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Klipper3d / klipper

Klipper is a 3d-printer firmware
GNU General Public License v3.0
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Klipper Stopping on FAST moves. MCU limit or bug? #427

Closed Maglin closed 6 years ago

Maglin commented 6 years ago

There was a recent change to my Z which increased its resolution considerably. One the first leveling it stopped on a 100mm/s Z/X/Y move. This is one MCU running 4 Z steppers and the other MCU running 2 X/Y steppers. I'm including the log files. I did it several times and found if I move my Z faster than 50mm/s now it does this. I issued an M112 after each event so it's in there a few times.

Klippy.log

edit: I just relooked at my logs and it is just attempting to go over the step rate of that MCU. Is it possible to have the MCU lock all 4 steppers in sync and just send a single Z command once the gantry leveling has been accomplished? This thing is capable of going much faster. I know I can put it on better hardware and that is still a WIP.

grigorig commented 6 years ago

You have: MCU 'z' shutdown: Rescheduled timer in the past This is a typical sign off hitting the MCU step rate limit.

KevinOConnor commented 6 years ago

As indicated, the requested step rate is too high for an atmega2560 (with your config a Z move of 100mm/s would be 160K steps/s). I don't think it would make sense to attempt to engineer a software solution - it would be high effort, high risk, and there'd be little reward given there isn't much call to move the Z that fast.

-Kevin

Maglin commented 6 years ago

Thank you for the reply. I was just asking. I would like my Z hop to be as fast as possible. In a few weeks, the SAM4E will be running klipper. I'll be using that before too long.

hg42 commented 6 years ago

if you have a high gear ratio, you might reduce the microstep setting. Usually the resolution is much too high for Z.