Seperate X,Y,Z,A operation accelerations?

math_indy · Posted at 2018-10-3 05:14:13

I am automating a surface grinder which has vastly different control ratios on its three axes and therefore needs significantly different (mm/s^2) accelerations for each axis.

I got my DDCSV2.1 working well in CONT and MPG modes by tuning M_Ctrl accelerataion and deceleration parameters #45,#46,#47,#263,#264,#265.

Now that I try to run G-Code driven automatic operation I noticed that X,Y,and Z axis all seem to accelerate under the single mm/s^2 acceleration value in parameter #99 (operation acceleration).

Is there any way that I can seperate "operation acceleration" for X,Y, and Z axis while running from G-Code?

For example, I use these axis-specific accelerations which work great in M_Ctrl mode but, for automatic operation, I am forced to set parameter #99 to the least of these (2.0 mm/s^2) which results in a VERY slowly accelerating X-axis:

X: 150 mm/s^2
Y: 7.5 mm/s^2
Z: 2.0 mm/s^2

TOM

ytliu · Posted at 2018-10-6 06:29:37

math_indy Posted at 2018-10-5 22:59
OH WOW--MUCH BETTER!

I installed custom version 2018-10-04-XXX and now I have the accelerations tha ...

Don't worry, if there is no problem with this change, I will add it to the subsequent official version.

ytliu · Posted at 2018-10-3 07:58:07

I understand your request, I will try to change the software, but I am not very sure to solve your problem.

Can you upload your settings and gcode files to the forum?This will make it easier for me to test。

ytliu · Posted at 2018-10-3 07:58:21

I understand your request, I will try to change the software, but I am not very sure to solve your problem.

Can you upload your settings and gcode files to the forum?This will make it easier for me to test。

math_indy · Posted at 2018-10-3 22:33:09

On this surface grinder installation the DDCSV2.1 works great in CONT and MPG but inability to have axis-specific accelerations in automatic processing mode (GCODE) may be a serious problem for my project.

(work around idea): If there were a way to change parameter #99 from within the G-Code program then I could command parameter #99 to an axis specific value before every new axis G1 movement?

MY SETUP:
All other parameters are default.  Changed parameters are:
#34=435.031
#35=394.242
#36=7875.575
#392=0
#41=6350
#42=1000
#43=250
#45=150
#46=7.5
#47=2.0
#100=6350
#101=1000
#102=250
#263=150
#264=7.5
#265=2.0
#15=0
#76=6350
#77=6350
#78=250
#79=250
#80=6350  (because each axis speed capability is unique I don't use G0)
#99=2.0  (works perfect for Z-Axis but acceleration too slow for X and Y)
#98=3797
#221=3625
#433=0
#448=1
#1=0
#115=1

(TEST CODE, SPEEDS IN mm/min, Locations in INCH)
G20
G90
G54
G01 F250. Z0.1
G01 F250. Z0.0
G01 F6350. X5.0
G01 F6350. X0.0
G01 F1000. Y0.5
G01 F1000. Y0.0

ytliu · Posted at 2018-10-4 16:39:53

math_indy Posted at 2018-10-3 22:33
On this surface grinder installation the DDCSV2.1 works great in CONT and MPG but inability to have ...

I optimized the program according to the parameters you provided.
Note: Set parameter #99 with the minimum acceleration in the XYZ axis.

math_indy · Posted at 2018-10-5 22:59:51

OH WOW--MUCH BETTER!

I installed custom version 2018-10-04-XXX and now I have the accelerations that I need on X,Y, and Z axis--VERY HAPPY NOW.

DDCSV2.1 is a fabulous controller!

Is it possible to tell me which file you changed and where? I am happy with this solution but I worry that, in the future, I won't be able to install new software revisions as they may not have the customized X,Y,and Z operation accelerations that this special version 2018-10-04-XXX has.

ytliu · Posted at 2018-10-6 10:44:43

Great video, thank you for sharing.

I upgraded the software because of a problem with the previous version of G2/G3 acceleration processing.

In the new version, #99 represents the combined linear acceleration. During the machining process, the actual acceleration value will be constrained by the manual start acceleration of each axis.
In addition, parameter #498 "J-parameter gradient" is added, which is used to describe the rate of change of acceleration. Since the rate of change of acceleration (J) must be less than 1/2 of the minimum acceleration value among the three axes, so 498>#99/(min(#45,#46,#47)/2).

For your application (#45=150 #46=7.5 #47=2), you can set it as follows:
#99=300;
#498=500;

Also, I noticed that your X-axis and Y-axis pulse equivalents are not the same, so set #113 to 1 (Soft algorithm).

math_indy · Posted at 2018-10-9 02:53:03

I installed 2018-10-06-XXX and changed parameters #99 and #498 as suggested (to 300&500). All axes work well under manual control but in automatic operation the Z-Axis acceleration appears to be messed up. X and Y accelerations seed to work as before and Z-Axis accelerates nicely from 0.000 to G01 F250.0 Z1.0" but upon reversal with subsequent G01 F250.0 Z0.0 the stepper wines and looses count. This Z-Axis malfunction did not happen with earlier install(2018-10-04-XXX).zip version which seemed to work nicely.

ytliu · Posted at 2018-10-9 17:55:57

math_indy Posted at 2018-10-9 02:53
I installed 2018-10-06-XXX and changed parameters #99 and #498 as suggested (to 300&500). All axes ...

Please download the latest firmware and configure the following parameters:
#99=300
#2031=1

Parameter #498 has been removed from the parameter list

Seperate X,Y,Z,A operation accelerations?

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