Speed brake assembly
The speedbrake is actuated mechanically by a servo which is mounted on a removable ply platform just ahead of the speedbrake cutout.
As well as containing the servo, this assembly has the speedbrake hinges mounted to its sides, so that the whole servo and moving surface can easily be removed an inserted as a complete unit.
The photo below shows the speedbrake assembly before the door is attached. (The two long C/F pieces on the left will later be glued to the speedbrake door.)
The hinges for the speedbrake each consist of two carbon fiber plates with a washer between them, held together with a 2-56 button head screw. Note that for each hinge, both plates are tapped 2-56.
What this means is that when the speedbrake is lowered or raised we are effectively tightening one hinge and loosening the other. To account for this, without the possibility of binding, I ended up backing one hinge-screw (the stbd one, I believe?) out 1/4 turn. (I toyed momentarily with the idea of making the outer arms have clearance holes instead of being tapped, but was concerned that if I made this modification then the threads in the screw would wear the C/F part. A quick phone call to Dana at BVM confirmed that a clearance hole would indeed be a bad idea as it would lead to slop over time.)