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Author Topic: Mach 3 velocity limit?  (Read 3859 times)

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Mach 3 velocity limit?
« on: July 10, 2013, 07:19:20 AM »
I am puzzled, once again.  I've just installed the gecko 201x, which at 10x microstepping, forces me to enter a value of 20000 steps per inch for my 10 tpi lead screw.  In trying to tune the motor, I notice that Mach 3 will not allow more than 75 ipm top velocity in its "velocity" field in the motor tuning section.  Is this the case?   
tony

Offline Hood

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Re: Mach 3 velocity limit?
« Reply #1 on: July 10, 2013, 07:24:05 AM »
The max velocity is limited by the steps per unit and the kernel you have set.
For example you have 20,000 steps per unit so at a kernel of 25KHz that would be 25,000/20,000= 1.25 units per second or 75 units per min.
Increasing the kernel to 45KHz would get you a max of 108 units per min.
Just be aware that the higher the kernel the more likely you are to run into issues with the pulsing, dependant on your computer of course :)
Hood
Re: Mach 3 velocity limit?
« Reply #2 on: July 10, 2013, 08:16:10 AM »
MMH...., I thought I had the kernel set at 35K. Let me check.  thanks
tony
Re: Mach 3 velocity limit?
« Reply #3 on: July 10, 2013, 10:15:15 AM »
I am trying to use the driver test, and notice that on start up, the default frequency it's always 25K. Without my hitting the timer start or stop button, the test begins.  I am confused about how to try other frequencies. If I use the timer start stop button, I get a "timer not counting" error.  I can , while the driver is "testing" change frequencies and see new frequency displayed on the very top of the window.
But my question is how does one use the timer buttons during the test, and under what conditions does the "timer not counting" pop up occur.
Mach 3 seems to work fine, but I am trying to figure out the proper testing sequence of using the driver test.

tony

Offline Hood

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Re: Mach 3 velocity limit?
« Reply #4 on: July 10, 2013, 04:31:27 PM »
Just click whatever frequency you wish to test when the driver test is running. I have no idea what the start and stop buttons are actually for as they do seem to screw it up.
Hood
Re: Mach 3 velocity limit?
« Reply #5 on: July 11, 2013, 09:56:04 AM »
Thanks, Hood. Things are looking better.  My 3 ghz pc is providing a smooth 35K kernel frequency, which is what the G201x liked better. One more thing: What is the "better" approach to the parallel board to gecko step and direction signals? to sink or to source them? I am currently sourcing the signal, but I am not sure if sinking the signal to a gecko is the preferred method-- for more stable performance.
tony

Offline Hood

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Re: Mach 3 velocity limit?
« Reply #6 on: July 12, 2013, 09:12:20 AM »
I am not sure about the G201X, I know some Geckos have a positive common terminal and some a negative, so will just depend what the 201x is.

Hood