scurve trajectory planner

Joco wrote:

Adaptive feed and feed hold are core to how plasmac for plasma machines operates.   However it does not use the gcode on/off capabilities that I have seen.

feed-hold issued during a tapping cycle could be catastrophic as it just stops xyz motion and does nothing to spindle.   Feed-inhibit would be appropriate then as it alllows synch motion as used in tapping to complete.

Adaptive feed along with external offsets allows for some cool cut recovery operations on a plasma or probably any jet cutting machine (e.g. Laser or water jet)
 

I was under the impression that LCNC already disables feed-hold in the background during tapping or other spindle-synchronized movements.  I think activating feed-hold has no effect until the tool is back at the retract plane.  Which is why I didn't think adding feed-hold disable feature to the s-curve Tp was necessary.

But I could see a use for adaptive feed enable/disable during g-code.  Hope I didn't give the impression I didn't think it was useful.
 

Don’t make that assumption re feedhold. And tapping. The planner is taking things direct from the Hal pin. Not from the lcnc motmod module.

it needs to be explicitly tested. Unless someone has done so already and can confirm what the behaviour is. 

Thank you for your answer.
I now understand every parameter and tested a little.

One thing I don't like. A given gcode with G64 P0.1 (mm) with an 90 degree edge. The small line upwards is 0.1 mm right of the edge. Your scurve tp sets a radius of 0.1 mm and the default tp sets a radius so that the distance between the blended path and the original path is not greater then 0.1 mm. I always set with a P value the maximum allowed deviation of a given path. So now I am not really sure. Can I just calculate something? 

juliankoenig87 wrote:

Thank you for your answer.
I now understand every parameter and tested a little.

One thing I don't like. A given gcode with G64 P0.1 (mm) with an 90 degree edge. The small line upwards is 0.1 mm right of the edge. Your scurve tp sets a radius of 0.1 mm and the default tp sets a radius so that the distance between the blended path and the original path is not greater then 0.1 mm. I always set with a P value the maximum allowed deviation of a given path. So now I am not really sure. Can I just calculate something? 




 

Ah, that's not ideal. P needs to be a tolerance, definitely not a radius cause you end up up needing to pick a super tiny radius which entirely negated the point of G64.

Yes, the problem with using a fixed blend radius on all segment intersections would be that the path deviation depended on the angle at which the two segments intersect, which would be rather unfortunate (If that is indeed what it is doing). For angles larger than 60° the blend radius and thus the feed rate could actually be larger for a 0.1mm deviation while angles below 60° would require a smaller blend radius to stay within a maximum deviation of 0.1mm.

Ok. As long as I am aware of it I can handle with it and I will choose smaller values.

Right now I am trying to get a 4 axis Machine running. Right now the scurve tp is making a lot dump things.

Grotius, do you have a 4 axis sim machine running to play with?