wrap y to a axis

Hello,
I am trying to engrave a cylinder. My idea was to program in X and Y and the machine convert the Y CAD data into angular position and rotate the axis.
I wrote a custom comp that also works in the halshow. A simple test was to move the Y axis 3.14mm with a diameter of 2mm and then rotate A 180 degrees.
ytoa.0.ypos is the input and ytoa.0.a is the angle converted.
With M100 / M101 it should be switched on and off.
A few questions remain unanswered and perhaps someone can help.
1. How can I forward the angle from ytoa.0.a to joint.3.motor-pos-cmd to avoid the following error?
2. My vismach is still bent. The A axis should rotate around itself and not in circle?
3. How can I clamp a workpiece there that will be engraved?
I attached my working folder.
Thank you...

Regarding the vismach model: Try changing this:

# A-axis move to X, Y, Z centerpoint
atable = Translate([atable],600,200,-200)

atable = HalRotate([atable],c,"ja",1,0,0,1)

To this (ie add the rotation before the translation):

atable = HalRotate([atable],c,"ja",1,0,0,1)
# A-axis move to X, Y, Z centerpoint
atable = Translate([atable],600,200,-200)

I cannot test your config right now as I am away from my test setup.

Regarding following error:
Linking and unlinking 'ytoa.0.ypos' is likely to create a discontinuous signal for motor command which in turn creates a following error. To avoid that you may want to pass 'ytoa.0.ypos' through a 'limit3' component:
linuxcnc.org/docs/html/man/man9/limit3.9.html
Alternatively you could write a custom kinematic component to switch between trivial and wrapped kinematics.

Regarding the work piece:
Do you mean simulating the work piece in the vismach model? You can create a Cylinder in vismach that will dynamically change it's diameter with the 'diam' value of your component. Have a look how the tool cylinder is created in the other vismach models.

 Yes. One point less. 
correct line is 
atable = HalRotate([atable],c,"ja",1,1,0,0)
# A-axis move to X, Y, Z centerpoint
atable = Translate([atable],600,200,-200)


 

An alternative is to do the conversion in the g-code post processor.

Hakan wrote:

An alternative is to do the conversion in the g-code post processor.

 I did it last years. But the target should be one parameter program including scaling.

An alternative is to do the conversion in the g-code post processor.

Yes or as another alternative use a python filter script that changes the XYZ to XAZ code.
 

Aciera wrote:

Regarding following error:
Linking and unlinking 'ytoa.0.ypos' is likely to create a discontinuous signal for motor command which in turn creates a following error. To avoid that you may want to pass 'ytoa.0.ypos' through a 'limit3' component:
linuxcnc.org/docs/html/man/man9/limit3.9.html
 

I try 
halcmd unlinkp joint.3.motor-pos-cmd
halcmd net J3:pos-cmd ytoa.0.a J3_pid.command
but after 0,3mm i got position error. I guess the limit3 will not help
 

Alternatively you could write a custom kinematic component to switch between trivial and wrapped kinematics.
 

I try it but this is behind my mind.

 

Regarding the work piece:
Do you mean simulating the work piece in the vismach model? You can create a Cylinder in vismach that will dynamically change it's diameter with the 'diam' value of your component. Have a look how the tool cylinder is created in the other vismach models.
 

Yes. if the diameter for "setp ytoa.0.diam 2" change should be the workpiece diam in vismach change too.

Good idea 

I think it is cool if you can make this work. I'll keep watching.

I try 
halcmd unlinkp joint.3.motor-pos-cmd
halcmd net J3:pos-cmd ytoa.0.a J3_pid.command
but after 0,3mm i got position error. I guess the limit3 will not help

I'm not sure partially because I'm really not very clear on how the position command and feedback is handled in a sim config but I feel that using a custom kinematic component would make things a lot simpler since you don't need to link and unlink command signals and the a-axis motion would still be handled in the motion planner. It probably can be done in a hal component but to me it seems somehow like reinventing the wheel.

Anyway the attached config contains a modified vismach model with dynamic work piece diameter which you may find useful.