Mendel + RAMPS speed reduction?

Hi,

Pronterface connects just fine, and if I issue commands, the motors just hum. I suppose the frequency is too high. In my test setup, I came up with a max frequency of 14kHz before the motors stall.

Sprinter 1.3.11T / 19.03.2012
RAMPS 1.2, pololu 4983

Temperature of the pololus is good.

Pin assignments are correct: if I do a series of digitalwrites to XYZE_STEP_PIN, the motors move just fine.

Now STEP_DELAY_MICROS and STEP_DELAY_RATIO are not used in the code.
Setting #define _MAX_FEEDRATE {4, 4, 2, 45} this low does not change things either.

How can I reliably reduce the speed or debug this issue?

AFAIK, Teacup is ths only firmware which limits the commanded feedrate to what the machine can do. There it's MAXIMUM_FEEDRATE_{XYZE}.

For all other firmwares: don't send feedrates that high.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanks!

Switched to teacup, positioning now works without tweaking feedrate. Teacup seems to step rather slowly: I could turn it faster than default.

Quote

I could turn it faster than default.

That's expected. Default feedrates are very low to protect the machines of users which don't care to adjust their config.h.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY