I have been building a 4*40 and have a concern about the tail wheel.

I noticed the plans calls for the tail wheel assembly to be inserted in the Rudder fin. I may be incorrect but it appears when landing a considerable amount of force will be applied to the lower rudder CA Hinges. WHEN, I have a harder landing will the hinges be strong enough to take this force? I have apprehensions allowing this very important Rudder CA hinge to take this abuse over time. I already glued and inserted the Rudder Assembly into the fin with additional CA nylon.

What have others seen or done to maybe offset this concern, or should I not worry about it?

Thanks for any advice.

Matt

I agree with you, I dont like the idea of the landing force concentrated on that lower hinge. It will work depending on how well you can land your plane but I just dont care for that set up. Go with a Sullivan tail, it puts the load bearing on the aft fuse with a coiled spring to the rudder-the best method I use on all my planes. This also puts less stress on your rudder servo as well. Good luck and the 4* is still one of my favorites.

The stock tail wheel arrangement will work. What usually happens
is the supplied wire will break. I went through this with my Sig Midstar.

The stock tail wheel wire eventually broke and I replaced it
with a Sullivan unit. On my next plane (Sig Somethin Extra)
I went straight to the Sullivan.

If you have a nice smooth field and always make nice
smooth landings the stock arrangement will be fine.
But if you have a rough grass field go with a Sullivan.

Mike Hammer

The method called for will generally work. Just make sure you reinforce that area with thin CA and fiberglass tape. I think the instructions show this if I remember correctly. If you have mostly good landings, you most likely will have no problems. Of course, many people (i.e.: me) don't always have perfect landings. Over time, this can be a problem. I broke the rudder hinges on my Somthin Extra ARF this way. I am replacing that plane with a kit built version and I plan on using a Sulivan or similar tail wheel.

Or you can be inventive. Get a sullivan tail wheel I believe I swaped out the tail wheel wire for a 3/16 wire. Added a collar and a small piece of brass strip a matching pair of rudder, elev. etc. etc control horns and a small strip of 1/64 ply for reinforcement between the control horn and the rudder. a couple small springs to keep the shock from bumps getting to the servo. My first attempt at uploading photo's hope they show up. made an ooooops That was a dubro .60 tailwheel bracket..


Egor

Don't take a chance on the supplied tailwheel. Go with the Sullivan setup, use the light spring that comes with it and you will be in great shape. Everything goes together fast and easy, it looks good and works great. The best $8.00 you'll spend on your 4*!

Thanks for the input, I ended up removing the factory tailwheel from the rudder with no problem, it was almost too easy to remove (sorta scarey considering its purpose) and then attached a Sullivan spring mechanism.

I am working on sanding and covering now, I will be uploading pics of the completed project soon.

Matt

Ok, I made a Bone head move here.

The sullivan wheel was outstanding, until I had some glue drop down in the pivot point and now it is very stiff!!! Is there a decent anti-glue chemical that I could "rinse/clean" the rear wheel assembly?

ugh..

If it was CA glue, try some debonder or a little acetone.

I think the plans accurately shows a Dubro tail wheel unit too. I haven't looked at mine in a few days. I like those better due to their more compact size. I just put one on a plane a few weeks ago. I think they are half the price of a Sullivan. I've used both.

I have a Somethin Extra that has taken a beating by the guy who built it and from me. It uses the wire in the rudder method. It worked well with CA hinges, even though I don't trust those, and now with pinned nylon hinges. I was doubtful too, but it works really well and is light. I need to build a new rudder and I'll use the same method.

I've used the tailwheel mounted in the rudder in several planes with no problems. The SE was the first to break. It was the ARF version of the SE and the hinges weren't the regular Sig Easy Hinges, they looked completely different. This different hinge could have been the problem. Still, I think I'll use a Sulivan or Dubro tailwheel on the SE kit just to be safe.

It very well could be different hinges between the ARF and kit. The wing tube is different and not interchangable.

I have to do all of my landings tail low due to the 12.25" prop, so the tail wheel takes it hard most of the time.

I've been flying my Four* for the last year or so with the stock tailwheel configuration. I fly off a grass field and have had more than a few "crash and dash" landings. The first problem with the stock layout was having the wire break through the balsa on the rudder. Not too much of a problem if you harden the balsa with CA. The bigger problem has been predictable ground tracking. Originally it tracked pretty true and I even won a fun fly event that required accurate ground handeling. The last few month's it's been a lot harder to handel on the ground. I'm not sure if it's the small wire size or a propensity for hard landings in adverse conditions, but it seems like the steerable tailwheel defeats the KISS principle. I'm getting tired of trying to align the tailwheel to the rudder. My Dad scratched a Four * and used a free floating tailwheel and it is much more stable on the ground. As a matter of fact I looked at all the planes in the basement and garage and they're all tail-draggers and almost all of them have free floating tailwheels. Another option if you want a steerable tailwheel would be to isolate it with a piece of fuel tubing at the connection to the rudder.

I have a question? How did you guys mount the Sullivan tail wheel? did you use the blind nuts. I am working on a 4* now and the does not seem to be any room for the blind nuts in the tail section.

Thanks for the help!

I used four small wood screws to hold it on. Use ca to harden the wood. Mine has lasted years like this.
MikeB

MikeB is on the money!
Attach the bracket using all four screws, remove screws and put a drop of thin CA in each hole. Let it harden, then attach bracket again - this time it is in solid.