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Author Topic: Just a general question…  (Read 1976 times)

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Offline Tweakie.CNC

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Just a general question…
« on: December 21, 2014, 07:35:57 AM »
Whilst using Mach3 with the Parallel Port - when running a stepper motor at a constant speed of 2000 rpm the pitch of the sound it produces, very occasionally, has a momentary slight change. Increasing the speed to 2500 rpm - this slight change of pitch ‘phenomenon’ generally causes the motor to stall.
Fitting a ‘dampener’ (in the old days, used to overcome ‘mid band resonance’) overcomes the stall and for the most part cures the problem (maybe fitting a suitable ‘flywheel’ may also work just as well).

I suspect that the aforementioned ‘momentary change of pitch’ is a glitch in the step pulse chain which may be Mach3 related or Windows related, I don’t know which, but I am wondering if anyone else has trod this route and has found any answers.

My next task will be to try an external motion controller and see if the ‘phenomenon’ persists but at the present it is all bit of a mystery.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Hood

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Re: Just a general question…
« Reply #1 on: December 28, 2014, 01:30:16 PM »
You should not get that issue with the external controller, if you do then it is something in your hardware between the controller and the drive, possibly noise.
Hood

Offline Tweakie.CNC

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Re: Just a general question…
« Reply #2 on: December 29, 2014, 01:23:52 AM »
Thanks Hood, I am sure you are correct.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline BR549

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Re: Just a general question…
« Reply #3 on: December 29, 2014, 02:13:55 PM »
Just a thought but check that the CPU is not changing speeds on you.

Been there on that one.

(;-) TP

Offline Tweakie.CNC

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Re: Just a general question…
« Reply #4 on: December 29, 2014, 02:19:00 PM »
Thanks Terry - I am not sure just how I do that but it something I never would have thought of checking.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline BR549

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Re: Just a general question…
« Reply #5 on: December 29, 2014, 04:13:01 PM »
I found it on a ACER PC, look at the task manager while you are running the AXIS steadly IF you see a different change in the graph at the same time the motor sounds change it may be that.

you can look in the PC Bios for anything involving variable CPU speeds. I believe they use it for power consumption control or something related. It had the OPTION to turn it off.

Just a thought, (;-) TP

Offline Tweakie.CNC

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Re: Just a general question…
« Reply #6 on: December 30, 2014, 02:25:44 AM »
Thanks again Terry – I will try that.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.