Scale Pitts S1-T, S1-S, and a Challenger.

[acerc]

Maybe this will better describe what and how. The black line is the leg and turns into the ply. The yellow line is the axle and support. The white line is a piece tying all three points together.
I am only looking to replace the axle wire, thinking of cutting it with 2" remaining to tie to instead of having to make the sharp bend.

 

[Snoopy1]

Ok now it is making a lot more sense. But still have one more question. The yellow line is the wheel axel then bends down towards the fuselage and then at the fuselage it turns across the bottom of the fuselage back to black landing gear wire. Ok this is the critical part where the yellow wire bends from the leg going down to the fuselage and across to the black line, at that bend in the yellow line is it fixed or hard mounted to the fuselage.

 

[acerc]

Same pic but more arrows. Looking at the red arrows pointing to the outward bends on the legs, those go through 1/4" ply. That is the only point it is affixed the rest set's on a ply seat, noted by a circle with a stick arrow. A bungee cord wraps around the legs and the bolt with washers and that is all that holds it in.
I am thinking about cutting the axle where the green arrow is and just brazing axle wire to the cut piece and the legs.

 

[acerc]

Basically replacing where the green line is in this one.

 

[Snoopy1]

Basically replacing where the green line is in this one.

Ok I got it now the design is excellent and should work. The gear pivots on the two black lines and is held back by the green line which is tied back to the plane by a bungee cord. At first I thought the suspension was solid but it is not, and should work properly. And to the question of cutting the green leg at the arrow location will work just fine. That leg is only under tension and therefore it will not buckle and will work. If I may suggest that you make a steel sleeve drill some very small holes in the sleeve and then brazing it all together the small holes allow air to escape and you can see if the brazing material has worked it self all the way down the joint.
Another suggestion hope you have looked at a few racing car frames. It all bends and connections they add a small gusset plate to hold the angle and to give connection strength. This small gusset plate at times will double the strength of the bend or connection. If you can braze a small gusset at the bend of the wheel if it possible that would be a big improvement in strength of the bend and axel. When you cut that part and replace it with 9/32 diameter wire it will improve the bending strength by 40%.

 

[acerc]

I understand and can do the gussets and link. So, do you think 9/32 cold rolled would suffice or should it be music wire. My problem with music wire is I can't find any larger than 1/4", without being to large.

 

[Snoopy1]

I understand and can do the gussets and link. So, do you think 9/32 cold rolled would suffice or should it be music wire. My problem with music wire is I can't find any larger than 1/4", without being to large.

If you can give me the properties of the cold rolled material and the diameter then I can compare it 1/4 piano wire, and give you an answer.

 

[acerc]

If you can give me the properties of the cold rolled material and the diameter then I can compare it 1/4 piano wire, and give you an answer.

It came from a hardware store and cost about 3 bucks, lol..... That's about as much as I know Snoop.

 

[Snoopy1]

Ok did sum assumptions. The wheel is spaced 4 inches from the bend and the piano wire we are buying from the hobby store has a yield stress of 280,000 psi that is best info I can find on the material. I assumed the cold rolled material that you are buying to be about SAE-1045 that is pretty good grade of steel. The calculation are based on the piano wire at 1/4 and the steel at 9 /32 diameter.
The results are as follows that it would take 107 pound force to bend the piano wire. And it would take 25 pound force to bend the steel wire.

If you need more details let me know.
Please note if the material you are buying is for example like heigh grade socket head bolt which would take the allowable stress up 120,000 psi for steel the number would be 65.6 pound s.
I hope this helps you just trying to show what kind loads you can tolerate and how sensitive this is on the material you are able to buy.

 

[acerc]

Thanks Snoop, that all sounds about the way it feels on the bender. The cold rolled was too easy to bend, the music wire was harder but does not appear to have over stressed it. Before I do anything with the gear I am going to call TNT and see if they can make gear for this weight.
If not then it will be the 1/4 music wire brazed together. I have done many gear like this just smaller gear, smaller wire, and less weight.