Control horn trim spring weldment contacting bottom of seat

[LarryEWaiex121]

Ryan,

Quick word about the trim spring and how its going to effect the whole flight envelope.
The Waiex really doesn't need a tremendous amount of up trim. Unfortunately, the only time you need "lots" of up trim is in full flap landing configuration. You will just end up doing it the Armstrong method.
In your normal flight regimes you will probably use very little up trim and substantially fly the entire flight, dialing in down trim as your fuel burns off.
In my Waiex, I went in and changed the spring to afford me more down adjustment. Deliberately. I stretched the spring a couple inches more than the instructions indicate on the pushrod. I don't mind a plane I have to hold a bit of up elevator for awhile but, hate a plane that you have to constantly hold down elevator in level flight. This mostly occurs at full up seat weight and minimal fuel load.
In my Waiex, I have the Jab 3300 and I have my gross set at 1200lbs. No, I don't want to start another discussion on what should be. It is what it is. With 440lbs in the seat, I run out of down trim at about 6 gallon mark. From then on its forward stick till landing time.
If you ever fly at such weights you will learn the value of smoothness on the pitch inputs.
As a side note, there has never been a plane I've flown that was as neutral on the controls as a Waiex "in landing configuration". Even in the middle of the CG envelope it requires very minimal pitch inputs to flare. At aft CG conditions you essentially fly it into ground effect and hold it steady. No flare whatsoever and it will 3 pt. on its own.
Sorry for the wandering off subject, but the trim is mostly needed for nose down.

Larry
Waiex121YX

[saddler]

I talked to Kerry about this and initially bent the tab up slightly but that made the rub on the seat pan worse. That is when I decided to adjust the seat mounting hinge location to take some of the slack out of the seat pan. When it came time to rig the flight controls I tried as hard as I could to get full throw but what I found out was the aileron counter weights would hit the wing skin before the controls would hit the mechanical stops on the yoke assembly. I got within a degree of the recommended throws in the plans but ended up adding some rubber tubing over the mechanical aileron stops on the yoke assembly so that the controls were hitting a mechanical stop so as to not allow the aileron counter weights to hit the wing skin and end up putting the aileron pushrods in a bind. I have the aerobatic ailerons and I think you will be find they have plenty of authority :D

[Ray Krause]

My solution after trying all the above suggestions was to use a much shorter and considerably stronger spring connected to the weldment with a short cable! The other end of the spring connects to the trim cable as usual. The cable from the weldment :!: to the spring goes under the pan nicely and the spring stays well below the seat pan. My spring is a little too strong, so trim adjustments only require a slight movement of the knob. 1/8 turn is the most I usually need; 1/2 turn is pretty much the most I use for landings and take-off.

[Rynoth]

I notice on the control horn assembly that there is an additional welded tab on the right side, beneath the aileron crossbar. What if I attached the trim spring to this point? The spring would be pulling at a diagonal from a lower point on the frame (meaning less effective pitching moment from the spring), which might not be a bad thing at all (since there's been some mention that the spring tension is generally more than what's needed in the Waiex.) I checked clearance and it seems like it would work. I could then remove the triangle tab that's causing me problems, both giving me full aileron authority and no longer scraping on my seat pan. Thoughts?

In this pic i've circled the location of the tab I'm referring to (it's a bit out of focus.)

[Bryan Cotton]

Does that tab serve as an aileron stop or can I just hack it off?

[Bryan Cotton]

I realized this tab was not a stop. This was its death sentence.
https://youtu.be/-p55BM25Guo

Adam was safetying the mixer mount bolts.

[kevinh]

I realized this tab was not a stop. This was its death sentence.
https://youtu.be/-p55BM25Guo

Adam was safetying the mixer mount bolts.

Bryan - without that tab, where are you attaching the trim spring? (I'm not yet at this point but soonish)

[Bryan Cotton]

Kevin,
I'll probably do something similar to Ryan.

http://www.rynoth.com/wordpress/waiex/2 ... ator-trim/

[kevinh]

Thanks Bryan (and Ryan)

[waiking59]

Has anyone found an alternative method to attach the trim spring to the controls that works?[/quote]

Kerry told me not to change the location of the spring mount. My solution was to rivet a piece of .062 6061T6 sheet on top of the seat pan over the contact area extending from the stick openings side to side and from the bend aft of the spar tunnel to the lower bend. I used AL rivets, no contact issues now.