Retractable Gear question

[tonyslongez]

I could see this working, but storage in the fuse might be a little more difficult??

Not sure what you mean by that? the whole design is basically a minor retrofit thats how I'm trying to design it:rolleyes: . After all who wants to redo there whole nose section? Not me!

 

steering capabilities as small as 30 degrees would be nice..........hydraulicly actuated??

you know I actually went down that path for about a minute. I was looking at more of a servo driven steering maybe from say, an autopilot servo, but weight would be an issue, I believe that can work. As a matter of fact its easy to setup, have like a little tinnerman wheel on the side for steering just like the big boys do. I'll be finished with the nose gear drawing tonight. It'll be a starting point. No way do I believe its perfect I'm sure one of the great minds who see it, is certainly going to be able to find something I overlooked:envy: I'll render the drawing and post it. Owe By the way the shock I'm using is a rear shock off a dirt bike its inside the upper tube. You can see the spring in the drawing but you won't see the shock itself but it is there, if you swith to 3D wire frame you can see it.

 

Tony

[airwrench]

Not sure what you mean by that? the whole design is basically a minor retrofit thats how I'm trying to design it:rolleyes: . After all who wants to redo there whole nose section? Not me!

 

 

 

you know I actually went down that path for about a minute. I was looking at more of a servo driven steering maybe from say, an autopilot servo, but weight would be an issue, I believe that can work. As a matter of fact its easy to setup, have like a little tinnerman wheel on the side for steering just like the big boys do. I'll be finished with the nose gear drawing tonight. It'll be a starting point. No way do I believe its perfect I'm sure one of the great minds who see it, is certainly going to be able to find something I overlooked:envy: I'll render the drawing and post it. Owe By the way the shock I'm using is a rear shock off a dirt bike its inside the upper tube. You can see the spring in the drawing but you won't see the shock itself but it is there, if you swith to 3D wire frame you can see it.

 

Tony

and the fruits to be enjoyed will taste like, "Ah Jeez, why did't I think of that"!!!!!! Best of luck, I can sence you are on your way

[tonyslongez]

maybe! just maybe!

 

we can incorparate cruise control servos to push pull the steering. This way, if there is to much torque on the gear during landing they will reliquish steering control and now the gear becomes castering again, say we have an indicator light in the cockpit that goes on and off as you have control of steering. Just like cruise control in your car if you touch the gas the little cruise control light goes off hit resume and now your bcak on cruise.

Interesting idea that's all that I have on it right now. just throwing that out against the wall to see if it sticks. Maybe someone can run with it.

 

Tony

[airwrench]

maybe! just maybe!

 

we can incorparate cruise control servos to push pull the steering. This way, if there is to much torque on the gear during landing they will reliquish steering control and now the gear becomes castering again, say we have an indicator light in the cockpit that goes on and off as you have control of steering. Just like cruise control in your car if you touch the gas the little cruise control light goes off hit resume and now your bcak on cruise.

Interesting idea that's all that I have on it right now. just throwing that out against the wall to see if it sticks. Maybe someone can run with it.

 

Tony

.........an over-ride feature........yes, could work but, many times we want some steering when quick exit is needed off runway. This system might stay over ridden in this situation???whaddayathink?

[tonyslongez]

Airwrench

 

we want some steering when quick exit is needed off runway. This system might stay over ridden in this situation??

Well I would think(and I try to be real careful when I do that;) ) if it relinquishes, now your back to just regular castering differential breaking, which does work very well, that is right up untill a break pad fails then your just along for the ride or your spinning in a circle to the left:D the system I have designed is very straight forward mechanical setup the servo "thing" is more of an elaborate setup that does have some promise, if the technology is there to support it in the way of the servo. Which as I said before, the auto pilot servo, or one like it, may be the answere to steering our airplanes electricaly wich would eliminate some of the mechanical linkage.

 

Tony

[airwrench]

Airwrench

 

 

 

Well I would think(and I try to be real careful when I do that;) ) if it relinquishes, now your back to just regular castering differential breaking, which does work very well, that is right up untill a break pad fails then your just along for the ride or your spinning in a circle to the left:D the system I have designed is very straight forward mechanical setup the servo "thing" is more of an elaborate setup that does have some promise, if the technology is there to support it in the way of the servo. Which as I said before, the auto pilot servo, or one like it, may be the answere to steering our airplanes electricaly wich would eliminate some of the mechanical linkage.

