Deullist tail dragger
 

Has anyone here ever flown a duellist in a tail dragger configuration? I converted mine to save weight and gain prop clearance. AFTER I was finished, someone mentioned that it might be difficult to control yaw on take-off, being that there is no prop wash over the rudder. Any opinions?

Deullist tail dragger
 

Hi tool,

I built my duellist as a tail dragger. I redesigned my tail to look like that of a bf-110.

I would think you would still be ok with a single vertical fin. I apply UP elevator during the first part of the takeoff roll. Propwash on the stab with UP elevator should increase the down force on the tail wheel, making tail wheel control a little more positive, at least untill the model picks up enuf airspeed such that the vertical fin starts to do its job (which should of course be well before you reach takeoff speed).

I also keep my initial climbouts very shallow and scale-like, and alow the model to pick up ample airspeed before lifting off. Increases my chances of survival should a lose and engine on takeoff.

A light wingloading helps too.

A few more details at:

http://www.elliotfan.com/temp/duelist.html

Hope this helps,
-Elliot

Deullist tail dragger
 

I have a couple of twin tail dragger's with a single rudder (Westland Whirlwind and UC-78) which are a little difficult but manageable on take off. My technique is a very gradual application of power at the beginning of the take off run (with lots of rudder input) until the plane has accelerated a bit and then add full power. The procedure is something like this: Add power, see what it does, correct, add more power, correct, etc. You do have to pay MUCH attention but it works for me. If you get even a little bit "behind" the plane, abort the run and start over.

Deullist tail dragger
 

Thanks guys.


Hey mucksmear, I've read your web site before with a lot of facsination. I'm fond of the 110 anyway because I "fly" one in an online multiplayer sim called "world war 2 online" where thousands of people select a side and play against each other as airplanes, tanks, riflemen, etc. The game has it's own forums and I once posted a link to your site and there were a lot of ooo's and aaah's after people saw that toy of yours!

Layton- I'll probably find a large field and use that idea of yours of aborting whenever I find myself behind the airplane.

Deullist tail dragger
 

mucksmear great looking plane.

want to aska favor of you.

I am designing a twin engine plane similar to the dualist (except shoulder wing and twin tail) and am not to sure on how to set up the tail bellcranks and such.

can you give me some details on how you got yours working?

do you have any pics of the linkages in "the bones"?

thanks in advance.

Deullist tail dragger
 

Tool, that sounds fun. I used to do alot of flying on Ien's Warbirds. Same sort of thing. Flew the 110 occasionally. Cant beat the heavy firepower from the nose canon!

Thanks Unstable.

I don't have photos of the internals, but I still have the scrap plans I made for all the mods. I think I got the general method from looking at a reduced set of plans for Ziroli's giant B-25 that was published in Scale R/C some years back.

In a nut shell:

Each rudder surface has a single control horn that extends directly forward of the hing line.

Rudder horns are connected together by a music wire pushrod with threaded couplers and clevises on each end (pushrod is inside the horizontal stab, just ahead of and parrallel to the sub-trailing edge).

A short offset piece of musicwire and a clevis is silversoldered to the middle of the pushrod (burried in the center of the horizontal stab). This cleves links to a 90 degree bellcrank, also burried in the stab's center section. Other end of the 90 degree crank attaches to a "Sullivan Gold-n-rod" control cable, to the rudder servo.

Opposite side of servo horn drives the tail wheel, (hence the tail wheel's travel is independently adjustable).

Note: Horizontal Stab is fully sheeted and has a symetrical airfoil section, and was built in two pieces (top half and bottom half, complete with their own half-ribs which looked like flat-bottom ribs). and joined after installing the bellcrank/pushrod assembly).

-E

Deullist tail dragger
 

Tool,
I made it sound like it takes longer than I should have. After you get used to the "gradual power " thing you don't really use Much more field than with a normal take off. In my experience I am usually at full power in 50 or 60 feet as there is enough speed at that point for your rudder to be fully effective. There usually is a pronounced "p" effect pull to the left so you end up using more right rudder than you are probably used to.

Deullist tail dragger
 

Also, just as an eye opener, but not to scare you or anything:

Shortly after the start of my take-off roll, I often find myself holding up quite a bit of right rudder, %75 or more of full deflection. Your results may/will vary of course. My left engine is also slower to respond to throttle-ups from idle, than my right engine, and this is the greatest contributor of the yaw-to-left durring take-off on my model.

As an aside, my 40 sized dynaflite p-51 also requred similar amounts of rudder during the take-off run, but this was due to a combination of the already mentioned "p-factor" as well as effects of the helical prop wash hitting top of the fin/rudder on the left side.

-E

Deullist tail dragger
 

Good thing is that I have counter-rotating props (:

Deullist tail dragger
 

Tool,I think that is a form of cheating :-)

Deullist tail dragger
 

I also have a Cessna UC-78, 100", with gas engines. It seems like the transition between tailwheel-on-the-ground and tail-off-the-ground-with-good-rudder-control is the tricky part. Also, I can't seem to get the engines to throttle up at the same rate. All this has contributed to a few hairy takeoffs. Otherwise, flying is pretty normal, like a single.

The pilots of the full-scale planes have the luxury of independant throttles and brakes to help correct swing on takeoff. All we have is rudder, and you have to be quick with it on a twin taildragger. My next twin is going to be a Messerschmit 110, with twin fins. Hopefully the takeoffs will be easier.

If you go with a single tail I would increase the fin and rudder area by 30 percent or more, or else do twin fins.

Jim

Deullist tail dragger
 

Here is my 18 month old Duelist in taildragger configuration. It works fine, I can't take off or taxi on one engine, but it flies well on one (done it twice). It has ancient Rhom-Air legs that fold forward under the nacelles and hang in the breeze a'la DC-3. It has OS 46LAs and weights 11lbs. 6oz.

Deullist tail dragger
 

Nice color scheme LinerDrivr. Nacelles look nice and clean too with your cylinder heads in the horizontal.

Cheers,
-Elliot

Deullist tail dragger
 

Linedrivr, I like the forward folding, DC-3 style retracts, sounds interesting.
Jon L