4th axis tangent to path XY

hi all
I tried tangentkins. and seems to work, only that I have the button touch off inactive (gray)
you know it can be?
thanks
Mauro

billykid wrote:

hi all
I tried tangentkins. and seems to work, only that I have the button touch off inactive (gray)
you know it can be?

Sorry, no, I have no idea. I doubt it is related to the kinematics, I assume there is something about the machine state in Axis that means that touch-off isn't likely.

Do you need to switch to World Mode? (xyz positions, not 123 joints). There is a menu option, or use $

In Axis you can only touch off when E-Stop is out, Power is On and you are in World Mode. F1, F2, $ is the shortcut keys.

John

Many thanks Andy, John ! touch off work properly but axes in world mode are noisy, I think perhaps excessive gain.
in mode 0 1 2 3 the movement is fluid.
I will try the next version of tangentkins so that it can be enabled only when needed.
regards
mauro

tell me please , how to activate the tangentkins and in the mode "manual"?
To make it work in all modes without exception...

nkp wrote: tell me please , how to activate the tangentkins and in the mode "manual"?
To make it work in all modes without exception...

Unfortunately Tangentkins is something of an experiment that nearly worked, rather than a good solution to the issue.

If I was doing it now, I think that I would use the axis.0.joint-vel-cmd and axis.1.joint-vel-cmd pins to calculate the tangent direction, and probably use a custom HAL component to drive the rotary axis.
This custom HAL component might require a link to the feed over-ride pin to slow the motion on a reversal.

Has there been any further dev on tangential path follow or does anyone know of a cam program that will give the c axis output with xyza ?

mgenton85 wrote: Has there been any further dev on tangential path follow or does anyone know of a cam program that will give the c axis output with xyza ?

From a quick Google it seems that Gcodetools (a plug-in for Inkscape) can do this.

An alternative would be an input filter for LinuxCNC. This would take normal XY G-code and add additional C-axis moves.

andypugh wrote:

mgenton85 wrote: Has there been any further dev on tangential path follow or does anyone know of a cam program that will give the c axis output with xyza ?

From a quick Google it seems that Gcodetools (a plug-in for Inkscape) can do this.

An alternative would be an input filter for LinuxCNC. This would take normal XY G-code and add additional C-axis moves.

yeah that makes no sense to me i tried to use the tangentkins with 2.6.4 but all that happens is joint 3 following error and i dont really understand the language yet
if tangentkins worked that would be ideal can you provide a helpful link so i can decode and learn your program? because i really need to have this capability and i refuse to go back to mach mach 60 ipm with steppers linux 200 ipm same setup except for encoders yeah not going backwards

mgenton85 wrote: can you provide a helpful link so i can decode and learn your program?

Can you re-phrase the question? I am not sure what you mean.