question on angle of force modification
 

i have some questions in my mind about how to calculate the force transmitted to a specific part of the structure.

at this point im asking just to keep it straight in my head.

anyway here is what i can figure (based on my limited knoweledge)

this is the first part of a very complex question but lets see if i have the pieces right as i go...
the numbers are just for reference to make the math easier

thanks for the responses

RE: question on angle of force modification
 

I am not sure what you are asking. But algebra, trig, physics and calculus was too long ago. It seems you have the trend of values right.

RE: question on angle of force modification
 

http://www.starshipmodeler.com/other/es_naugun.htm

well this is kindof what i am going for in the end (the landing gear) i grew up with this movie and have always loved the look

anyway the ending question is trying to figure out how much forse the shocks will have to absorb at such shallow angles comperd to the main weight

I don't think the plane as is would fly being basically a tailless low wing anehedral flying wing.

could be done maybe but would want to make it an edf model then there would be the problem of intakes for the air :(


anyway just my thoughts

RE: question on angle of force modification
 

I think the landing gear configuration wouldn't work at all.
The plane will nose over when it tries to move, no matter what the shock arrangement or even a fixed stiff gear.
Practically, the wheels should be at the front end of the down strut.

RE: question on angle of force modification
 

thansk for the replies paul, and spad :)

paul;

from what I can tell the wheel is located in the same place as normal so I wouldn't think the plane would care as far as nosing over



these are my sketches showing what I mean
you can se this also in the picture

RE: question on angle of force modification
 

'Normal' set up for conventional gear would place the wheel center @ approximately the leading edge. Your drawings indicate a location behind that----TallPaul is quite right.

RE: question on angle of force modification
 

The sweet spot for the rubber to hit the runway is at the end of a line passing through the CG, 15 degrees in front of a vertical reference line passing through the CG. This is for a hard surface. For grass, the wheels need to be a little further forward and I can't tell you an exact figure.

Jim

RE: question on angle of force modification
 

Leapin Rockets , Dr Huer-- What in the Galaxy is that craft?!

RE: question on angle of force modification
 

Model Airplane News publishes a book called "Basics of R/C Model Aircraft Design". Chapter 16 specifically covers landing gear design. The book is very complete and technical. With what you are trying to do, it will probably be worth the money, especially if you intend to scratch build.

It looks to me the landing gear has two pivot joints. One at the top of the vertical strut and one at the bottom. I would guess that you actually will only need one, at the bottom. The top hinge will only rotate the wheels further backward and not absorb vertical loads. In addition, move the attachment points of the bottom shock upward on the vertical strut, and forward on the lower/horizontal strut. If you are trying to make the gear retract .... I can't even begin to figure that out. What you are trying to make is called trailing link gear, something rarely used, even on real planes, I have seen some on Navy fighters, but I cannot remember which ones.

My last recommendation would be to make up a mock up model just to test the gear.

RE: question on angle of force modification
 

What's the matter Dick, a little behind on Japanese cartoons are you?

RE: question on angle of force modification
 

Nope -just back in the 25th Century---