Control Stick Length

[Schmleff]

I had always blamed my planes pitch sensitivity on the airfoil shaped tail and the gap seals.

I am building a new control column to lower the seat.The control column was partially completed when I got the project but fit so I did not question it. Since there were a bunch things that were different than the plans I started measuring things trying to figure out why they were built differently. I did not want to build something that did not fit. Most of what was different looked like solutions to mistakes that would have caused clearance issues.

The plans call for the control stick to be 9.375" from the pivot point to the top. Mine measured just over 12". I can't blame that on the previous builder since I built the stick. What I did wrong was put a teak wood grip on it that increased its length by 3 inches. Duh. The mechanical advantage was increased from about 3 to about 3.82. No wonder it had almost no resistance to stick movements during landing.

The reworked stick will be adjustable from a 7-10 inches. It allows both tuning the stick force and removal of the upper part of the stick for maintenance.

 

[patmc]

when I first finished my control assembly, I sat in the seat and tried it on for size and comfort. I found that with the stick in neutral elevator position, my arm was extended too far forward. To make it more comfortable for me, I made an offset in the stick to move the top of the stick further aft. I just made sure I started the offset high enough so there was no limit to control travel due to stick and seat frame or cushion contact when full control inputs, both elevator and aileron, were applied...PatMc

 

[JoeB]

Mine is offset as well, with 12" from the pivot to the top of the stick.
Looking forward to reporting back with my findings once flying!

 

[Bil4381]

I've found that if the stick is too short it hits the pilots seat pan before full elevator travel. If it is too long it hits the back of the Passenger seat. The only way to be certain is to sit in the aircraft and operate the stick with someone checking for full travel. If you make the tube too long now, you can always trim it to length with a pipe cutter later. Bill E

 

[Schmleff]

Bill,

The stick arrangement in a II is nothing like the I.

 

[JoeB]

Hi Jeff,

Now I have ZERO experience in a Sonerai, but the sensitivity of the elevator could be related to the levers (control horns) that your stick and elevator pushrod are attached to. Are these built to plans?

Also, what are the up/down limits of your elevator travel as well?

I just measured my S1 elevator travel at 21.5º 'Up' and 22.0º 'Down'.
The manual states 15-20º 'Up' and 10-15º 'Down, so I will have some adjustments to make there.
Anyways, just a thought that came to mind as I was cooking dinner...might be worth comparing

 

[Schmleff]

I don't know if the elevator control horn is stock or not, but I assumed so when I put it together. The changes to the control column were to address clearance issues with the control rod running through the middle of the torque tube. The seat was not stock either, its higher than its supposed to be by about and inch. However, the turtle deck is 1 inch taller as well.

 

[ncam]

Providing the stick doesn't hit anything, longer is better, enabling finer control movementand better leverage.
It should fall easily to hand when in in cruise and have enough clearance to give full movement.
My 1st sonerai2 had a short stick and was OK, but longer is better
Neville

 

[Gaston]

I had to cut mine on my S2 , because it interfered with my legs...
now it clears below my knees for full travel ,and I like the sporty feeling...

Gaston

 

[Raceair]

A longer stick will give a lighter feel with more movement. A shorter stick moves 'less', but the feedback pressure is higher….I prefer a shorter stick, especially at higher speeds….. I used to fly the Cassutt by gripping the stick about halfway down its length…..

 

[Schmleff]

I'm putting the finishing touches on the new control system. I'll do a write up on my blog when finished.

Neville, I agree, up until a point. Mine had nearly 0 feedback on the stick when slow. When it gets that light, its very difficult to land.

Not only is the new stick adjustable, I also moved it aft about 3". Its aft of the front of the seat frame by about 2 inches. I can now rest my arm on my leg and reach the stick without stretching my arm out. Much more comfortable.

 

[phzabriskie]

Well thank you Sonerai.net again, if this thread had not come up I never would have compared my stick to the plans. Seems Mr. Customize Sonerai adhoc (i.e. my original builder) made the stick 18" high, 5" inches over plans and bolted it a 1/2" down from the union instead of the plans 2 1/2". Jeezz. I find more and more little things like this that tell me he was splap/dash get it together and fly asap whatthehell builder. I cut my stick to plans length of 12 3/4" and will start from there and adjust once N127PZ gets flying. Thanks guys for the attention to details.
-Pete

 

[Bil4381]

Pete,
It really is a fine line. I worked as an aircraft inspector for a lifetime, then wanted to restore by SII. It would have taken years. I've seen any number of builders reach the age where they could no longer build or fly. Typically projects sit until they die.
One of my friends has built a few aircraft and owned say 50 aircraft, most government surplus which he refurbed and sold. Not a few of them were chipmunks. I believe that Art Scholl had a few including one from my friend.
My friend recommended I re-plan the whole thing, determining exactly what it needed to fly safely not to be a museum piece. I did that and flew the same year. It has flown regularly since 2007.
This is just to give you some perspective on homebuilding.
Bill E

 

[Schmleff]

The control system is complete and installed. I ended up moving the stick closer to me as well.

It was a serious pain to get it properly aligned with the wing in the way, but its in and is super smooth ; ) It ended up being about .5lbs lighter and could have been lighter yet, but I used some pretty thick wall tubing that I had on hand.

Mission accomplished, my helmet now fits! Details on my blog at schmleff.blogspot.com

 

[mhflyit]

Well done Jeff - what helmet are you using?

 

[Schmleff]

A modified Chinese Airforce helmet with O2 mask

 

[n3480h1]

So, when you fly, you eat rice cakes instead of granola bars? ;D

Tom

 

[mhflyit]

Jeff, is that just for races or everyday flying?

 

[Schmleff]

Testing primarily, and racing.

 

[mhflyit]

Got it. I've been looking for a low profile helmet - the skiing/snowboarding offerings are about as low profile as they go (some Harley type skull helmets are low profile too) to offer some protection - i don't have more than 1/2 an inch to the canopy. However, I'm leaning towards a rugby skull cap for some impact protection - http://www.worldrugbyshop.com/47525-bk.html. I have a big head : and any helmet is the size of a melon!