Motion Tests Day 5

Actually ran this test series yesterday and analyzed the data today.  It is becoming more apparent that acceleration is a factor we need to take into account.  We also will need intensify adjustments based on how well the last adjustment responded (i.e. if we call for 300°/s² and get 150, we need to double whatever we did in the last frame).

It appears the transducers are more responsive than the 250ms latency I have seen published.  I am bumping up the master timer to 125ms to see if that fixes some of our weird occilations.

There may be an fundamental design problem with the actuator attachment points.  In the design I thought that since the center of rotation of the double-cardan main joint was 5 inches below the bottom sheathing that the centers of rotation of the pitch/roll actuators needed to also be at 5 inches.  What I am seeing now is pressure on the linear bearings (especially roll actuators) as they try to “straighten” with the now translated extended rotation point.

Is this the reason other 3DOF designs use 3 actuators instead of 4?  I thought it was to save coin and that the calculations for 4 actuators is actually easier since you have 2 dedicated to pitch and 2 dedicated to roll.

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