I did some not purely scientific but informative (to me) testing of various chemicals on Avid fiberglass tank pieces with various tank sealant materials painted in spots on the fiberglass. I put the pieces in Ball canning jars with whatever the chemical was. The sealants were buna “n”, proseal, epoxy resin, and some others. Av gas had no effect on the glass or any sealant. Ethanol free auto gas was good too. The worst was ethanol 10%. It softened the fiberglass and delaminated the buna n, swelled the proseal slightly and did not seem to affect the epoxy. Interestingly, pure ethanol (195 proof everclear) did not have near the bad effects of the 10% ethanol gas, although it did effect on the buna n and a very slight softening of the fiberglass. While the surface of the fiberglass was softened slightly it did not loose structural integrity over the two weeks, but from my experiment I will not use any fuel with ethanol in my tanks. i posted a lot more detail on another thread a long time ago on this site somewhere.
I am trying out a new (to me) Tygon LP1100 low permeability fuel tubing. It is clear but has a liner. The outer part seems to be urethane like regular UL fuel tubing, but the liner is supposed to be impervious to highly aromatic(sp) stuff in fuel and meets all the California rules for fuel line. Haven’t installed it yet, so don’t know how it will actually work in practice. But if it works like I hope it should have a much longer life and not get brittle and crack. I think I bought it from US plastics if anyone is interested in having a look.
Here are a couple of photos of my linkage. The linear motor under the passenger seat adjusts the flaps. Things may not look exactly like yours because the original builder of my plane did a lot of cutting and trimming of things I think he shouldn't have, but it is what it is. None of what he did affected location or basic geometry of any of the control system.
I got the flu and just got back from the dead. I guess I forgot that I took quite a few photos of the mixer assembly in my fat avid thread on this site. Let me know if you want any additional pictures. I should be able to get out of the house soon!
I do not believe MKIVs came with F7s. My MKIV was a late sn very much built to plan and it did not have them. I guess I didn’t know that any avids came with them. I thought it was a part you could buy as an extra if you did not want to use the rudder. I always believed that having full differential travel provided the greatest authority even though it required more rudder input to stay coordinated. I don’t think any of my avids have F7s from the pictures I have see on this site.
Absolutely! Every one of my Avids had the issues you describe above. Once full travel is obtained by fixing all the little builder induced issues the travel is what it is by design and won't vary from plane to plane.
It's only 40 degrees down on the "down" aileron. It will be approx 15 degrees up on the other one at full deflection. I got these numbers on every Avid I have owned My original MKIV got those numbers, My Magnum was identical, and my Fat Avid once all put together came up with exactly the same deflections. That's how I got the numbers. I seldom use a lot of flaps, but in a lot of Avid time, I have never experienced roll reversal, but I have heard of it happening. I also have no experience whatsoever with the F7 mod. Maybe that makes things move too far
Flapperons should travel plus and minus 25 degrees limited by the bottom of the stick hitting both sides the little triangle pouch it lives in. pulling full flaps should displace the flapperons an additional 15 degrees down and not cause any bind in the initial flapperon travel described above. So, with full flaps pulled and full aileron in one direction or another, max down deflection should be 40 degrees. THIS SHOULD ALL BE ABLE TO HAPPEN WITH WITH NO BINDING OR TRAVEL LIMITING EXCEPT AT THE BASE OF THE STICK which is the travel limiter. Hope that makes sense. :-)
So, interesting conversation about using all-thread above. So there I was yesterday at a friend's grass strip practicing slow short landings just above stall. I had just completed a landing, had turned around and was blasting off for another when the stick started moving around in my hand in a way that is hard to describe, but immediately disturbing. The strip is a bit rough so I thought maybe just that. It was getting worse as I accelerated so I aborted just before liftoff. I turned around and accelerated back to the starting point and it did it again. A very creepy and kind of violent but not really movement in the stick like something was broken. When stopped at the top again I moved the stick back and forth and it seemed firmly connected to the flapperons. When I moved it for and aft it felt like the elevator was firmly attached without excess slop. When I got out of the plane I found this: (photo) The strip is remote but I was able duct tape and bailing wire the trim tab in place to fly it home. The original builder used all thread for the connection and had a slight bend in it for clearance. I never thought a thing of it because I would never expect the forces to be great enough to bend or break the all thread. What I did not take into account was the infinite number of small flexes happening to that slightly bent piece of all thread led to catastrophic failure. I think it could have turned out to be a much bigger problem if it had failed mid flight. I think what happened is best described as a form of flutter. Lessons learned for me: 1) The control arm should have been straight, not the gradual bend the original builder had in it and 2) I I will probably use all thread for this again even though I am not a fan, but it will be straight and I will sleeve it.
I think that is the fuselage I have too. I love the room. Super fun to fly and well behaved. I think the control arrangement leaves a lot to be desired. While the mechanism under the seat and cables is convenient, Mine leaves a lot to be desired wrt flapperon slop.