 

Tony

BEING ABLE TO MANUALLY CONTROL THE OVER RIDE WOULD BE THE TICKET. AS YOU SAID, WHERE IS THE DATA ON SIDE LOADING THE SPINDLY FRONT LANDING GEAR? YOU KNOW, FOR THOSE GUYS WHO PUT A REAL FAT MOTER ON THE BACK, ONE CAN ONLY IMAGINE THE IMPROVEMENTS THAT CAN BE MADE WHEN WEIGHT IS NEEDED UP FRONT!!(OOPS) LOVE TO SEE YOUR DRAWINGS..........AND HAVE QUITE A BIT OF FACINATION IN THE PROSPECTS OF "WHEELING" MY EZ AROUND WITH SOME PRECISION...

[tonyslongez]

WHERE IS THE DATA ON SIDE LOADING THE SPINDLY FRONT LANDING GEAR?

Well I'm not sure if the side load issue will be as serious as predicted earlier(remember we are no longer using the stock nose gear leg) no doubt it will be there to what degree is still the unknown. I think(Oh here we go again thinking) if the wheel is still able to caster under certain loads and then when those loads are no longer greater than the steering mechanism the steering authority is automatically restored mechanically. so really, we have the best of both worlds.

 

What say yeee??

 

Tony

[Jon Matcho]

...AS YOU SAID, WHERE IS THE DATA ON SIDE LOADING THE SPINDLY FRONT LANDING GEAR?...

AW, please, we like to keep things social around here, so please NO SHOUTING.

[athomp58]

Tony,

Having the steering forces loosely coupled via springs is a good idea. The concept should be that the steering is for small directional corrections during taxi and landing/takeoff operations where it would be easier and more precise than differential braking.

 

The worst case scenario for side loading the gear would be when differential braking is used to attempt turn the aircraft through a smaller turn radius than the nose wheel caster can accomodate. If we can make the wheel caster to + or - about 70 degrees and still be steerable, then the side load issue will not be very troublesome. The nose gear support box structure would be fairly easy to reinforce to take some additional side loading of the gear strut. I'm thinking about a cable around a wheel kind of mechanism to get more steering rotation than a bellcrank mechanism would give. The wheel will need to centralize when there is no weight on it. It's getting late, I need to dream on it until tomorrow.

Aubrey

[CyberSushi]

Hi,

 

I haven't had much time to get down and properly design the main gear yet, so no PDF's or CADs at present.

 

I have been digging around to find out which forks can do the job. I'm thinking about some Ohlin's forks if a stock forks can't handle the load.

 

Seeing as I don't feel like having my main gear collapse under me on landing, I think this is one avenue that needs some serious investigation.

 

As soon as I have something, I'll let you all know.

[tonyslongez]

Aubry

 

dream no more my friend I think (Oh Boy) I have the cure for what ails us .

The preliminary drawing is done in CAD 2000. Everyone who is interested please send me a Private message with your e-mail address. I will send those out. Please let me know in your messsage what format you want the drawings in. If you have a cad program I'll need to know what version. I can convert to PDF but I recommend downloading a viewer as these are in 3D which will really help understand what is going on with the nose gear. All you need is a basic rear shock off a dirt bike one that does not have dampning adjustments. The shock is located in the upper tube assembley. The pin you see about half way down the upper shock tube is pressed into the lower strut leg, this pin slides up and down the slot that is milled into the upper shock tube, this eliminates the need for trailing links. You only have steering when the T is in contact with the steering fork located on the top of the trunion. I haven't drawn the springs that keep the nose gear straight after retraction but they are located on those pins that are stcking out of the trunion. 4:00 AM I have to go to bed I'll finish the rest tomorrow. Good night john boy!!

 

Tony

[tonyslongez]

Hey Guys

 

haven't heard much since I posted my drawings are they that bad?

I have some pics of the nose gear assembly of our 737's. I think the Tiller wheel is the way to go, very easy to rig and a simple install with the existing ng30. I'll post those pics tomorrow. If anyone has any other ideas I could draw them up in autocad and see if we can't get a more refined design. Does everyone understand what they are loking at in these drawings? I haven't drawn everything, I assumed alot, like you have seen a retractable nose gear before. If you have questions please feel free to ask. I'll do my best to explain what you are seeing.

