F7a differential aileron

9 posts in this topic

Posted

Hello everyone. I just put the upgrade F7a differential aileron parts in my mixer of my Avid mark IV and set the rigging as per the builders manual. Everything seemed alright until I got up to join the circuit and found out I had very little response with right aileron. All I could do to keep it level and don't dare drop the left wing. Had to make some very peculiar turns stabbing the rudder to the right and managed to get her back on terra firma. I must say I impressed myself by staying out of the bushes. Has anyone had any problems associated with the differential aileron upgrade. Thanks.

Share this post


Link to post
Share on other sites

Posted

Hello everyone. I just put the upgrade F7a differential aileron parts in my mixer of my Avid mark IV and set the rigging as per the builders manual. Everything seemed alright until I got up to join the circuit and found out I had very little response with right aileron. All I could do to keep it level and don't dare drop the left wing. Had to make some very peculiar turns stabbing the rudder to the right and managed to get her back on terra firma. I must say I impressed myself by staying out of the bushes. Has anyone had any problems associated with the differential aileron upgrade. Thanks.

I did the upgrade with no issues as have many others. Go back and check your rigging. Did you put one of the arms on backwards by chance?

Share this post


Link to post
Share on other sites

Posted

Thanks for the response. I got thinking it over again and wonder if to much fuel in the left wing (plane had been parked for a couple hours on a slight slope) combined with torque effect of the prop and my weight on the left side all add up to no response. How critical is the side to side balance. Both tanks run down to the header tank but there are no valves to isolate the tanks. Fuel can run from one tank to the other. The plane is a standard mark IV STOL with subaru and 70 inch warp drive. It's on airdale wide gear with skis right now. Cheers. B

Share this post


Link to post
Share on other sites

Posted

I don't think it's very critical. A lot of Avids out there only have a tank in the right wing.

Share this post


Link to post
Share on other sites

Posted

Be sure to check your rigging on the ground to be sure the flaperons have nearly equal travel up and down with full deflection of the stick side to side and equally ballanced when the stick is centered . You can fly the avid with one tank full no problem.

Share this post


Link to post
Share on other sites

Posted

Thanks for the response gentlemen. I will recheck all the rigging for sure! The way I understand the manual it says to level the wings and then set the flaperons to -3degrees. Pretty sure I did it that way but you never know. -3 would mean the flaperon is slightly up when stick is centered? The movement is definitely not even traveling up and down. Thats it for now till I can check it all out. Cheers. B

Share this post


Link to post
Share on other sites

Posted

Thanks for the response gentlemen. I will recheck all the rigging for sure! The way I understand the manual it says to level the wings and then set the flaperons to -3degrees. Pretty sure I did it that way but you never know. -3 would mean the flaperon is slightly up when stick is centered? The movement is definitely not even traveling up and down. Thats it for now till I can check it all out. Cheers. B

You can set them to -6*degrees, see attached.

post-53-13291535799827_thumb.jpg

Share this post


Link to post
Share on other sites

Posted

Checked it all out again today. Had the adjuster rods with the tie rod ends in upside down. Didn't have an illustration when I first put them in. Leveled the wing and reset the ailerons to -6 degrees. Also am shortening limiter cable at back of the skis. They were a little long and probably were a big part of the problem. Went through every bolt and did discover a couple of jam nuts loose. One was even in backwards. Flat side is the jam side. The tie rod end by the universal at the bellcrank on the floorboard was twisting in the threads rather than the universal doing its job. It's all snugged up now. Just have to test fly it now! Thanks again.

Share this post


Link to post
Share on other sites

Posted

-6 made my roll really stiff. I ended up with about 4-5. When I want to yank and bank I just pull up a little tiny bit on the flap lever to relieve the pressure off the roll. When I do that though it's out of trim and wants to fly nose down.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now