New Super Cub suspension system

[ksecub]

With all the controversy of the AOSS system, why not get input from all the supercub.org users and come up with a better experimental system. The AOSS system is an improvement over the old bungee, but by no means is it the ultimate solution. Why not get everyone to submit design concepts for a new Super Cub suspension system and we collectively design a better mouse trap. If a good concept is presented, I will donate my engineering time and resources to generate detail manufacturing drawings with a BOM and supply them to the group free of charge. My only motivation is to have the ultimate suspension system for my own experimental Cub. I will not assume any liability for the system, I will only supply a drawing package for you to build off of with lots of disclaimers.

If a good concept is submitted and detail drawing package is generated, maybe we could talk Steve J. into putting the drawings on Supercub.org. Steve could charge a nominal fee for the drawings if he wants for his efforts and it could help to support supercub.org.

I think it would be cool to design a system collectively and put all our mental resources together as a group, rather than pick apart one another. I will start things off with a couple of concepts that I will put in the photo section. The only way this will work is if people participate in the design process. All you arm chair engineers get to work!

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[Bugs66]

Sounds like a great idea. I was planning on buying Larry Bauer's experimental system. It's a dual die spring that is fully adjustable. Larry Bauer makes some great stuff for us experimental folks. Not sure if he plans to share any drawings or not but his prices for the completed product are very reasonable to begin with.

Curious to see what comes out of this.

 

[Bugs66]

Also good for research is the system used by the Bearhawk folks, designed by Bob Barrows. Oil dampened die springs. I was thinking how it could apply to the Cubs:

http://www.mybearhawk.com/fuselage/gearstrut1.html

 

[behindpropellers]

Also good for research is the system used by the Bearhawk folks, designed by Bob Barrows. Oil dampened die springs. I was thinking how it could apply to the Cubs:

http://www.mybearhawk.com/fuselage/gearstrut1.html

Im sure these guys would love to make an airplane shock:

http://hygearsuspension.com/

 

[Grant]

Do a search for "Rock Crawler" on google and look at some of the suspension parts they use...pretty much bullet proof. I would take a design they are using for the dampening. A good example is that Maule that was re designed to use auto suspension parts. Tons of technology is out there. The ting is how do you adapt current technology to be light enough and strong enough. that is the challange.

Here is some technology from fabtech

 

[behindpropellers]

I like this design. The only problem I see with the current system is keeping the suspension part from moving fore/aft. I would think you would have to brace the pivot point on this system:

 

[Ruidoso Ron]

You might be interested in studying the technology developed by Carter Copters.

http://www.cartercopters.com/landing_gear.html

 

[ksecub]

I just got a call from Burl's attorney today. Is it coincidence that I posted this thread today or is it my association with Mikeo? I might have to join Mikeo and remove myself from this web site.

Part of me is mad with a renewed desire to come up with a much better system, another part of me is not wanting to spend money defending myself against Burl and his attorney.

I should just take a deep breath, laugh and feel honored that Burl is somehow threatened by me.

 

[ksecub]

Tim,

Thanks for the input. Your concern is the stability of the bell cracks fore and aft. I don't think there is much load if any, fore and aft along the axis of the fuselage parallel to the engine crack shaft. I think all that load is taken up by the landing gear vees. The original bungee system and all the systems that followed have very little if any support fore and aft.

I think the problem with this concept is the limited space available for the gas shocks. The other concept I presented allows more room for the shocks. Just to clarify, the concepts I presented are not great. The idea is to present concepts to spring board off of. If enough concepts are presented, we can pull ideas off one another and generate a sound, good design. I have used this brain storming, concept generating system in the past with good results, the key is people need to participate. Present your ideas, good or bad, we should not criticize ideas only highlight their weakness and build upon them.

I am in favor of the gas filled shock that can be purchased off the shelf. The problem as I see it, is that all the shocks I have seen are designed for compressive loads and we are dealing with loads in tension. So, if we want to use an off the shelf unit we need to convert our tension load into compression. I don't have all the answers, that is why I am asking for help, and in return we should all have access to an affordable great system.

 

[On Patrol]

Hey Tim,
Have you looked at the compact shock made by Olin for snowmobiles. I have a friend and machinist up in Maine that has actually become a self made expert when it comes to these shock suspensions. He is a dealer for Fox and Olin and rebuilds their units along with many others. I know when I purchased a snowmachine and was dissatisfied with the suspension he was able to adapt and come up with a fix...Good ole Yankee ingenuity.
Let me know what you need as requirements so I may involve J A-Z.

