determining Maximum Speeds and Accelerations

Note that you might need to tweak the referenced macro a little bit for your specific printer.

Separately, to reliably achieve 500 mm/s with 24V power supply you will need to select and use suitable stepper motors. Many steppers will not support such high stepping rates with 24V supply.

1 Like
10

I have an update, thanks to ReXT3D, I tested my velocity limits, I used this command:
TEST_SPEED ACCEL=20000 SPEED=500 ITERATIONS=50

I’v got very frequent error:

MCU ‘mcu’ shutdown: Rescheduled timer in the past

I tried to recompile mcu firmware using 500000 band instead of default one 250000. This reduced an error above greatly but did not eliminate it…

One thing I tried that eliminated skips and errors whatsoever on ACCEL=20000 SPEED=500 is setting microsteps to 8 instead of 16 and disabling interpolation i.e.:

[stepper_x]
microsteps: 8
[stepper_y]
microsteps: 8

[tmc2208 stepper_x]
interpolation: False
[tmc2208 stepper_y]
interpolation: False

That way SPEED_TEST flies without an issue and skips, but can one even print in 8 microsteps with more or less good precision without an artifacts?

Do you think, these results indicate that my motors are the limit or Ramps / Orange PI is?

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