Messages

3491

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 09:15:25 PM »

Hi,
OK....well in absence of either an index signal/encoder or more useful outputs from your VFD then a fixed delay
along the lines you have proposed seems like the only solution.

I think you should be able to get the post processor to generate the required delay code rather than having to manually edit your
code.

Craig

3492

General Mach Discussion / Re: XHC WHB04B-6 Pendant unresponsive?

« on: November 18, 2018, 09:08:50 PM »

Hi,
regrettably many Chinese manufacturers do not respond to after sales requests for support.

Is there a particular feature or reason that you chose this device?

Craig

3493

General Mach Discussion / Re: XHC WHB04B-6 Pendant unresponsive?

« on: November 18, 2018, 08:08:05 PM »

Hi,
what does the manufacturer say?

Craig

3494

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 08:06:05 PM »

Hi,
one possibility is to use multiple ranges. Each range is the equivalent of a gear ratio.
I know you don't have a gearbox but imagine you set up three ranges with contiguous speeds:

range 0 0-3000
range 1 3000-9000
range 2 9000-18000

Then you could also set three acceleration times. If Mach scales the acceleration time within one range it probably wouldn't matter.

If think your post processor should generate the code required to cause Mach to change gear automatically.

Craig

3495

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 07:40:27 PM »

Hi,
so whats wrong with the Accel Time and Deccel Time that Mach provides for?

Craig

3496

Mach4 General Discussion / Re: Mach 4 not following toolpath

« on: November 18, 2018, 04:30:18 PM »

Hi,
I am not familiar enough to offer any advice on the adjustments you can make to the CV tuning.

We have max speed at 190 IPM, max acceleration at 6 IPS^2.

There is your problem right there....that acceleration is way WAY too low. That's what causes the deviations that you have noted.
You can reduce the toolpath speed and you describe increasingly accurate results. This comes about because the max acceleration
becomes a significant fraction of your max velocity.

6/50=0.18 or 12%
6/190=0.031 0r 3.1%

You will get the same results at 190IPM as at 50IPM currently IF you can increase the acceleration to 12% of 190 ie 22.8 in/sec².

CV is trying to make the best of your machine.......no doubt you could tune the CV feature to do a better job but you could address the underlying
problem......lack of acceleration.

Craig

3497

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 04:15:33 PM »

Hi,
looking at the S30 website suggests there is s version with a 200 line encoder. Does your spindle have it fitted or can you do so?

Craig

3498

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 03:24:25 PM »

Hi,
do you have a spindle index signal or could you fit one?

The reason I ask is that there is a convenient feature that you could use....'Wait for Spindle Speed to Stabliize' found in
the Configure/Control/Spindle tab. If it is checked the Gcode will pause until Mach detects that the spindle speed is up to your nominated
percentage of its final speed. It has the advantage of 'minimum wait'. That is if you specify a delay of 15 secs to 24000 rpm which may be
adequate for a moderate diameter tool of moderate inertia but the delay is more than required if you were using a very low interia
small diameter endmill say. This feature waits only until such times as the spindle is up to speed and then continues processing GCode.

As Chas has pointed out there is are two signals defined in Mach4; ISIG_SPINDLE_AT_SPEED and ISIG_SPINDLE_AT_ZERO.
Note the signals are defined but they have no standarised action, you have to code how you wish your machine to operate in
there presence. Also the signals are supplied by your VFD. They are very common, maybe even standard, on all VFD's I have come across.

This last fact separates the two approaches:
1)Wait for Spindle to Stabilize.....Mach measures the actual speed from an index signal
2)ISIS_SPINDLE_AT_SPEED etc is supplied by the VFD.

Option 2) requires you to code the response of your machine whereas 1) does not....Mach's response is standardized.

Craig

3499

Mach4 General Discussion / Re: Spindle Accel/Decel wait times scale??

« on: November 18, 2018, 02:18:49 PM »

Hi,
could you not just tell Mach to accelerate at a very high level, effectively infinite, your spindle would accelerate at the rate determined
by those settings you have programmed in to the VFD?

Craig

3500

Show"N"Tell ( Your Machines) / Re: Controller and drivers

« on: November 17, 2018, 08:21:44 PM »

Hi,
the DYN4 servo drives have 320VDC link voltage which is derived from 220-240VAC single phase.

Craig