Reverse Collective?

Is there currently any way to configure a Trex 700 or 800 to work with counter-clockwise rotating blades? The reason why I’m asking is the blades I’d like to test are asymmetrical and only available in a counter-clockwise rotation. Its easy enough to flip over the one-way bearing and reverse the motor, but I’m running a 3-blade rotor head and I cannot flip the blade grips over to work in the opposite direction, so then the only way it would work is if I can make everything work with reverse-collective, but not sure that’s possible the way the current arming & failsafes are configured.

I figured out a solution, just need to add DFC grips and ditch the control links so I can eliminate the control arm, then I can flip all the grips over, no need to reverse collective.

Hi! Could you share the details of how are you going to perform this test and obviously the results of it? It intrigues me a lot to know how much difference can the asymmetric blades make.

Yes I can, but I won’t have a set of symmetrical blades of the same length for comparison. Also, flight time is highly dependent upon rotor head speed, asymmetrical blades allow you to generate similar lift at lower head speeds. Additionally, the minimum head speed you need is dependent upon flight speed and payload, so there are a lot of variables in play here.

If you are using Copter 3.6, there has been a new parameter added that allows you to reverse the collective direction. it is called H_COL_CTRL_DIR. Sorry that I didn’t respond sooner.

As Bill noted, in 3.6 you can reverse the collective direction to have either leading or trailing edge control for reversed heads. I actually wrote that code for ArduHeli 3.5.x, and it was never in Copter 3.5, but it is now in the Copter 3.6-rc’s.

Ok thanks that’s good to know, I’m still running 3.5 so didn’t have that parameter, but I managed to flip the grips over, and get everything else switched, just waiting on a few parts, then it should work. If I run into any issues, nice to know I can upgrade to 3.6 and run all the mechanics normally.