 

Tony

[Steve Innova]

You might consider making the new nose gear with a castering wheel to start off. Once any issues with the strut, shock, and retract mechanism are ironed out, then retrofit the steering mechanism.

 

Lower risk, certainly.

[airwrench]

You might consider making the new nose gear with a castering wheel to start off. Once any issues with the strut, shock, and retract mechanism are ironed out, then retrofit the steering mechanism.

 

Lower risk, certainly.

Nearly astonishing that no one has addressed this issue with diligence until now, perhaps differential braking is a hard habit to break???? Full authority steering at speeds >90mph would be excellent, I am sure that soon it comes to be..........

[tonyslongez]

You might consider making the new nose gear with a castering wheel to start off.

Steve it does caster and it steers. That's what I was afraid of that the drawing wasn't clear enough. As it sits with this design I thought for sure you guys would be jumpin up and down. But sadly that didn't happen:sad: well I'll put it together and I'll take digital pics of it, this way it will be easier to understand. I hope in the end you'll say "OH I get it":envy:

Make no mistake, this is a fully steerable and castering nose wheel the caster happens only if there is enough force to overcome the springs that you steer with. You can use gas shocks and conect them to your pedals. I'm using the tiller wheel its far easier to setup.

 

Tony

[Marc Zeitlin]

Nearly astonishing that no one has addressed this issue with diligence until now......

Why is it astonishing that no one has "addressed" an issue that doesn't need addressing? Infinity has been threatening nosegear steering in their canard for over 10 years, but that's gone nowhere. If there are any canards out there that have installed nosegear steering, no one I've ever talked to has ever seen one. There's a reason for that - it's like trying to exterminate all the giraffes in Alaska - it's really not a big problem that needs addressing.

 

perhaps differential braking is a hard habit to break????

Have you ever flown an aircraft with differential braking, like a L.E., V.E., COZY, Katana, Cirrus, Lancair Columbia or a Grumman Tiger? It's pretty simple. I can spin my airplane in it's own length - try that with nosewheel steering. The ONLY issue with differential braking is taxiing (and the early part of a takeoff run) with a strong crosswind, but there are relatively simple techniques for dealing with both of those.

 

Full authority steering at speeds >90mph would be excellent, I am sure that soon it comes to be..........

I don't know what airplanes you rent, but if you think that you can do any amount of steering at 90 mph using the nosegear, rather than the rudders, you're fooling yourself. The COZY rudders kick in at about 40 mph, and differential braking (or simultaneous braking, as the case may be) works at ANY speed.

[Steve Innova]

Sometimes people want to do things that are different that no one else has tried, before, just because.

 

What I don't really understand is why you need a reason to try to invent something new? As long as it's with your money and you're not trying to sell it, who cares if a comparable product already exists?

 

Everyone says who castering steering is better, but that's a faulty arguement when there isn't an EZ steering nose gear to compare it against. Sure maybe it is, but we won't really know until someone makes the alternative.

[tonyslongez]

Why is it astonishing that no one has "addressed" an issue that doesn't need addressing?

Says who? You?

 

If there are any canards out there that have installed nosegear steering, no one I've ever talked to has ever seen one.

That would hardly indicate that there aren't ANY out there. MARC:irked:

 

Infinity has been threatening nosegear steering in their canard for over 10 years, but that's gone nowhere

So what is your point on this one? Maybe they're too busy building mains.

 

The ONLY issue with differential braking is taxiing (and the early part of a takeoff run)

Well, without either one of those your still in your parking spot, or off in a ditch.

 

Could it be, just maybe, the takeoff distance on these airplanes might be a little shorter if you weren't tapping the brakes all the way down the runway or even halfway down the runway? Would that not be a good enough reason to have some steering capability? Not to mention maybe extending the life of a brake pad or two. How about tire wear? What about brake failure at 38kts? Before your precious rudders are effective.

 

I don't know what airplanes you rent, but if you think that you can do any amount of steering at 90 mph using the nosegear, rather than the rudders, you're fooling yourself. The COZY rudders kick in at about 40 mph, and differential braking (or simultaneous braking, as the case may be) works at ANY speed.

Who said anything about steering at 90kts?

The brevity of your negativity is stifling MARC.

 

I am pleased to announce that Daryl Lueck and I will be co-hosting the COZY Forum at OSH 2006.

