I am the 4th owner of Onex 0036 and don’t have the plans.
I was pushing the airplane out for the first startup of my 912 ULS and noticed the rudder and tailwheel are not aligned. I assume this is not a desired condition.
Hi John,
Personally, I don’t like seeing the upper rod-end contacting the bottom washer.
YMMV,
Wes
That lower bend in the rod looks pretty extreme. I twisted my horn a little for alignment. Also I agree with Wes. I made cup shaped washers for clearance.
Edit: you can find my picture here:
Plus my description of how to make the cupped washer.
Going check my Sonex in an hour or two - From aged/poor memory; Should the wheel linkage be on the top of the rudder plate, so that when the tail wheel spring is deflated up (on landing) the linkage moves away from, (not into) the plate, as shown??? 
Thanks, Wes. That’s what I thought.
I like the cupped washer idea. I don’t like the look of the rod. It looks like the bottom bend got some extra bend in it somewhere along the way which would explain it being too short. It’s coming off for some rework.
John
I zoomed into the photo to get a closer look, and this may just be an optical illusion, but I would also take a look at the piano hinge half that is riveted to the aft fuselage cone. It almost looks like the loops might be opening up/stretching open a bit toward the bottom of the hinge. Just verify that it is the type of piano hinge that is not ‘open’ (not sure what to call it) as opposed to the completely closed type that is supposed to be used on the rudder.
I’ll check it out
Good eye. Does the Sonex/Onex plans call for solid hinge on the rudder like the Waiex?
I don’t know. I guess I just assumed it might be the same as the Waiex. Even if not, if the loops are stretching out/opening, that would be a significant problem.
John,
BTW, if you did have plans, you wouldn’t like what you saw for the tail wheel link. Since we have all been making suggestions as to how Sonex could improve, how about providing a good tail wheel link while you’re at it? 
Here is a pic of the Per Plans link beside the link I fabricated. I wish I would have threaded the outside of the tubing like yours is. It’s much stronger. I was forced to fabricate a link because I have taller/non-standard gear. So, I had to lift the tail a bit. So, the supplied link was then too short.
I just remembered, I searched far and wide and finally found appropriate beveled washers.
Wes
Should the wheel linkage be on the top of the rudder plate
Not with an S-bend / offset linkage. Peter Anson has been selling steering rods and has photo examples on his website of proper installation. While this steering rod is not an Anson rod, it is installed in a similar manner.
@4redwings - The difference in rudder position vs tailwheel position looks a bit extreme, but note that you might not want them to be perfectly aligned. Sonex designs don’t have any angle offset in the engine mount, so you very often need a trim tab on the rudder and/or to fly with the rudder pedals not totally aligned (i.e. with the rudder slightly deflected). At the end of the day, you want the tailwheel pointing straight ahead when the airplane is flying straight - at whatever rudder deflection is required for the airplane to track straight.
Also, I agree with others that the “S-bend” in your steering rod seems a bit extreme.
I want to also note that the horn attachment on the Onex is different from the way it is done on the Sonex. I don’t have a set of Onex plans but look at these photos (thanks Jeff) and you can see the difference:
Onex (as seen above):
Sonex:
Here is a video a video where a builder found a problem with his Onex rudder drive plate and it appears the problem was caused by improper linkage set up:
So What Went Wrong? (Lean of Peak Aviation)
However, I also believe the rudder horn design used on the Onex needs to be changed to the method used on the Sonex. The difference is where/how the drive plate for the Sonex is attached to the inside of the bottom rib and the rudder skin (see above photos to compare).
Dunno if this helps …
Dale
3.0 Corvair/Taildragger
Like Wes said, you’re not missing anything by not having plans for this particular detail. The one in the plans isn’t good. Mine is custom made since I have a different tailwheel.
The important thing is to make sure it doesn’t bind for any amount of deflection the tailspring has. The geometry of yours does look a bit off, as does the rudder to wheel alignment.
Kevin does win the “good eyes” award for spotting the hinge. The plans call for MS20257-P3 hinge on the Onex, which I’m almost certain is NOT the solid/closed variety. It definitely looks stretched in the pictures, and I’d worry more about that than the tailwheel alignment.
BTW, it’s wise of you to go over details like this. Being the 4th owner it would be easy to just assume everything is OK.
Rusty
I have a couple of questions. First, is this tailwheel familiar to anyone? Second, why would there be so much negative caster? It does have a lot of trail so maybe that would help ward off shimmy. Still, I don’t like the geometry.
That being said, any recommendations for a replacement?
Also, it looks like there have been a couple of changes to the rudder control arm tailwheel linkage hole position over the years.
By the way, I examined the rudder hinge from the other side and it looks okay.
All for now!
John
I remember when that came out. I just watched it again. The linkage was installed wrong. Too bad I can’t buy a new one like his from Sonex.
That looks like a Peter Anson tailwheel. That’s the upgrade! I recently bought one but have not installed it yet. Tailwheel shimmy is just not a thing in the Sonex line.
Edit: check out this thread.
I’m wondering if the tailwheel rod exits the fuselage at a different angle on the Onex compared to the Sonex (which the Peter Anson tailwheel is designed for if I’m not mistaken). My tailwheel control horn is 12˚ nose down compared to the rudder control horn. I’d be much happier if they were the same. I may try to copy the Anson tailwheel but with the geometry adjusted.
On both of mine, I put a crescent wrench on the tailwheel horn and gave it a tweak for better alignment. That is the original Sonex tailwheel bracket, and the one I made as a copy of the Sonex design but with more ground clearance. My Anson tailwheel is under the bench, haven’t gotten around to installing it yet.
Edit: If you go up this thread and look at the picture I posted, in front of the classic ‘99 Saturn SL2, you can sort of see that tweak in the tailwheel fork horn.
