## Discontinuity of A/B/C axis movement. document.SUBSCRIPTION_OPTIONS = { "thing": "topic", "subscribed": false, "url": "subscribe", "icon": { "css": "fa fa-envelope-o" } };

jonasz
2023-04-16
2024-05-09
• jonasz - 2023-04-16

Good day ,
I was given the task of making a 6-axis CNC machine (X/Y/Z/A/B/C).
The machine is a coil winder, where the A/B/C axes are the axes that rotate the spindles, and the Z axis is the axis that moves the wire from one extreme position of the coil to the other.
The problem is the discontinuity of A/B/C axis movement (velocity profile).
In the path preprocessing step, I am not able to get continuous ABC axis movement.
Here is the test G-code:

N000 G91
N010 G01 Z10 A360 F100 E1000 E-1000 FA100 EA10000 EA-100000
N020 G01 Z-10 A360
N030 G01 Z10 A360
N040 G01 Z-10 A360
N050 G01 Z10 A360
N060 G01 Z-10 A360
N070 G90

G-Code using the X-axis:

N000 G91
N010 G01 Z10 X360 F100 E1000 E-1000
N020 G01 Z-10 X360
N030 G01 Z10 X360
N040 G01 Z-10 X360
N050 G01 Z10 X360
N060 G01 Z-10 X360
N070 G90

In the attachments I present the movement of the Z/X/A axis.
X-axis motion is what I need.
This is how the movement of the A axis should look like. Unfortunately, it looks like in the attachment to the A axis.
Is there any way to "force" the ABC axes to behave like XYZ axes?

• gseidel - 2024-04-30

Hi jonasz,

you already solved it, I'm answering here for the sake of others with a similar question.

You can provide the slope of the A/B/C axis with the U/V/W word.

If you don't want to change the G-Code, the function block SMC_RecomputeABCSlopes can compute the slopes automatically.

Best regards,

Georg

π
1
• jonasz - 2023-04-25

Good morning,
I solved the problem. I was hoping for support, unfortunately.

• k2saki - 2024-04-29

Hello. Good morning.

I have a same problem with short-segment G01 in GCode even in XY Axis.

( I'm using SMC_ReadNcFile2, SMC_NcInterpreter, SMC_CheckVelocities before IPO , watching Youtube tutorial video.. )

How did you solve this problem ?

• jonasz - 2024-05-09

Hi,
My problem was related to the behavior of the modulo axis, but maybe you will find something useful from what I write.
The solution lies in path processing.
Codesys offers a G-code analysis tool.
Insert a CNC object into the project. The CNC settings object will be added automatically.
By inserting appropriate processing modules into the CNC settings object and parameterizing them, you can test the behavior of the axis.
When the effect is satisfactory, remember to add the module from CNC settings in the correct order in the processing path.
Each CNC machine case is different.
You need to spend some time to get your design tailored like an Armani suit.
Good luck.

• jonasz - 2024-05-09

PrtScr