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View Poll Results: What type of gear will (or would) you install
Featherlite Strut 47 45.19%
Infinity Retracts 43 41.35%
Aerocad fixed gear 2 1.92%
Other retract system 12 11.54%
Voters: 104. You may not vote on this poll

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  #16  
Old 02-02-2005, 10:07 PM
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I'm still vacillating on what exactly I am going to build, and want to have it exactly defined before I start. Actually, that's one of my wife's requirements, but that's another story entirely. I really, really want to go with full retracts, but I am having trouble economically justifying them because of the associated known unknowns and other things I have trouble quantifying.

For example, when I take the standard type main, it has the pro's of being simple, cheaper, part of the plans, and always there unless you catch it on a fence (in which case you'll have a lot more problems). It's cons are that it looks stupid, it throws debris into the prop, and the currently discussed shimmy. Oh, and it tends to spread when the plane sits on it. I can't put a price on some of the pros or cons. Sure, I could assign labor costs to what it takes to build and install, but it will still be far cheaper than the retracts. The cost of prop damage depends on the prop that I use, but how do I assign cost to spreading, looking stupid, or the shimmy?

By the same token, retracts have some hard to quantify issues as well. I really want them! If I build a Cozy, it will not be allowed to be called a Cozy anymore. How does this affect the insurability? Speaking of that, how much more would it cost to insure with full retracts, vs. just a nose retract? How much more time will be necessary to build in the retracts up front? How will I be able to afford buying retracts, which cost twice what I paid for my first car (which I put over 100,000 miles on). While I never intend to have an accident, how much will a gear-up landing cost if something should fail? I know a lot of these things depend on me. I fully intend to have a lot of hours logged in complex craft by the time I finish, but this just adds to my costs and time to complete, but since I don't have any of those hours yet, and my insurance is covered by the local club, I have no idea about these costs.

That being said, If I did go retracts, I'd be right there with Drew with a VFR panel until funds replenish. By the time I finish, maybe EFIS stuff will drop to the ~$1-2,000 range.

I'll probably build as plans, but do as Waiter suggests and build in reinforcement and plumbing for a future retract upgrade. That way, I can get into the air at a lower cost to log a lot of canard partial-retract hours. Then, some time in the future when I recover from engine and avionics cost, I'll put in retracts. If I hit the Lotto, this plan goes right out the window.

-- Len
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  #17  
Old 02-03-2005, 11:30 AM
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Quote:
Originally Posted by Clutch Cargo
trailing arm gear on my cad cam program.
I didn't like the looks of it and grass fields were forbidden and there were other valid concerns..... maybe mine.
trailing arm gear - oooooooooo - i like it

grass fields are not forbidden, just make sure they are long enough.

mains are OUTSIDE the arc of the prop., the nose wheel is not, use no tread tires to stop rubble from going to prop

Insurability - hate to say it, but i think that retract is retract even if it is just the nose gear
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  #18  
Old 02-03-2005, 12:50 PM
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Quote:
Originally Posted by Dust
trailing arm gear - oooooooooo - i like it

grass fields are not forbidden, just make sure they are long enough.

mains are OUTSIDE the arc of the prop., the nose wheel is not, use no tread tires to stop rubble from going to prop

Insurability - hate to say it, but i think that retract is retract even if it is just the nose gear
That's right. One gear or five. I don't think it makes a difference for the insurance guys.
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  #19  
Old 02-03-2005, 01:06 PM
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Quote:
One gear or five. I don't think it makes a difference for the insurance guys.
I think you're right - which only goes to show how really stupid the insurance guys are about quantifying risk!
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  #20  
Old 02-03-2005, 04:18 PM
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OK, so insurance difference is a straw man. One objection down.

My understanding was that all three wheels kicked up debris into the prop, with the plans gear. I know that the nose wheel will kick up, but that's what the mud flap, er the speed brake is for. I still give the retracts the edge here, because they aren't in the vicinity of the prop, and a wider track should be more stable.

What other assumptions should I be disabused of?

-- Len
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  #21  
Old 02-03-2005, 04:28 PM
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How about "fixed gear look stupid".

They really dont. The damn plane's got to sit on something, and the plans gear looks about as good as anything. Look closely at a 172 one day.
If you're referring to howe they look in the air - when you're near the ground the gear is SUPPOSED to be down. When you're not, no-one can see it anyway.
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  #22  
Old 02-03-2005, 04:39 PM
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Quote:
Originally Posted by levansic
My understanding was that all three wheels kicked up debris into the prop, with the plans gear. -- Len
That may be true on the long, its gear is stubby(not aerodynamic there for lightspeed makes a faring) and smaller. On the cozy the mains are completly out of the way.
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  #23  
Old 02-03-2005, 07:54 PM
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Quote:
Originally Posted by John Slade
How about "fixed gear look stupid".
...If you're referring to howe they look in the air - when you're near the ground the gear is SUPPOSED to be down. When you're not, no-one can see it anyway.
I think my opinion of the fixed gear is formed from the flying photos in the info pack. Every time I see them, I think of vehicles out of old Danger Mouse cartoons.

I don't think they look bad on the ground, but in the air, it just doesn't look right. Birds retract their gear, it looks more natural.

