Scota4570

I know, it's not an engine question. Guys who convert engines and fabricate are more likely to have an answer, I think.

1/4 scale D-7. First flight was today. I am tickeled, it flew great. 39cc EFCO conversion. The tailwheel won't do. It is the type with a single spring that pokes in to the rudder. It does not have the guts to turn the airplane. Consistent with my modeling philosophy, "Why buy it if you can make it for twice the cost and ten times the labor?" I am thinking of laying up several layers of spring steel leaves and pivoting the wheel with a bell crank. The wheel would stick out behind the rudder and two horns would be attached to the bottom of the rudder. Or, possibly running seperate pull-pull lines back into the fuselage and tieing into the rudder bellcrank directly.

Thoughts on my plan of attack? Any better ideas? Where can I salvage or, gulp...buy, appropriate spring steel stock to make the leafspring? Rake tines and recoil starter springs are too narrow.

w8ye

My Feedback: (16)

You may never be sure of how it works until you try it?

Scota4570

I just had an epophony, hack saw blades with the teeth ground off.

w8ye

My Feedback: (16)

Good find

Keep it simple

Scota4570

Here are some photos.

http://www.flickr.com/photos/2063862...7625186517220/


I had been posting on a site for scale RC airplane builders. I guess I had used up my freebie posts, maybe 10, and they cut me off and wanted $20. What the heck is that? Hey it is someone's site and they can manage it however they want. I won't be back and they are not getting any money.

av8tor1977

My Feedback: (6)

I made a couple out of torsion springs from a VW bug. The front of the old beetles, (Not Super Beetles) use a stack of flat spring plates in torsion. Some are about 3/4" or so wide, but four in the set are half that wide, or about 3/8". I bent one of the narrow ones up and used it as a tail wheel assembly and it works great on my 1/4 scale Giles. Sorry, I am not at home so I can't post a picture.

AV8TOR

pe reivers

Blasphemy! The Fokker never had a tailwheel but a skid!

av8tor1977

My Feedback: (6)

I built my giant Eindekker with a skid. Didn't like it. My Fokker DR1 has a steerable tail wheel. I am not that "scale"....

AV8TOR

jtisch

I think it depends upon what type of surface you operate off of. Up here in the Pacific Northwest, most of the flying fields are grass, and tail skids are just fine. I do not, however, like using tail skids on asphalt. As for dirt/ gravel runways, well, they are somewhere in the middle.

Taurus Flyer

Scota4570.

Fokker, so info from the Netherlands.
The tailskid wasn’t controlled by the rudder. The centre position was maintained by rubber bands that also were used for suspension, connected with the top of the skid in the fuselage.
The skate is made of steel to keep track on grass surfaces, very important part of the skid!!!!!
This is my copy of the original tailskid of the DVIII, scale ¼, I think the DVII would not be much different

What to do on asphalt or concrete? I don't know, you need something to keep the track!!!!

Cees

av8tor1977

My Feedback: (6)

The problem is, if you want to taxi with a tail skid, you have to give down elevator, rudder, and a blast of throttle. If you don't coordinate it all perfectly, well then it noses over and at the least you have to go get the airplane, and at the worse you break a prop and/or do cowl/engine damage.

AV8TOR

Taurus Flyer

That's right,
People who can do that we call an AV8TOR, you have to learn that.
I only doubt a little bit about that down elevator!!!!

Cees

Scota4570

I wish I could fly from grass. I live in central california near monterey. It rains only in the winter here, 15-inches of rainfall is an average year. All mown grass needs irrigation. It is not like other areas where it rains throughout the year. Irrigation is expensive at best and imposible much of the time. The crops around here are irrigated from very deep wells. Getting a permit to tap in to the aquifer is pretty tough and then you have to pay for the electricity to pump it. Basically asphalt is all I have and will ever have around my parts.


How about sprung landing gear? On my first landing I bounced a bit and bent the axles. I bent them back, it was OK. I greased the second landing just fine. I am thinking a bungee system might be a good thing. Anyone have links to how others have done this?

bikerbc

av8tor 1977 don't you mean up elevator ? If you give it down elevator it will lift its tail and nose over.. The way I taxi is full up elevator to hold my tail down till I Am pointed in the rite direction for take off then I ease off and let my tail come up and when flying speed is achieved I ease back on the stick

av8tor1977

My Feedback: (6)

No, I did mean down elevator. Like you, I do all my taxi-ing with full up elevator. However, on airplanes with tail skids instead of a steerable tail wheel, you have to give them DOWN elevator and a quick blast of power to raise the tail and allow it to turn when you want to make a turn. If you are not good at it, then yes, you will end up going over on the nose.

AV8TOR

bluejets

Why not drive the tailwheel with an extra servo..??

av8tor1977

My Feedback: (6)

Well certainly, a person could. But the whole idea is in keeping with a "scale" image and having a "drag" like the old airplanes did, instead of a steerable tailwheel. Therein lies the problem in trying to taxi. The old airplanes flew from an "aerodrome" instead of an airstrip. An "aerodrome" was an actual flying field instead of a series of airstrips like we have now. Hence, they could always line up and take off or land literally into the wind. Sometimes (often?), taking off directly into the wind entailed support from the ground crew....

AV8TOR

bluejets

Well, to me it seemed he was asking how to turn the tailwheel.

av8tor1977

My Feedback: (6)

If his tailwheel spring and/or rudder throw are insufficient to turn the airplane, then the "skid type tail dragger technique" should help him as well. Clearly however, if one wants an airplane to maneuver really nice on the ground, a different tail wheel set up is indicated in this case.

AV8TOR