I can't wait to see this. I'm sure everyone including myself will walk away with the feeling of enlightenment by, "Nothing will ever work, don't try anything new, don't question the plans", Marc J Zeitlin. I'll be the first in line at that forum:confused:

 

Can't wait to see you there. You'll know it's me because I'll be heckling you out the door.

 

Tony

[Wayne Hicks]

Tony, if nosewheel steering was so good, so important, someone in this long-storied EZ crowd would have already come up with it. The reason most haven't bothered to try is that many of us active fliers LIKE the full castoring nosewheel. We see it as a feature, not a hinderance.

 

But please, by all means. If you feel the need knock yourself out.

[Jon Matcho]

Gentlefolk,

 

Who said anything about steering at 90kts?

Airwrench wrote this:

 

Full authority steering at speeds >90mph would be excellent...

I'm sure you can appreciate how that might catch Marc's eagle eye. Airwrench, sorry, but I don't think it would be excellent at all.

 

The brevity of your negativity is stifling MARC.

I've had the PLEASURE of hanging w/Marc for hours while flying a few trips. I *might* have thought Marc was a negative, confrontational, know-it-all, before those meetings, but after you meet the guy you realize he's one who just doesn't mince words. This I find beneficial -- at least you have an opinion, and when considering a modification like this, the last thing you need is 100% happy talk.

 

There's a reason for that - it's like trying to exterminate all the giraffes in Alaska - it's really not a big problem that needs addressing.

I'd really miss not being able to get analogies like these -- I find them fun and informative at the same time, even if one may disagree with them. Try to think of Marc as throwing a tomato, not a grenade.

 

"Nothing will ever work, don't try anything new, don't question the plans", Marc J Zeitlin.

Well, we certainly don't want that! However, that's more fitting to Nat Puffer, who's reluctance to change anything is what I think is the foremost reason why the Cozy aircraft designs have endured so well.

 

You'll know it's me because I'll be heckling you out the door.

I hope that's a joke... that wouldn't be good for anyone.

 

The reason most haven't bothered to try is that many of us active fliers LIKE the full castoring nosewheel. We see it as a feature, not a hinderance.

Here's a very valid point, and would certainly make me think twice if there was a steerable retractable nosewheel system for the Cozy Mark IV that I could buy for even a lower price than what's currently available.

 

Keep the thoughts flowing...

[Waiter]

With regards to steerable nose wheel, we also need to consider the geometry of the main gear, i.e. tip over angle. With the current plans main gear geometry, I believe it would be very EZ to tip on wing if a steerable nose gear were utilized.

 

There is a very good discussion on this subject at:

 

http://www.infinityaerospace.com/infgear.htm

 

Look down about the 7th bullet in his discussion, good read.

 

Personnaly, on small aircraft, (smaller than Boeing 707) I prefer the caster.

 

The only downside to the caster would be during ground operations with high winds, i.e landing/takeoff during strong crosswind, and to a lesser degree, taxing during a strong crosswind. As pointed out by Marc and others, you learn techniques on dealing with this.

 

To date, I've only had one occation where this was a factor: I had a passanger with me and we landed at Corona to gas up (Corona was noted for inexpensive fuel). Because of a very strong cross wind, I decided not to top off the tanks.

 

Good luck

 

Waiter

[Marc Zeitlin]

Says who? You?

Says all the folks that haven't bothered to implement (or attempt to implement) the modification.

 

That would hardly indicate that there aren't ANY out there. MARC

Point me to ONE, please.

 

So what is your point on this one? Maybe they're too busy building mains.

My point was:

a) It's non-trivial

b) There's no demand

 

Could it be, just maybe, the takeoff distance on these airplanes might be a little shorter if you weren't tapping the brakes all the way down the runway or even halfway down the runway?

Sure. A little shorter, maybe. But if you review aircraft with similar performance (Glasair, Lancair, etc.), you'll see that the TO distance is not substantially different. Most of the difference (if any) can be accounted for by the fact that our aircraft are canards (which intrinsically have longer TO distances), rather than that they have castoring nosegear.

 

Would that not be a good enough reason to have some steering capability?

It might be, if there weren't perfectly good techniques that didn't require nosegear steering and it's associated complexity and weight to compensate.

 

Not to mention maybe extending the life of a brake pad or two.

So, you'd rather greatly increase the complexity, weight and cost of the nose gear, instead of replacing $50 brake pads at the conditional inspection? I can buy a LOT of brake pads for the extra cost of the heavy, strengthened nose gear you're going to need to steer.

