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Author Topic: Motor Tuning Help  (Read 2790 times)

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Motor Tuning Help
« on: December 12, 2011, 03:46:56 PM »
I need some help. I have been trying to get my router table to run for some time now, embarrased about the actual time. I cannot seem to get my stepper motors to run smothly while in program at all. I also got stuck trying to get a 20 yo machine to run again. I have a new computer running Mach3 software with bran new stepper motors, breakout boards, and powersupplies.

The issue I am having is that my motors, no matter how I have them tuned, Fast, slow, or otherwise. will not run in program. They will slip, grind, or jump while in the middle of a movement. It is not a contant thing either. I have run a drilling program where everything was perfect for the first 200 or so holes, then BAM its off for one reason or another. How do I fix this issue.

I have 1.8°, 200 step, 7.8 amp motors, NEMA 32 with a driver set to 10 microsteps.
My steps per is approx 390 velocity 3048 and accelll about 250.
I use MM increments.

Re: Motor Tuning Help
« Reply #1 on: December 12, 2011, 04:37:44 PM »
what stepper drive are you running?

is the machine binding? twisting casing the motors to loose steps?
any change that the coupler between the motor shaft and the lead screws are slipping?

what kind of lead screws?  acme screws with plastic backlash nuts?  (I have had acme screws get worn in the center of the screw and anytime I tried to move outside of the worn section of the screw the backlash nut would stall the motor because it had adjusted itself to the worn smaller section and bound up when it tried to go over the larger non worn section.

Re: Motor Tuning Help
« Reply #2 on: December 12, 2011, 04:42:05 PM »
 Hi Airplane Guy,
your settings will result a screw lead of 5.128 mm
If the lead is 5mm you will have 400 steps per mm
your steps per unit must exactly match
Alex   :)
Re: Motor Tuning Help
« Reply #3 on: December 12, 2011, 05:20:20 PM »
I am using an Mondostep 7.8 Bi-Polar Stepper Driver. I know the machine is not binding or twisted anywhere. I have leveled it, and re-built the gantry. So I know there is no mechanical issues. If I am thinking about this correctly, I don't have a lead screw, my table is cable driven.
Re: Motor Tuning Help
« Reply #4 on: December 12, 2011, 05:24:38 PM »
I am thinking its a pulse problem maybe, my time to int. stays at about 6.7 to 7.8 while running a program or not. Also, I have ran a pulse test. It tells me it is at excellent but if I were to move a small inner window, it will change to pulse too slow. How would I fix these issues?
Re: Motor Tuning Help
« Reply #5 on: December 12, 2011, 05:48:56 PM »
I do not have much experience with pulsing problems.
Did you optimized your system for mach ?
try 25Khz kernel speed.

Offline pplug

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Re: Motor Tuning Help
« Reply #6 on: December 13, 2011, 08:07:48 AM »
Try using a separate video card. The video card built on the motherboard can slow the CPU and create problems for mach. you could use one of the cheapest video cards out there and still get good results. 
Re: Motor Tuning Help
« Reply #7 on: December 13, 2011, 09:09:41 AM »
I can't install a seperate video card, no room for on in the computer I have for it. I have optimized it to run only mach. I will give that a shot today.