Control horn trim spring weldment contacting bottom of seat

Discussion for builders, pilots, owners, and those interested in building or owning a Waiex.

Re: Control horn trim spring weldment contacting bottom of s

Postby LarryEWaiex121 » Mon Nov 30, 2015 7:13 pm

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
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Re: Control horn trim spring weldment contacting bottom of s

Postby saddler » Mon Nov 30, 2015 7:21 pm

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
Sean Saddler
Troy, OH
Waiex #165
First Flight 10/16/2015
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Re: Control horn trim spring weldment contacting bottom of s

Postby Ray Krause » Thu Dec 03, 2015 12:23 am

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.
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Re: Control horn trim spring weldment contacting bottom of s

Postby Rynoth » Thu Dec 03, 2015 5:06 pm

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.)

Image
Ryan Roth
N197RR - Waiex #197 (Turbo Aerovee Taildragger)
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Re: Control horn trim spring weldment contacting bottom of s

Postby Bryan Cotton » Thu Jan 19, 2017 11:51 pm

Does that tab serve as an aileron stop or can I just hack it off?
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Re: Control horn trim spring weldment contacting bottom of s

Postby Bryan Cotton » Sat Jan 21, 2017 9:43 pm

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 Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Re: Control horn trim spring weldment contacting bottom of s

Postby kevinh » Sun Jan 22, 2017 11:04 pm

Bryan Cotton wrote: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)
Taildragger Waiex in progress, tail done, wings done, about to mate wings to fuse,
then cowl, canopy, paint (photos): flush rivets, turbo aerovee, acro ailerons
(I built my RV7A and happily flew it for about 500 hrs)
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Re: Control horn trim spring weldment contacting bottom of s

Postby Bryan Cotton » Mon Jan 23, 2017 7:52 am

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

http://www.rynoth.com/wordpress/waiex/2 ... ator-trim/
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Re: Control horn trim spring weldment contacting bottom of s

Postby kevinh » Fri Jan 27, 2017 12:44 am

Thanks Bryan (and Ryan)
Taildragger Waiex in progress, tail done, wings done, about to mate wings to fuse,
then cowl, canopy, paint (photos): flush rivets, turbo aerovee, acro ailerons
(I built my RV7A and happily flew it for about 500 hrs)
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Re: Control horn trim spring weldment contacting bottom of s

Postby waiking59 » Sat Jan 28, 2017 1:25 pm

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.
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