Engine thrust line

[funflyingguy]

hi kai,

jim (funflyingguy) here. i am considering a small rudder trim tab for my legacy sonex with the aerovee. do you happen to have any pictures of what you have on yours?

thanks jim

[Kai]

hi kai,

jim (funflyingguy) here. i am considering a small rudder trim tab for my legacy sonex with the aerovee. do you happen to have any pictures of what you have on yours?

thanks jim

No, but I´ll get you one.

Basically it is a flat sheet of .025 with the same dimensions as you find in the drawings for the elevator tab. When you see it bear in mind that the VW and the EP turn in opposite directions.

Rgds
K

[funflyingguy]

thanks kai,
i'm interested in which side of the rudder you mounted it to, how high/low you ended up mounting it, and which turn tendency you are correcting.
appreciate it....... jim

[Bryan Cotton]

thanks kai,
i'm interested in which side of the rudder you mounted it to, how high/low you ended up mounting it, and which turn tendency you are correcting.
appreciate it....... jim

For an Aerovee you typically need left rudder in cruise. This would mean you would mount it on the right side and bend it to the right, like on ours:


My trim tab came in the kit and should be in the plans, if you got those with the airplane. You can buy a trim tab from Sonex.
https://www.sonexaircraft.com/eshop/car ... ing=rudder

Here is one from sonex892:


I put mine on with aluminum rivets. Took two tries to get the bend right, and I drilled out the rivets to make it easier to bend.

[funflyingguy]

hey bryan...... thanks.

i do indeed have some need for left rudder in cruise. i cut a rudder tab from aluminum scrap based upon other readings here, and it turned out nearly identical to that in your picture. so right side of the rudder, bent right as needed. right now i will use 2-sided adhesive 3M tape. final install will be with rivets as well.

much appreciated bryan and kai.......... jim

[Skippydiesel]

I fly Rotax - right boot on TO.

I have a very small fixed rudder trim - only effective in cruise - to correct a slight tendency to yaw to the left. Ball now centred.

The tab is a short piece of aluminium curved profile (hardware shop), attached using double sided tape. I started with a selection of diffrent lengths. Ended with the shortest effective (even changed it a little)

I suppose I could rivet it in place, now that the location & size/length have been established, through trial & error but the tape does a great job so I think I will leave well alone.

[funflyingguy]

skippydiesel....

appreciate the feedback. i'm glad i used the 2-sided tape to start. i am satisfied with the low rudder location, but the shape and width may be slightly too much. i've decided to order the sonex trim tab with the URL provided by bryan cotton as well and go forward with that.

other projects with my sonex are calling. here are a few:
. better gap closure and seal at the back of my canopy.
. totally external way to attach the main strut fairings without fuselage holes or wheel pants.
. diagnose/resolve engine consistent roughness between 1200 and 1400 rpm's.
. left brake slightly grabbing, pulsing with or without center pull brake applied. (brakes are new and 'broken in').
. add ADSB-out (i have no transponder, altitude encoder or position lights wiring).
. fully resolve engine stuttering/stalling when engine hot and taxiing.
. add oil access panel to right side cowling.

now that i have a fully enclosed hangar, i can address some of these.

great site here. i have picked up lots of valuable information by reading through it and various builders' logs.

jim / funflyingguy

[Bryan Cotton]

. diagnose/resolve engine consistent roughness between 1200 and 1400 rpm's.

jim / funflyingguy

One thing that can cause roughness in an AeroVee is mixture too rich. The trick at low power is the mixture control is not super effective because of the low flow. But if you can get it to run well by leaning, even if it quits after a second due to lack of fuel, that will help the diagnosis. So what to do? Either turn the needle leaner, or swap to a lower # needle.

You want it nice and lean at idle, and just barely too rich at WOT.

[funflyingguy]

pretty much the same as my prior cherokee with the lycoming. i will definitely give this a try to further pin down this issue.

thanks bryan.....

[Skippydiesel]

other projects with my sonex are calling. here are a few:

. better gap closure and seal at the back of my canopy.

I use a P profile, self adhesive, gap seal. Works very well. Take your time in placing it so that the canopy only just compresses it at the contact point.

. left brake slightly grabbing, pulsing with or without center pull brake applied. (brakes are new and 'broken in').

Sounds like a warped or misaligned disc. If drum brake could be a loose or misaligned shoe.