<span style="font-size: medium;"><span style="color: rgb(0, 0, 0);"><span style="font-family: Arial;">I want to convert a trainer with tricycle landing gear to a tail-dragger.

I know that the main gear is too far aft as it's designed so how can I calculate where to relocate the main gear on the fuselage?</span></span>


Mike</span>

Uh, the mains would need to be in front of the CG on a tail dragger. But as I always ask on this type of thread, if you're flying a trainer, why do you want to redesign it? Trike gear is great on a trainer, it's even great on an advanced aerobatic bird. Some of my pattern planes are trikes and they land better than my tail dragger scale models.

If you're working on learning to fly, I'd suggest using a trainer and building it as recommended. There's a reason the gear is set up that way. It's easy to fly, easy to land. And if it makes you feel better, there are "real" airplanes with trike gear. Notice how most of the planes you can get pilots lessons in are trikes? Take one guess as to why.

Dave

I would guess he already knows that the gear needs to be in front of the cg. What he really wants to know is how far. While it's true that most trainers are tricycle geared planes, there are other things to consider as well as ease of handling, eg, reduced take-off run with tricycle gear compared to the tail-dragger, better visibility with trike gear, etc. Or, maybe he just wants to move to scale planes and many of those have a tail wheel - even some of the newer designs, eg, Spacewalker/Revolution from 1986.

I sense the tri is getting boring and he is seeking some challenge. I say go for it , that`s how you get better by coming out of your comfort zone. Just place the main gears at the leading edge of the wing. With the plane level to the ground at least half the main wheels should be ahead of the leading edge of the wing when looking down.

Locate the axles of the mains directly under the leading edge of the wing. That is a good starting point. If it tends to nose over too easily, the wheels are too far back. As for the tailwheel - I took a simple wire unit that was intended to insert in the rudder and ran its wire parallel under the rudder and through a screw-in eye.

I made this modification to my trainer and it was a good step. I could learn to deal with a taildragger on a platform with which I was familiar.

Have fun!

Bedford

I converted several trainers to tail draggers. Reason: I always wanted to fly War Birds from WWII. Not many of them are tricycle. Only thing I did extra was to add more surface area to the rudder when converting to tail dragger. It helps when trhottle up is a little too fast. ( Great memories from the late 70's and early 80's )

Read this great article:

http://www.rcuniverse.com/magazine/a...article_id=866

Thanks to all who responded.

Actually, I've been flying RC for quite a few years. I'm also an AMA club instructor.

The reason I want to do the conversion is that a friend and I are building identical trainer kits (with vastly different livery) with identical engines, and we're going to practice formation flying. I don't care whether it's tricycle or tail-dragger (although all of my models are tail-draggers). But my bud wants to make his a tail-dragger so . . .

I would assume that the main axle should be somewhere close to the leading edge; I had hoped there was some sort of formula.


Thanks again
Mike

The late Andy Lennon created this schematic:

I just finished turning this...



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.
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Into this:



I aligned the main gear with the leading edge of the wing.

Tail draggers just look right, don't they.

Bob

grosbeak I like the one you converted, very nice job. I have that same plane and you just gave me an idea. Did you paint it or strip and recover ?. Sharp looker.

Hi Leroy - I'll send a PM so as not to (totally) hijack the thread.

Lnewqban,

Thanks for the diagram. That's what I was looking for..

Mike

You are welcome, Mike.

Best with the conversion project !

John I got your PM, thank you, watched the video and that will be added to my winter projects.

Ok fellows: Andy Lennon's book, R/C Model AIRCRAFT DESIGN page 72-76 covers all of the info you need to locate the landing gear placement for converting in etiher way. The taildragger should have the landing gear at a 15 degree angle forward of the CG location, and the trike gear is a distance BACK at 5% MAC. The figure 5 page 74 shows the model with a 4-6% of MAC(cord). I have been converting most of my models to trike gear location for better ground handling, and takeoffs. Saying this may create a discussion, but I like the control issue with three large wheels on the ground, having one of them in front.

Any questions: [email protected]
retired A&P Mech
AMA410664

One thing buggs me, what is it that makes a tail drager hard to handle on the ground, if gear is aligned properly should'nt it track straight. I have noticed that several at our field have problems keeping it straight on landing and end up dragging a wing tip some tipping ouer. I figured it had more to do with landing skills, there is'nt many working on their landing skills. I have yet to fly a tail dragger so what am I in for?.

A hell of a lot of fun! it's mostly rudder and throttle coordination..did i mention rudder rudder rudder??

"Hey old fart", I see ya sticking your head outa the bushes all over these pages from time to time, glad to know I'm not the only old fart on these pages.

Right about one thing, way too many don't use rudder or rather don't know how to use rudder, jerk it off the ground pulling a hard left and can't land with a light cross wind. Part of the problem is thats the way they were trained. I think it would help some of these guys if they practiced running the length of the runway with tail up and not taking off. Anyway I'm not concerned about it.

Yes, a good many of the WWI and WWII aircraft were tail draggers. I believe the F80 Shooting Star was our first jet fighter and it was tricycle gear and I cannot remember a single one since then that has been a tail dragger. Why do you suppose that is? I could be wrong on this. There may be hundreds that were tail draggers, but I don't remember any offhand.

While throttle and rudder are absolutely crucial, one other problem that hasn't been mentioned is that the main gear - just like an automobile's front wheels - MUST have a little toe-in, about 1 - 2 degrees is sufficient. Without that toe-in the aircraft will wander uncontrollably all over the runway, and will make take-offs and landings very exciting.



AERORICH73, thanks for the input!

Mike

Boy oh boy mike thanks for the invite,yes i would like some input,are you kidding us??

Go for the conversion, once you start flying tail draggers, you will hate to go back to the trikes.