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### Author Topic: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time  (Read 516 times)

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#### dmoore

• 36
##### Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« on: May 10, 2020, 07:12:02 PM »
I am attempting to switch 4 CNC router tables from Mach3 over to Mach4 but one area I'm stuck on is the "Time in Seconds" period of an axis in which the velocity is applied.

Here in Mach3 you can see the period of time is 1 second (which works perfectly fine).

Here in Mach4 you can see the period of time is 4 seconds (which coasts too long after jogging).

How do I adjust the "Time in Seconds" period from 4 seconds to 1 second?

#### joeaverage

• 6,407
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #1 on: May 10, 2020, 08:57:15 PM »
Hi,
that is not a setting per se. The Mach4 motor tuning graph shows a velocity/time graph of the motor as it accelerates at max accel to max
velocity and then decelerates at max accel. The time scale is a convenient means for you to establish the time spent at each phase.

Try for instance to drastically increase the acceleration and see what happens to the time  scale. Try also much higher and lower max velocities and
see how the time scale varies.

Craig
My wife left with my best friend...
and I miss him!

#### dmoore

• 36
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #2 on: May 11, 2020, 01:18:47 PM »
Thanks for the reply.  While I don't know what the exact numbers for "drastically" are, I tried a number of combinations shown below and never could get a number (time frame) less than 4.0 seconds.  Can you possibly provide any specific numbers to get it closer to 1 second?

#### dmoore

• 36
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #3 on: May 11, 2020, 01:19:26 PM »

#### joeaverage

• 6,407
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #4 on: May 11, 2020, 06:16:09 PM »
Hi,
I have experimented with changing the speeds and it seems that the display is restricted to 4sec.

Remember that that is just a visual representation of the time/velocity diagram, not necessarily a practical movement.

My new build mill for instance travels 350mm (the X axis travel) in 1.6 seconds including both  acceleration and deceleration
phases, thus my machine will NEVER perform a G0 move of 4 seconds duration, and if it attempts to it will crash BIGTIME.

Craig
My wife left with my best friend...
and I miss him!

#### dmoore

• 36
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #5 on: May 11, 2020, 06:21:54 PM »
I have experimented with changing the speeds and it seems that the display is restricted to 4sec.

Thanks for your help!  So would you call this a "bug" since it doesn't actually represent the actual value even though the underlying value is actually changing?

Is anyone else able to get their motor velocity chart to show correctly as it shows correctly in mach 3?

#### dmoore

• 36
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #6 on: May 11, 2020, 06:28:36 PM »
I've put in a ticket with support and we'll see if we can determine if this is something I am doing or it is actually a "bug".

#### joeaverage

• 6,407
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #7 on: May 11, 2020, 07:00:01 PM »
Hi,

Quote
So would you call this a "bug" since it doesn't actually represent the actual value even though the underlying value is actually changing?

No, I don't consider it a bug at all. Its a graphic representation of a speed vs time diagram, no more, no less.

As I said my servo will cause my axis to accelerate up to max speed (15m/min) in 90 ms at which time it will be travelling at 250 mm/s. Clearly
it will have to decelerate and stop in short order so as not to overrun an axis of 350mm. The speed vs time graph does not include any limitation
due to finite axis length, nor is it required IMO.

Craig
My wife left with my best friend...
and I miss him!

#### dmoore

• 36
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #8 on: May 12, 2020, 10:15:58 AM »
The speed vs time graph does not include any limitation due to finite axis length, nor is it required IMO.

If the graph only provides an "overview" of the rise and fall of velocity, why wouldn't they just have removed the time reference?

#### Bill_O

• 365
##### Re: Switching from Mach 3 to 4 - How Do You Change Motor Tuning Time
« Reply #9 on: May 12, 2020, 11:10:14 AM »
dmoore,

I really hate to say this but give it a break.
You can clearly see in the graphs the time it takes to accelerate, followed by a max feed followed by a decelerate.
The times are all there.
Who cares if the overall time is 1 sec or 5 sec?

Sorry to be a jerk on this.

Bill