You're right. Most people won't see them as you whiz by, but I'll still know that they are there, looking stupid. If I do go with fixed gear, I'll paint them sky color or dull gray (wait, that's the same thing here for most of the year).

You're right, a C172 landing gear is not that elegant, but then neither is the C172 itself. They match each other like retracts seem to match the Cozy.

Wow, after rereading this post, it looks like I've already made up my mind and now I'm using non-objective points to rationalize my point of view. Well, that's nothing new I guess, as the cost-effective way for me to fly is by renting out my club's planes as needed. I've already made up my mind though and I want to build, so now I'm trying to make an economic argument on building a plane in the first place. I guess the progression to non-cert engines, wider than plans, and retracts is only natural.

-- Len
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  #24  
Old 02-03-2005, 09:45 PM
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mmmm personal opinion, if the nose gear fails - weekend fix and MAYBE 1000

if mains fail ????????????????????????????????? big buckaroos, my prop is 8,000 alone

I'll get my speed from altitude and ox and my looks - well they they can break a mirror as it stands
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  #25  
Old 02-03-2005, 11:26 PM
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I was fully convinced to go with the plans featherlite fixed main gear. Then the vibration thread started on the mailing lists, and it was pretty apparent it was not an isolated issue. If it gets resolved, and it isn't a systemic problem, then I'll probably switch back. Two things I really don't like are resonant vibration issues and flutter - they can ruin your day when you least expect it. The few extra knots don't excite me, nor does the additional complexity of the retracts. The little bit of fuel loss with the retracts isn't a big deal to me, since the Cozy's range far exceeds mine (airplane endurance is not the ONLY factor in route selection). And to agree with Dust, when I look in the mirror, I don't see any reason to be worried about how it looks... It will take more then retracts to make me look sexy! My choice will come down to which one I think will be the safest and most reliable over time.
Mark
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  #26  
Old 02-04-2005, 10:49 PM
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If one was to assume what Bert has been thinking lately in regards to gear look at his thinking by design since Willians Vjet to SpaceShipOne. It is a 45 degree straight strut (retractable aft). I think the straight strut geometry has less oscillation potential then the old bowed structure in the current design. Also notice he went oleo in the nose of Vjet because it is low to the ground.
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  #27  
Old 02-05-2005, 12:15 AM
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I don't know if anyone, including Burt, know what Burt is currently thinking. The biggest thing I see about his work is that except for being composite, he never let prior knowledge get in the way of coming up with a better way to do something. He doesn't 'think outside the box', he just seems completely unaware that there is a box. Which is really, really cool.

That said, I really like the 'switchblade' gear on Spaceship One. Push button - .5 seconds later, 3 green. No wirring, whining, groaning, etc. I wonder if I can figure out how to do that on a Cozy??? Uh-oh - is this that modification disease that everyone else has? I thought sure I was immune.......
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  #28  
Old 02-05-2005, 12:32 AM
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Quote:
I really like the 'switchblade' gear on Spaceship One. Push button - .5 seconds later, 3 green. No wirring, whining, groaning, etc. I wonder if I can figure out how to do that on a Cozy???
Interesting idea. Of course SS1 has the advantage of taking off with the gear UP and there's no issue of a possible go-around. You'd have to figure out a way to crank the gear up against the spring, but still... it's a thought.
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  #29  
Old 02-05-2005, 01:35 AM
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If you look real close at V-Jet (1998) it is almost identical to SS1 except for closeout fairings. It seems that (I don't want to argue) for a given size/weight aircraft Burt seems to prefer a 45 degree carbon spring as the lightest weight solution for that airframe. He certainly has used oleo and trailing links in other airframes. The bend, twist and oscillation of a flat 45 degree carbon spring maybe easier to model than a bow structure. The bow model allows for excessive oscillation in toe in and out direction.. The 45 degree model resist that yet allows closed to the same spring rate.

If it was not for lawyers and litigation Bert would probably be setting a direction directly. When Burt witnessed how many Vari-eze where still being made he commented "didn't they get the memo on the Long-ez".

Burt is a clever guy and the only way to see the way he is thinking is to study his designs and reverse engineer them. While there have been a lot of chest pounders Burt flown his design into space.
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  #30  
Old 02-05-2005, 03:16 AM
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Thanks for that pd although I don't understand what you said about oscillations etc. I'll go that way myself with my legs.

About 10 years ago, a friend of mine made a one-piece main gear 'bow' himself from carbon-fiber tape. He made a form from wood and laid one tape on top of the next in the form, with resin, until he had the desired thickness. He probably could've applied pressure to the stack but didnt. Also, the form could've been made more easily out of the 2" thick housing foam you can buy in Colorado but not in Alabama.

He added rounded foam to the L.E. and T.E. and covered it with glass or carbon. He easily drilled thru it for bolt-holes for the wheel assemblies and mounting. It was light. I was impressed. So easy and inexpensive. I don't think his plane ever flew (everyone else can be thankful) but it seemed to handle the loads of sitting in his hanger well.

That LongEz with retracts in a 1992 Kitplane magazine, made by a former B-29 tailgunner, also had legs made this way. The gear lifted up and into a slot in the bottom of the wings. I also know of a set of carbon legs like this for RC airplanes which have a tendency to delaminate. The L.E. and T.E. aren't covered in any way.

Last edited by tnt : 02-05-2005 at 12:02 PM.
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