Servos loose steps-Goes to Reset- I think??

[Mike 1948]

I'm not a electronics type so bear with me. I have a 2 1/2 year old DynaCNC plasma/router with servos, using Mach 3 as a controller. When using my 3 HP milwaukee router with a 1/4 inch flat bit the servos drives seem to loose steps or something and the machine go to "reset". I was using a flat 1/4 inch bit at 100 ipm .16 depth of cut about 20,000 rpm, full width cut.
The original setup from Dynacnc said all the controller knobs for the servos are to be set at the 11 o'clock postion. After talking to a one of the letgo tech guys from dyna he said I could turn the power up to the 2 oclock position and not hurt anything. I did that, but did not set redo the damp or gain knobs. I am still getting the reset condition though.
Any thoughts, do I need to resetup the motor controlers, how?? Or is 50 ipm the max I should be able to run with a 1/4 inch bit at that speed and feed. I would think that 100 ipm should be a problem.

Thanks guys
Mike

[Torchhead]

Mike: What controller on the DYNACNC setup? If it is one of our complete controllers (grey fiberglass box) with the red estop button on the front then I can help you. The power supply itself has an overload sensor and will shut down, BEFORE there can be damage to the drives or motors. If it's shutting down from a drive fault rather than a power overload it's doing to take some detective work. Some models we provided had a row of diagnostic LED's inside the controller. If it's one of our power supply/controller boxes then contact me direct or over on our Yahoo Support Forum.

TOM caudle
www.CandCNC.com

[Mike 1948]

Originally Posted by Torchhead Mike: What controller on the DYNACNC setup? If it is one of our complete controllers (grey fiberglass box) with the red estop button on the front then I can help you. The power supply itself has an overload sensor and will shut down, BEFORE there can be damage to the drives or motors. If it's shutting down from a drive fault rather than a power overload it's doing to take some detective work. Some models we provided had a row of diagnostic LED's inside the controller. If it's one of our power supply/controller boxes then contact me direct or over on our Yahoo Support Forum. TOM caudle www.CandCNC.com

Hi Tom,
Thanks for the offer but its a "Dyna" 6000 series controller, not one of yours. I don't think its a power issue as I was told it has a "upgraded" power supply from previous series controllers. I think the motors need to be set up with proper, power, gain and damp settings. If you or someone else could explain the procedured it would be greatly appreciated.
I would think I should be able to drive a 1/4 inch bit .16 deep at 100 ipm without faulting. Anyway thanks again.

Mike

[Torchhead]

Is there any indication in/on/from the box what is causing it to "trip". Servo tuning can cause drive faults but in my experience it takes some pretty mistuned drive to fault under that light a load. If it's G320 drives then you can set the current up to fully on if it's the larger servo motors they used. Then you are left with gain & dampening. To my knowledge they never tuned a drive. It went from the Gecko box to the controller and out the door!. The Gain and Dampening are inner active. Raise one and you have to rise the other. Tuning is a dance.

Drives only fault if they
1. Have a following/leading error > 128 counts. In other words the drive physics cannot keep up with the steps being issued by the software or the encoder count is wrong for the distance it has moved.
2. Have an overload.

You can get drive faults on servos if there is noise on the servo feedback wires. It "lies" to the drive and tells it the motor shaft is moving (and out of position) compared to the steps being sent.

Can you make it fault by jogging fast then changing directions? Can you fault it with G-Code doing some rapid moves back and forth? can you fault it when you jog two or three axis at the same time?

You may be surprised and find you are dealing with a noise problem.

What is your acceleration set to on each axis?

Wish I could be of more help. We try to help the CNC Orphans.

That's about all I can think of.

[Mike 1948]

Hi Tom and anyone else reading,
I tried to get the machine to fault by jogging but it ran perfectly. It seems to "reset" only under load. The motors seem to have alot of power standing still and trying to move them by hand.
It has Gecko G320 drives and MCG servos #33004 rated for 14.1 in/lb at 7.8 amps continuous. I remember someone posting(somwhere, some time ago) on how to tune these drives by "ear" , if anyone could link me to that post or explain the procedure it would be greatly appreciated. Right now the power setting is about 2 o'clock, with damp and gain about 11 o'clock on all three axises. At rest, one drive humms all the time, one drive is quiet, and one humms, quiet , humms, quiet.

Thanks
Mike

[Mike 1948]

Originally Posted by Mike 1948 Hi Tom and anyone else reading, I tried to get the machine to fault by jogging but it ran perfectly. It seems to "reset" only under load. The motors seem to have alot of power standing still and trying to move them by hand. It has Gecko G320 drives and MCG servos #33004 rated for 14.1 in/lb at 7.8 amps continuous. I remember someone posting(somwhere, some time ago) on how to tune these drives by "ear" , if anyone could link me to that post or explain the procedure it would be greatly appreciated. Right now the power setting is about 2 o'clock, with damp and gain about 11 o'clock on all three axises. At rest, one drive humms all the time, one drive is quiet, and one humms, quiet , humms, quiet. Thanks Mike

Ran a search and found some info.

Thanks
Mike