4th axis tangent to path XY

Using A value in gcode would be a place to start.
What needs added to kins?

Thank you for your help.
~*Brian

Hi,
only today i was able to test the new tangentkins.c, all is ok.

The file work fine with m-codes. I can lock A axis on tangent path or unlock and use it in a standard way.

Many thanks.

Hello,

i've tried your tangentkins with the default config for Sherline4Axis, because it's config is very similar to my machine.
I replaced trivkins with tangentkins.

My problem is that i alway get the following error:
37403: ERROR: joint 3 following error

Am I doing something wrong?

Hi,

thanks for your reply.
We've decided to use another software for that, but it's not as cool as EMC.
So I am still interested in cutting with EMC.

However I've tried to "short-cicuit" the position feedback this way:

net apos-cmd axis.3.motor-pos-cmd => stepgen.3.position-cmd
net apos-cmd => axis.3.motor-pos-fb

I simply set axis.3.motor-pos-fb to the input of axis.3.motor-pos-cmd.
This did not work, i got FOLLOWING ERRORS for all other axes. So i tried to do this for all other axes as well.
This worked ok, but now i get a new error:
Exceeded soft limit

This error appears, when axis position is out of range.

Have you any better idea, how to do that?

and almost nobody needs it.

I don't think so. Even Mach3 has a tangential controller.
And it couldn't be that hard to implement.

Thanks

Hi all,

I installed a 4th axis to make cuts with tangent knife (using a circular blade) and got very good results with Gcodetools. Nick, the principal developer, is very friendly and helpful. In the last stable version (1.7) you have to change the 4th axis scale from 1 to 180/pi to have it generate the angles in degrees. I already tested it and works very well.

If you need, I can elaborate better how I did it.

Regards,

Dimitrios

Hello Dimitrios,

thanks for your reply. Do you mean the inkscape extension gcodetools?
Sorry but this is no option for me. I want to be independent of any CAM software.

When I've time I'll try to write a preprocessor for that, this is probably the best solution.

Hi Molotow,

I understand what you want, I thought about doing it too, but my programming skills fall short for this task

I am still learning to use inkscape, but the more I use, more I like it, and the Gcodetools interface is very simple, once you go through the learning curve. for now and for me, it is a good fit in the workflow.

I'd rather use inkscape and gcodetools to load it to LinuxCNC than using any other controller.

I will try to use the tangentkins soon, keep us informed of your progress.

Regards,

Dimitrios