4 axis tangential knife

[abd97khateeb]

Hi, When i start the 4D A tangential machine, A axis rotates correctly in linear shapes, but in curved shapes it rotates differently than the simulation. What is the reason for this?
video:
https://drive.google.com/file/d/1kFYyj0nKejBGwWmeREaVROWiceNVjwZd/view?usp=drive_link
Kopy video:
https://drive.google.com/file/d/1kFYyj0nKejBGwWmeREaVROWiceNVjwZd/view?usp=drivesdk

[svenhb]

I asked for access to see the video...

[abd97khateeb]

İ accept

[svenhb]

Ok, my first thoughts:

• there is no feedrate given in the gcode - that is propbably the problem for the simulator.
  Will try to fix that.
• you didn't define a pen up/down-translation (no code before "(PD)"): https://grbl-plotter.de/index.php?id=form-setup-3#pen-up-down
• it is just a simulation, better check on real system
• Why the marked tabs are highlighted?
  

[svenhb]

you didn't define a pen up/down-translation (no code before "(PD)"

perhaps it is a bug, did you enable "Process meta data for SVG graphic?

[abd97khateeb]

When the code is like this: G02 x10 y10 I0 J10 A90, it executes the xy section first, then A. I think the problem is in the code generation because it gave the same problem in another simulation program.

[abd97khateeb]

Is there another way to write code that contains a circular shape?

[svenhb]

When the code is like this: G02 x10 y10 I0 J10 A90, it executes the xy section first, then A.

If the command is in one line, X,Y and A will move at the same time

Is there another way to write code that contains a circular shape?

E.g. Import circle from SVG (Inkscape) and enable this

[svenhb]

If I use your settings, my code looks like this - with Z axis:

When you experimenting with settings, you should disable "code add on" - the "old" code stays on top....

[abd97khateeb]

Ok thanks i well try.

[abd97khateeb]

can I convert Z axis to A axis when creating the code because i used Z axis for tangential knife ?

[svenhb]

If you use Z axis for tangential, you may use a servo (controlled via PWM) to lift the knife. Then you need to select this options:

Also note: https://grbl-plotter.de/index.php?id=tangential-knife-1
Units per turn: if using 'Z' as tangential axis, the feedrates will slow down the rotation speed. Using just e.g. 36 units per turn may increase the performance. - Then you need also to adapt setting $102: https://github.com/gnea/grbl/wiki/Grbl-v1.1-Configuration#100-101-and-102--xyz-stepsmm

https://grbl-plotter.de/index.php?id=tangential-knife&setlang=en
Calculation of $102 (instead of step/mm I use step/1°), If the knife is connected directly to the Z stepper motor: One revolution = usually 200 steps - times microstep (m = 2, 4, 8, 16 or 32)
$102 = 200 * m / 360° = 0.555 * m. For “units per revolution” use “360”. This can lead to poor performance due to low acceleration rates. To get around this:
$102 = 200 * m / 3.6° = 55.5 * m. For “units per revolution” use “3.6”.

[abd97khateeb]

ok i will try this options, thanks.

[abd97khateeb]

How can I modify the drawing to combine with the black drawing?
![image](https://github.com/svenhb/GRBL-Plotter/assets/169066818/29e1aff5-add8-4cdd-ba4d-7ef3c672cdeb

[svenhb]

What do you mean with "combine"? For SVG graphic changes I would use Inkscape...

[abd97khateeb]

My gcode is difrent than svg shape.

[svenhb]

I assume you enabled some additional options, please check code and GUI:

[abd97khateeb]

thanke you for helping