Super X1 conversion - motor stalling

[bruce_miranda]

So I've finally got my motors running smoothly on the Mach 3 but I've hit yet another problem.

Every so often the motors will stall for no apparent reason. I first thought the lead screws where getting jammed but I've even tried the motors without any load and they still stall.

When the motors stall even if I try to help it to move forward it won't. But the moment I release the jog key and start jogging again it works fine.

Jog at slower speeds causes it to stall less but it does stall. Also when jogging at slow speeds I can hear the motor sometimes hesitate.

See the video or a fast and slow jogging X axis without it being connected.

http://www.youtube.com/v/e1wQHubSqFY

P.S> I don't know what's the BBCode to embed YouTube Videos in this forum.

[bruce_miranda]

Anyone with any help? I'm really getting desperate to get this machine going.

[Adamj12b]

It seems like you might have your velocity in mach3 set too high. try turning it down and see if that helps. Also, what is your kernel speed set to, and what are you using for motor drivers and power supply?
-Adam

[bruce_miranda]

If I jog at 35% too the motor stalls. Kernel is set at the lowest 25K, PSU is a 40V 10A with the motors driver in parallel and drivers are the Motion Control Products MSD542.

[bruce_miranda]

What are the signs of the PSU not being able to take the load of a motor? Or if a driver is reaching peak which is lower than what the motor is demanding?

[Adamj12b]

Another question. Dose this happen on all axis' or just the X? As for the power supply, when you are overloading it it will get hotter quicker, and the voltage will drop due to saturation of the transformer. What are the motors you are using? Are these bipolar or unipolar drivers? I looked at the page about them, but it says its a chopper driver which I thought was only unipolar, but then goes on to mention bipolar also. -Adam

[bruce_miranda]

Happens on all Axis, what is also strange is that sometimes when I jog two axis together they will stall together too.

I'm using the following motors
http://www.motioncontrolproducts.co....TH76-2808B.pdf
and following drivers
http://www.motioncontrolproducts.com/download131.html

[alexccmeister]

I have the same problem with my stepper motor. But it stalled only when I set the velocity too high. Its ok when set to 60IPM. Faster than that and it stalls. I am getting a 48V 10.5A PSU to see if I can rapid faster without stalling. But looking at the speed of the revolution. Its really fast. That will be too fast for the X1 table. I think to rapid at 100IPM on an X1 or X2 would be more than sufficient. The speed you set may be higher than that.

But I could be wrong. I am trying to get about 100IPM with my new PSU without stalling. If that happens, I am very happy.

Alex

[Adamj12b]

OK, a few more questions before I give you an answer. What are the steps per unit you have set in Mach 3? Also what do you have the drive set to for micro stepping?

On another note. I believe you said before that the motors were wired for bipolar parallel. Looking at the spec sheet, the motors have an inductance of 1.6 mH. Using the formula [optimal drive voltage = (sqrt(mH))*32) gives 40.47 volts. You might want to keep an eye on the motors to make sure they are not getting too hot. They will be running at the top of their range.

-Adam

[bruce_miranda]

I've used the 2 micro step setting on the Driver. The motors are running absolutely cool no problem there.

My Mach3 is set to MM units and at 1000 step per mm for the x and y axis at Velocity 600mm/min and acc of 200

As mentioned, slow or fast job results in the same thing except at slow jog it stalls less often than at fast jog.

[Adamj12b]

When you jog multiple axis' dose it do it more often? If you try jogging all 3 dose it do it real quick?

What it sounds like to me is that the computer is having of trouble outputting the pulses. If the computer was telling the motor to turn one direction and the direction pin flickered this could cause the stalling. It would try to change directions so fast that the motor would lose it and go into a stall.

What is the computer that mach3 is running on? -Adam

[bruce_miranda]

its a Dell Latitude laptop D800, that has been freshly rebuilt as a Standard PC and the Driver Test shows a nice clean line. Its 1.7GHZ and got 2GB RAM.