If you want my “2 cents”, it certainly sounds like it could be useful functionality. Some random comments:
- A challenge is likely going to be getting hardware widely available. It’s a bit of a “chicken and egg” situation - it’s hard to write the software without known hardware to work on, but hardware manufacturers are unlikely to widely manufacture devices without software support..
- If one did want to set something like this up, I’d recommend hardware with at least 10mm or so of “buffer” between the two motors. You likely don’t want the two motors directly attached to a rigid ptfe tube where they could be “fighting” each other.
- For what it is worth, if you’re planning on an implementation that tries to quickly react to “force measurements” then I’d guess that would be challenging to implement in Klipper. Everything in Klipper is designed to be scheduled well in advance. As an alternative to direct responsiveness, one could look to schedule filament movement on both motors and use the “force sensor” to constantly alter the ratio of motor movement for the two motors. Said another way, instead of trying to react to measurements, try to predict the measurements in advance so that motor movements can be scheduled.
Again, just some random thoughts,
-Kevin