A great idea to find a solution to a very real problem.
A few concerns and possible solutions on your idea at [groups.google.com]
1."Does the extruder go up as the platform rises? if so, how?"
2."at the right settings/size of moves, a strong resonance will develop that will have the extrude slamming into the arms."
Possible solutions
1." to just suspend it from one point at the top middle and just use a counterbalance weight."
"possible to add a secondary positioning spring that only engages when the head falls too far out of position. Designed right, the combination should be able to be made to work such that it does not have any sensitive resonant modes, and yet, because it is a spring, nor does it violently affect movements in the end effector."
A few concerns and possible solutions on your idea at [groups.google.com]
1."Does the extruder go up as the platform rises? if so, how?"
2."at the right settings/size of moves, a strong resonance will develop that will have the extrude slamming into the arms."
Possible solutions
1." to just suspend it from one point at the top middle and just use a counterbalance weight."
"possible to add a secondary positioning spring that only engages when the head falls too far out of position. Designed right, the combination should be able to be made to work such that it does not have any sensitive resonant modes, and yet, because it is a spring, nor does it violently affect movements in the end effector."