First Build 5 x 12 Steel Frame CNC router

**Boyan Silyavski** · 12-12-2016

Are you sure about that acceleration? My machine is tuned at 3000mms2 and is much snappier at 10000mm min feed rate. And from servos is still on 50-60% of their ability. Frankly when working at around 16000mm/min it looks really dangerous and leaves you no time for any reaction.

**Scott Damman** · 12-12-2016

Originally Posted by Boyan Silyavski

Are you sure about that acceleration? My machine is tuned at 3000mms2 and is much snappier at 10000mm min feed rate. And from servos is still on 50-60% of their ability. Frankly when working at around 16000mm/min it looks really dangerous and leaves you no time for any reaction.

No I am not sure, its very possible your machine is snappier I will have to take a look at your video, pretty hard to compare on video I suppose. Anyway, I was just going based on the settings in Mach that I had in at the time, quiet difficult to confirm at what speed its running. Also I was just jogging at a % of max (I am not sure if that % reduces both the feed rate and the acceleration) If both then what the video shows would be slower...

**Boyan Silyavski** · 13-12-2016

Originally Posted by Scott Damman

No I am not sure, its very possible your machine is snappier I will have to take a look at your video, pretty hard to compare on video I suppose. Anyway, I was just going based on the settings in Mach that I had in at the time, quiet difficult to confirm at what speed its running. Also I was just jogging at a % of max (I am not sure if that % reduces both the feed rate and the acceleration) If both then what the video shows would be slower...

I agree, its difficult to guess from video. All I was saying that you have to check that acceleration in Mach3, the plugin you are using and the drives. If either one of the 3 is set differently then its the lowest value active in reality. Though i dont know CSMIO and if you have to set the acceleration in the plugin separately, so yo better check manual.

My motors are only 400w but i assure you when i raise the acceleration snappiness from the servos themselves, its like shooting a bullet. Thats the sound how machine starts and stops. In fact my problems when tuning were related to Undershooting, cause i was not brave enough at first. So problem was it goes to position fast and then you could see how the motors for a millisecond were further positioning it in place. So i thought i am Overshooting. Yes but No. When i raised the servo response this disappeared. So auto tuning did not work i my case. Also it would be better if there is a total gain adjustment which auto adjusts all details, instead of separately adjusting each parameter. Which by the way is well described on many places around the web, but i still fail to comprehend it entirely .