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View Full Version : THC bounce



stirling
05-24-2010, 10:36 AM
THC300, Mach3, THC300SM3 screenset (fixed). Set the THC speed high and it bounces like crazy, turn THC speed down and it calms right down and is usable. BUT it's still oscillating, allbeit with small amplitude - maybe a mm or so. So question: What frequency does Mach poll THC up/down?

Thanks

manmardam
05-26-2010, 05:54 AM
i think is Better you adjust "THC RATE" to %10

Amir

stirling
05-26-2010, 08:49 AM
Hi manmardam - Certainly a low THC rate calms the oscillation down but you have to compromise otherwise the head won't move fast enough. The reason I'd like to know the THC up/down input POLL rate of Mach is that at the moment I think the bounce is due to Mach being too slow in this respect. What seems to be happening is that Mach overshoots all the time because it's not reading the inputs fast enough. Whether I'm right I don't know but my feeling is that if (say) Mach was reading the up/down between every step pulse, it would be spot on all the time and would be able to react in real time. I suspect in reality Mach is reading the inputs at a much lower frequency than step frequency.

manmardam
05-26-2010, 09:45 AM
what version of MACH are you running?
and are you use THC300 ?

Amir

stirling
05-26-2010, 10:25 AM
THC300, Mach3 Version R3.042.020, THC300SM3 screenset (fixed)

manmardam
05-26-2010, 11:11 AM
are you adjust Z axis settings correctly ?
i mean: Velocity/Acceleration

stirling
05-28-2010, 03:50 AM
velocity and THC rate I've covered and acceleration of Z doesn't figure in THC.
But my question is: Does anyone know the polling frequency of Mach's THC up/down inputs?