Tomcat

Having already made what was going to be a spare wing for the apprentice & with the weather as it is, I thought I might as well carry on & build the rest of a plane to go with it. I found a battery compartment from my first ( now deceased) Cessna fuz, which just happens to have mounting points for the landing gear built in, so I used that as the start point. Turned around & moved forward it works for a tail dragger.
This will be the first model made entirely with the new foam, mostly 5 mm thick sheet. It is also the lightest, with everything weighed it looks like it will come in at around 50 oz all up, which for me at least is light ! Power comes from a g15 3520 980 kv motor spinning an 11x7.5 prop & rated a 440 watts. 60A ESC with 5A switchable BEC. I will probably run it on 3s, although there is plenty of room for a 4s. The name is taken from the motor make. I thought it quite apt, as most of my builds seem to have a mind of their own & can on occasion be a bit spiteful ! Well at the moment it's going together okay. With the big flaps this one might actually rate as STOL. I decided to add an extra servo tor tail wheel steering.

nice one crash, I do like a project.

Eric. Firstly, I want a tail wheel that steers & is stronger than one attached to the rudder, the extra weight was taken into consideration & included in the all up weight of 50 oz. Secondly, if you look at the first picture you can just see the opening inside at the front of where the battery hatch fits, this was extended all the way up to the firewall. The battery can now be moved all the way to that point. I don't envisage any problems with C of G.

I agree with Eric regards the Steering control. However we all choose what we think best.

Okay, well you guys have far more experience than I, so would you use a fixed or free wheeling one ?

Put the servo up front with pull pull wires to the tail wheel crash

Thanks BB. Say I want to loose the steering all together. Fixed or freewheeling ?

iI would keep the steering

Got some more done today. Tail is finished & painted. Carbon fiber rods to hold the elastic bands are in & most the fuz sanded down. I also had a mess about with some chrome effect paint. Works okay on brown paper, primed with two coats of watered down wood glue & lightly sanded, but I'm not over impressed. Lastly the battery box seen from inside. The ESC is fixed to one side up front. Air flow from a gap under the firewall & up both sides of the box.

crash
Just a mechanical point but two rigid push rods working in opposition is not a sound set up.
The servo and tail wheel arms have to be exactly the same length and parallel to each other or it will bind at some point unless there is sufficient linkage slop.
It is hard to imagine that such a substantial rod couldn't handle both the tension and compression forces on its own.
You would then be free to use the inner servo arm holes if the steering proved to need less travel.

I agree with Q, interesting concept but its asking for trouble imho, another point is that it won't take much of a knock on the tail wheel to strip the servo gears, As Eric has said a castoring tail wheel will work fine, providing your holding the stick back a quick blast of throttle will soon have her turning...
Incidentally I like the chrome effect paint, maybe you should give Martin the heads up.

Thanks lads, now we are heading in a positive direction. Based on the advice I think I have two choices, If i keep the steering remove one of the push-rods ( once I know the right direction of travel) or go for a castoring wheel.
As far as paint goes, I have written reams on it in previous recent & past posts, it's all there for the reading !
Eric Wrote "Learn to land so the model stops near you! "
If it fly's as slow as the Apprentice I could probably catch it on the way past !

crash
Just remember that with a castoring tail wheel a tail dragger is directionally unstable. Once it starts to slew it will continue and get worse until either the air speed is enough for the fin/rudder to correct it or the plane runs out of kinetic energy.
Free fully castoring on a full size tail dragger will lock the tail wheel straight ahead for take off.