Disclaimer: I do not know Mikeo and I have met Kase only twice (My opinion:Great Pilot and appears to be a Great Guy). I have purchased a magnum tailski from Burl Rogers and have met him at Osh Kosh( My opinion: Nice Guy and I am very happy with the Tailski). I have never had any dealings with Burl Rogers attorney and do not ever want to deal with the man( My opinion: he is a lawyer and has no business on this member site because all lawyers are like nuclear weapons
All the big guys need them but once you use them it SCREWS everything up)....However I am an American and I live in a free country so I can invent what I want and I say as others have in NH "Live Free and Fly"
John

 

[joecub]

Sign me up.... I would love to find a better system for my smith cub.. it works well but i'm tired of the sqeaks and bangs...kse your idea looks like a great start... Joe

 

[kase]

Disclaimer: I do not know Mikeo and I have met Kase only twice

Hi Kase,
Sounds like a great idea

I think you guys might be confusing me with ksecub.

 

[T.J.]

ksecub:
So, I guess if we post any improvements on the suspension for a Cub, we can expect a call from a lawyer?
Are you at liberty to tell us what the lawyer had to say? Wonder who hired the lawyer! :evil:

 

[On Patrol]

You are right Kase I am confusing you and I apologize.( In my opinion you are still a Great Pilot and a nice guy)I have met and if not mistaken a banner tow pilot out of Cape Cod or what use to be known as Marstons Mills....
John

 

[palhal]

Doug-----I owned and flew a Fi-156D Storch for years. It could be landed in a full stalled condition from any altitude in emergency. It wouldn't take much to put the same type compression oleo on the Cub using the lower motor mount, lift strut attach area and front wing spar attach area for the triangle brace with the oleo in between it and the stock gear.

The oleo was a ringed piston with holes moving thru oil and resting on a taxi spring. Very simple. The only problem is the additional weight which we are desperately trying to eliminate.------Palhal

 

[freestone]

On that suspension drawing, it looks vaguely like the rear triangle of a mountain bike - i wonder if any of those horst linkages or 4 pivot point ideas can be used along with the rear fox and other shocks they have?

Regarding Burl's lawyer, I assume it has to be on something other than this post.

 

[Hoonahcub]

AOSS system`

Since Burl likes to sue everyone who disagrees with him, I won't give him the option. I have no intention of buying any of his products.

 

[Bugs66]

Disclaimer: I do not know Mikeo and I have met Kase only twice

Hi Kase,
Sounds like a great idea

I think you guys might be confusing me with ksecub.

Sorry about that to both of you! I fixed my original post. I goofed.

I like the idea of an "open source" landing gear for our Cubs! Keep this going!

I think we should look around for a tension-shock instead of converting compression into tension. Mainly because I see a lot of frontal drag and complexity. I know, what's the difference for frontal drag on a Cub? Still, shouldn't be ignored. Why is a PA-12 so much faster than a Cub? Part of it is because it is cleaned up quite a bit more.

 

[kase]

Thanks, I didnt want people to be think I could actualy invent something

 

[geoffmeyer]

Kase,

I was after the same thing. I wanted a modern emulsion style shock (no heavy coilover) that has rebound and compression dampening. I finished this project a month ago:

http://sparky.supercub.org/photopost/showgallery.php?cat=514

The gear is setup like a Storch or Pilatus Porter, only the shocks are from a modern off road racer.

http://www.racerunnershocks.com/
Look for the 2" air shock. It is perfectly suited for the weight of a Supercub.

The downside of this system is it may not bolt into existing structure - requiring a modification to the tube structure.

I'm biased because I put so much time into it, but I'm happy with the results so far. If you'd like more info, send me an email. You are welcome to come out & fly it to see what you think.

gameyer@comcast.net

Geoff

 

[ksecub]

The attorney was hired by AOSS, I assume. I think the guy was fishing for information regarding the thread that got mikeo in trouble. I made the comment that I got a suspension system from a friend. What I should have said is: I plan to get a system from a friend. I have never bought, sold, distributed, built, or designed a copy cat system that infringed Burl's patent. The attorney said he was searching for facts. I have not dealt much with attorneys and I probably talked too much. This is a great country, don't get me wrong, but people should not be able to sue, harass, or threaten people without having physical evidence. I am a friend of mikeo, I am an engineer, and I misspoke on this web site so I guess I am guilty. Lesson learned, be careful what you post on the web

 

[freestone]

delete

 

[ksecub]

Hello Geoff,

I am a flying buddy of Greg Miller, Greg has been keeping up to date on your machine. Looks very cool by the way.

