the gkid bought over one of those gyroscope toys and i stole it for awhile last night and made some interesting discoveries about stability and the cp's hiller flybar/paddles and gyroscopic stability

when you spin up the gyroscope, it will sit on a string or even on the point of a leaning pencil without falling over - the heli should be doing the same but as it falls over, the flybar is supposed to stay level like the gyroscope and correct the heli back upright, but it wasn''t - the flybar was falling over too - why?

to make a long story and a lot of research short, in the tradeoff between performance / response latency time and stability, stability lost - the flybar paddles are too light to be a good gyroscope and supply the heli with a stable horizontal mass to measure and correct deviations out of plane - if the flybar paddles were made of a heavy metal like lead, they would produce the desired horizontal gyroscopic mass but would probably burn out the motor with all that weight, not to mention the tiny servos that have to push them around

but the servos don't actually push the flybar up and down, they only impart a twist, so the paddles do the heavy lifting - as long as we keep aerodynamics on our side, we can go higher on the paddle weight until we see resistance from the motor

so i increased the paddle weight by half again as much - good results - stability increased - went up some more until motor drain increased, so i had to back down again - ended up with an approximate 60% increase in paddle weight - 3 grams becomes more like 5 grams, but maintaining aerodynamics perfectly

i remembered we used to add collar weights to the flybar near the paddles, but this is in the axis of rotation and only helps some, and it is too far in, the weight needs to be at the ends of the paddles - the collars don't address the real issue of inherent gyroscopic stability, which is aerodynamic as well as gyroscopic

by increasing the flybar paddle weight 60%, while still maintaining the aerodynamic shape of the paddles, i achieved what could only be described as a balance point - stablity without loss of resolution or an increase in latency (the time from control input to execution)

bigger or further out hiller paddles are not the answer, neither is any other method except increasing the flybar weight across the outermost portion of the flybar paddle

i tried a bunch of methods for increasing the weight in the exact right place, from rubber grommets as dampers on the flybar, to black electrical tape on the paddles, to lead fishing weights sticky taped to the ends, but the paddle's aerodynamics must be maintained or resolution will decrease and latency will increase - the absolute best would be some outer portion of the flybar paddle being metal, like the last 1/4 inch being metal or something heavier than the current plastic

so far the best plastic paddle mod is to drill a hole in the plastic paddle perpendicular to the rotational axis and as far out toward the tip as possible (while remaining in the area of viable thickness), filling the hole with flybar-sized music wire, then grinding the exposed portions of the wire to make it flush with the plastic aerodynamic surfaces

i hereby call this stabilizing method the 'flybar paddle gyroscopic stability mod', or just 'gyroscopic stability mod' for short, or 'paddle mod' for even shorter


edge


edit: someone may have gone here before - i don't know - if such a thing as a metal-tipped or weighted flybar paddle already exists then let me know asap please