landing gear that can take a beating and not collapse

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crbnunit
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Post by crbnunit »

You'd have to push the main strut forward quite a bit to keep the wheels in the same location. That is a major redesign with lots of fab work.
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aero101
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Post by aero101 »

Not sure but think your math is off somewhere... Wouldn't it be easier buy some progressive wound springs for existing struts, gusset up axle and lwr a-frame area of strut... Personally, I've plonked mine in pretty hard more then a couple of times, and never had an issue with gear, seems that mostly what kills it are incorrect hardware, loose worn out mono bearings, and sideloads. With the big bushwheels, gear hardly moves even in rough stuff? It almost sounds like a helicopter would be your most reliable option? at least you wouldn't have to plan on possible prop strike.... :lol:
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crbnunit
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Post by crbnunit »

I have hammered the stock gear pretty hard a couple of times. It is a strong setup and I have no intention of changing the basic design. I did opt for extended/heavy duty gear but beyond that... I don't want to stifle progress, experimentation or ingenuity though. You never know where the next cool idea is going to come from! The Maule is an excellent platform but it could stand a few tweaks.
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akholland
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Post by akholland »

I would love a chopper till u had to go more that 1 hour flight from a fuel source with a rotor way . Can't hunt with chopper either or even transport gear, I would lose my chopper to fish and game in short order so I'm gonna avoid that game. Waiting on Reeves to open Monday so I can get steel and start welding

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crbnunit
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Post by crbnunit »

It would be fun but those little suckers are EXPENSIVE! Instruction and flight time aren't much better. Last time I looked it was over $200/hr.

Just saw some 35's with extended gear being installed on an M-5 yesterday. Probably as close as I'll ever get.
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Post by akholland »

This is a sketch of my design. A trailing arm suspension just like on a old Polaris vertical edge chassi. I never once broke a trailing arm and I have bent a ton of A arms on sleds. This design is proven. The only thing I don't like is the steep angle of the radius rod which causes the tire to move outward further on landing and increases stiffness of ride quality.

https://www.dropbox.com/s/5gp686sh9ids2 ... 004453.jpg

https://www.dropbox.com/s/7jb7po8192ldt6n/IMAG0355.jpg

The tubing will be the same thick aluminum airstream tube used for float fittings. They will have 1/2" aluminum brackets bolted inside them for the attach points. The This design would require No changes or modification to the airframe.

The most difficult part of this design will be making my own spindles while keeping them light. Everything else is simple.

And if you do hit something, the brunt of impact is on the rear float fitting, an easier area to repair than the primary structural area beneath the seats.

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gbarrier
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Post by gbarrier »

Interesting, is bending at the center of the A frame a common failure?

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Post by akholland »

Only when you drop it in crazy hard. Most of the time it just bends the rear arm, or shears a oleo bolt. Maule gear is as strong as any other aircraft gear. it doesn't have but maybe 3 inches of travel and utilizes 1960s shock technology. Most old planes have Lots of room for improvement in my opinion.

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A better drawing

Post by akholland »

Props to anyone who can make sense of my drawing lol

https://www.dropbox.com/s/vougxisrbr2u2 ... 032126.jpg

Front view.
Two radius Rods, canabee vee system, one shock, one trailing arm. Radius Rods have threaded tie rod end connectors on each end. Trailing arm is solid mounted to spindle. Rear of trailing arm at float fitting is attached using some sort of pivoting ball joint but need ideas on that connection.


Pro
Design also eliminates changes in camber when landing, similar to a double wishbone in that respect. Air shock gets exponentially stiffer as it reaches the end of its travel and is fully adjustable using a air pump for terrain types. Ie: stiffer for beaches to reduce roll.

Con
Parasitic drag similar to a cub design to hold radius Rods.


I just can't see why this design has never been experimented with before. It seems you can find everything under the sun on Google, but not this. At this point I'm looking for someone to poke some holes in this as I'm sure to have missed something.

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crbnunit
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Post by crbnunit »

I like it and have little doubt it would work. However, I can't imagine it won't add quite a bit of weight and lots of extra drag. Not to mention cost and complexity.

All of the real load will be on the trailing link and the shock so all of the other links could probably be aluminum. As far as the trailing link attachment, just make the hub attach a weld or bolt on and a Heim joint at the float attachment.

Right now I'd be happy with a safty cable system.
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Hottshot
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Post by Hottshot »

Ok my .02 Take it or leave it.

First of all I love the "Outside the box" thoughts that's what makes things happen, it also shows us where things can be improved and where there really isn't improvement just more going on. When "We" (Bushwheel of old) came up with the HD Standard gear it was out of a deep need to improve the stock gear with the issue of letting us down and of corse we were working twards the HD Extended gear that is available today.

Now as some one that has been involved with this type of thing in the past a little I will give you some insite on what the FAA looks for as well as what I as a pilot and Maule owner look for.

1)Complexity
2)How far of a departure from OEM is it, and how will it affect the other components involved
3)what kind of testing will it take to make sure it is safe (one to sell and the other for my personal limitations of hauling my family)
4)Weight
5)Weight
6)Drag

Now I know there are things out there like this that are and will be 1 off's that people are not wanting to sell (at first) so repeatably of build don't come into play, but even one off production can bite you. If you build one build two so if you have a boo boo you can get home in a timely manor. The name of the game in STOL aviation is performance. The heavier you are the performance trickles away. You start with a design that weighs 20# (Stock gear) and you have a HD set up available at 22# (ABI HD EXT Gear) that is a huge performance gain for a little weight increase BTW these #'s are just round #'s as I don't have the actual in frot of me. Now I also know of a mod that we were working an at the time that would have negated the extra 2# that was gained with the install so overall for what the HD Gear gave us was a "0" performance loss in weight gain and measurable performance gain in STOL.

So with that thought I still say keep the ideas flowing but don't loose sight of the prize!


Also if you look at the picture of the failed gear leg I would say there is more to that story than most would realize. and before any body gets their fruit of the looms in a twist I am in no way referring to the pilot or his/her capabilities what so ever. Purely a mechanical observation.

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Post by akholland »

The gear above was just plain pilot error, but both gear failed in the same fashion equally. Who knows if another system would have held up to the same abuse.

On another note: I'm curious if an air shock or fully adjustable dual rate tension shock has ever been considered as replacement of the oleo. I see lengthening the travel of the current oleo member as adding significant strain as the gear stance widens. As I think has been discussed before, the 4inch extended gear should make room for some additional travel as prop clearance is available for use.

I definitely don't ever intend to try selling a design, the faa has to many regulations to make things like this worth pursuing for the average enthusiast. I just want to build something cool that nobody else has ever done. Building it and calling it your own is half the fun.

A heim joint is the word I was looking for. And looking at Google photos made me realize I already have all the materials to construct. I'll just shorten up some bent wing struts! Those seems to be readily available in the ol boneyard lol

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Hottshot
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Post by Hottshot »

akholland wrote:The gear above was just plain pilot error
I don't think so and if the other side was set up the same I would bet on it.

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Post by akholland »

The gear was off a 79 model m5 being used on a older m4. I think 79 was the year they beefed up the rear leg member.

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Hottshot
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Post by Hottshot »

Gimme a call i will explane 8)

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