backlash & feedback, is there a strain gauge cure?

They are...

But in coordinated motion aren't we well, coordinating these two independent vectors into one motion? Just hitting the end point of a motion path at the right end time (i.e. area under the graph is correct) is not good enough, it has to be within an acceptable error at all points in time...

Backlash means something that should have an acceleration is undertaking zero velocity change so the other coordinated axis will have to account for that or you'll end up a zigzag in the coordinated motion path. Its either a zigzag or the other axis has to also stop and wait for the other axis to roll through its slop until they can run again, which begs the question of how to maintain constant feedrates.

I'm not saying there isn't a solution, I'm just wondering how its done - the control side of it more than the mechanical that is.

hmmmm,

ok cuter forces - something for me to ponder - but why isn't coordinated motion a problem ? off topic or actually not a real problem ?

I'm talking about coordinated motion between two axes - like a circle ...

The velocity profile (and accel and position) of a circle plotted in two orthagonal dimensions is two sine waves out of phase with each other by 90deg

If there is any lag or stopping in one wave (axis) the other must compensate 'immediately' (or within acceptable limits) so as to keep the resultant profile of the two axes combined (i.e. the circle) on path

While one axis hits the time it needs to change direction - i.e. backlash - the other one at its fastest velocity ... but to maintain the circle profile it needs to stop and wait for the other backlashing axis to catch up

max velocity does not equate to zero velocity - a contradiction in requests to the axis


I'm starting to repeat myself - hinting to me that one or both of us is either wrong, or not understanding the other (I'll note that although most cry the opposite that the internet is hardly a ideal place for communication )

I'm using argument as a method of understanding/learning - something I've learned my personality type does often - hope no offence taken :

I'll certainly look into the cutter forces complication, its something I'd like to get my head around. Got any reading online you could link to ?