I looked quickly at the 2" air shock. The web site does not give any force vs. deflection data. Do you know were I can get this type of data? How much do these units cost? I want to keep the system affordable so that the average experimental guy can afford it. My hope is to develop a system that can be built for half the price of an AOSS system.

The system on your aircraft looks appealing, but I would really like to stick with Cub type gear vees. I would like to come up with a direct replacement for the caban vee, hydrosorbs, and shock struts. I would prefer to use the existing fuselage fittings and not require the need to modify the fuselage at all. This really limits the design possibilities, but I think the system would not have much appeal to other users if the fuselage required modification.

Thanks for your input!
Doug

 

[ksecub]

Hello John,

I am not familiar with the compact shock made by Olin for snowmobiles. Can you post some more info or pictures? I am very interested. I think a compact shock would be ideal.

Doug

 

[T.J.]

delete

 

[Grant]

TJ,
I mentioned in another thread about how much the insurance folks wanted for my Aviation Software E&O insurance 40K Annually. It is a shame that the lawyers and insurance companies are getting rich off our industry. I don't know burl or most of you all for that matter. But the one thing that has always been consistant here is our opinions. I sure hope that we dont lose any opinions here for fear of legal harassment. I for one don't really care if an attorney calls me. I'll talk to him all day long and run up somebodys legal bill.

 

[Gordon Misch]

Two thoughts:

1. The open source concept is thoroughly intriguing - I think there is some deep truth hidden in its structure that mandates first-rate products. Witness Wikipedia, Linux, and the non-microsoft web browsers. Truth and elegance seem to surface, maybe just because they aren't restrained by bureaucracy. This is a WONDERFULLY smart idea, except - if there is to be an STC, that requires $$, and there should be a return on the investment.

2. Re the design. I think a weakness in the supercub design is the cabane vee / strut interface. It is inherently weak in compression, especially if there is any misalignment between the components. The fuselage fittings, lower cabane fittings, and gear-leg fittings must lie in a plane. If they don't the tendency to buckle increases linearly (? I haven't pretended to any pencil and paper analysis here) with any offset. If there is a way of eliminating the transmission of moments, and/or of stiffening the fore-aft freedom of the linkage, it could probably be somewhat lighter in weight. In other words, I don't think the tensile properties of the system are limiting; I think it's the compressive properties.

I just read this thread, and I'm impressed. These are off the cuff ideas, that aren't intended to more than that.

Thanks for proposing this mode of design! I'm willing to dig in, if it could be helpful.

 

[gdafoe]

I will make a couple recommendations that I have made in the past. First, I would suggest using the member to member area for posting some more sensitive subjects as this is restricted to viewing by other members - not the whole world. At least you KINDA know who you are posting too, but there are no guarantees.
sj

This thread should be moved, or it will be squelched. It appears someones already working to that end.

 

[ksecub]

Hello Gerald,

We need this thread to stay very public, the whole point is to get a lot of input and ideas. What are you suggesting?

Doug

 

[dpearce]

Hello Gerald,

We need this thread to stay very public, the whole point is to get a lot of input and ideas. What are you suggesting?

Doug

Open Source development has the added benefit of making it very expensive for lawyers to chase as it distributes the workload and therefore multiplies the number of calls/inquiries to be made. Even MS was loath to chase the developers of linux as the numbers involved stretched into the 100's then 1000's spread across the globe.

I think you'd be better getting an email thread going among interested parties. Then you can all participate, come back to this forum with questions if necessary but keep the goings-on "hidden" from view while involving a large number of people. You want a large number of participants but not necessarily a public activity until a critical mass/inertia is reached. The less ammunition you give the lawyers to track you down the better chance this activity has of taking on a life of it's own which is what you want.

These attempts at intimidation are common in patent defense. I am assisting in responding to two letters from lawyer types for my current employer along this line. They hope to accomplish two things typically: 1) Squelching competition for fear of legal action and 2) obtaining licensing revenue from folks who don't want to fight the legal fight. It is a BS way to do business but is most commonly done by firms whose revenue is largely or soley dependent on the existance of the patent or a limited product line based on the one patent.

In my case the stated claims are very obviously bogus when dug into but in the infringement letter they mention that all will be forgotten if we pay a 6 figure licensing fee. It's legal extortion.