Tim Meakin 1

Thanks for that Ray. I will go to the Midlands show in October !! Yes, I really enjoy the hobby with all its different interests. Something for everyone. Cheers Tim

I went on Friday, for the first time ever, as I have worked abroad most of my life. I have retired recently. The show was fine and I am glad I went, but left feeling uninspired. It was pretty empty. I build and fly planes and helicopters (electric and IC). I have a Mill and Lathe and am toying with the idea of making an RC engine. So this show looked like right up my alley. I saw only two small Radial engines. There wasn't much on the planes or machinery fronts. There is a thread on our sister Forum by Paul Kemp that sums it all up very well. **LINK**

Thanks for the welcome. This is a nice Forum. Yes, you have got it exactly right. The FBL only knows how much servo rotation it is requesting. I doesn't know, on your particular heli, how far out the link is on the servo horn, what is the diameter of the swash input (bottom), or swash output (top), or length of main grip arms, etc. So you go to 8 degrees measured, and tell the FBL this is it. Now it knows the mechanical gain and how much servo travel provides how much change in pitch at the main blade. They use 6 or 8 or other very similar number because that is close to typical maximum cyclic pitch. Cheers Tim

Posted by Biggles' Elder Brother - Moderator on 24/03/2018 12:07:16: Q1: I've just noticed something else about this setting the cyclic to 8 degrees thing. In adjusting to close to what it expects the position to be it moves both blades in the same direction - ie they remain in one plane. Very odd. So that means if you measure one it will indeed be at negative incidence and you will get about -8. If you measure the other one it will have a positive incidence and measure +8! Go figure that! Q2: Then we do this set to 8 degrees thing for the cyclic - yer what? I've done it, I've done what it tells me to, but I don't understand what its doing. Why specifically 8 degrees? If it's cyclic why only in one position? A mystery - unless you know otherwise! A1: Think of Ailerons on a plane. Bank left, one side goes up the other side goes down. Collective = both up and down together (more or less lift). Cylcic = differential to get roll and fore / aft pitch. A2: Most FBL controllers need to be taught the sensitivity of the mechanical setup. By setting a fixed number of degrees (here 8, BeastX is 6), then confirming, the FBL knows how much servo rotation was needed to get that deflection. If the resolution is too coarse or too sensitive, you have to alter the mechanical gain in the horns / servo wheel / linkage. Then the FBL is calibrated to your specific mechanical setup. Hope that helps. Great build log. Cheers Tim