 

How about tire wear? What about brake failure at 38kts? Before your precious rudders are effective.

The tire wear difference is inconsequential. Brakes fail, steering fails, nothing's perfect.

 

Who said anything about steering at 90kts?

airwrench. Go back and read his posts.

 

The brevity of your negativity is stifling MARC.

I said nothing about the IDEA of nosewheel steering until airwrench stated that he was "astonished" that no one had dealt with this critical problem in the 30 years that these planes have been flying. If folks want to experiment with modifications that they think will work, more power to them, if they've done enough investigation and analysis to indicate that they can do the modification safely.

 

I was trying to point out that there is no "problem". There are many ways to skin a cat, and castoring nose gear (as shown by the many aircraft, some of them very new designs, that use this technique) is one of them, as is steerable nose gear. Each has pros and cons. Given what seems to be a move (by Cirrus, Diamond, and Columbia [Lancair]) to castoring nose gear away from steerable nose gear, I'd say that the engineering tradeoffs probably favor castoring. Unless, of course, you know more than all the engineers at these three successful aircraft companies.

 

I can't wait to see this. I'm sure everyone including myself will walk away with the feeling of enlightenment by, "Nothing will ever work, don't try anything new, don't question the plans", Marc J Zeitlin. I'll be the first in line at that forum

Funny guy. You've obviously been paying no attention to the 11 years of arguments that I've had with Nat Puffer regarding various modifications to COZY's, nor the engineering analyses that I've done either supporting or not-supporting modifications, as the facts dictate. But hey, don't let facts stand in the way of your opinions - few others do. I've got modifications to my plane, and I've supported others with modifications to theirs, when it's warranted by analysis and testing. However, when someone claims that there's a DESIGN DEFECT with these aircraft when there isn't, I'm going to say something.

 

I think having an objective, balanced view of any particular proposed modification is far more likely to result in success if the mod is attempted, or in a successful decision to not attempt it.

 

Can't wait to see you there. You'll know it's me because I'll be heckling you out the door.

You are welcome to attend and ask questions (or answer them) just like anyone else. You're hardly the first person to object to my pointing out that they don't have a full understanding of the subject of the discussion that they're engaged in.

[Jon Matcho]

You're hardly the first person to object to my pointing out that they don't have a full understanding of the subject of the discussion that they're engaged in.

Marc, these statements are what get other's goats. Me, I'm immune. Others, I'm sure not-so-immune.

 

Also, if I have a question or an idea, I'm damn sure I won't have a full understanding of the subject -- otherwise I'd just do it. If I need to sustain a frozen tomato attack as part of this process, then so be it.

 

Who was it that said something like, "Everyone is disagreeing violently with me -- it must be a good idea!"

[tonyslongez]

Says all the folks that haven't bothered to implement (or attempt to implement) the modification.

Maybe it hasn't been implemented because no one has taken the time to figure it out, just assuming that it was too complex. You know that does happen. It's called initiative, or lack of. There are alot of builders who don't want to take on the necessary mods they would like to have because either they:

 

1) think it's going to be too hard

2) think it's going to take too long

 

Those are just two giant hurdles that most builders have trouble getting over.

 

Point me to ONE, please

.

No problem go to the third page of this thread you'll see two attachments of rendered drawings. There's one

 

My point was:

a) It's non-trivial

b) There's no demand

There you go again, Marc, thinking for everyone else. It's non trivial to who, you? There's no demand? You stated that "Infinity had been working on a steerable nose gear for ten years and that it has gone nowhere".

Now I ask you, who works on a steerable nose gear for ten years if there's no demand:confused: Do you know what kind of money J.D. must be thinking he is going to make to have that kind of fire in his belly to work on something for ten years of his life?

 

Most of the difference (if any) can be accounted for by the fact that our aircraft are canards (which intrinsically have longer TO distances), rather than that they have castoring nosegear.

O.k. sure we have longer TO distances because we are canards- no dispute.

Part of that traditional TO distance has always been with a castering nose wheel which you are breaking as your rolling down the runway. At some point that is going to affect your TO distance. The million dollar question is how much shorter will the roll be without braking at all during the roll out?

 

 

It might be, if there weren't perfectly good techniques that didn't require nosegear steering and it's associated complexity and weight to compensate

.

I'm not sure what your definition of complexity and weight is?

 

So, you'd rather greatly increase the complexity, weight and cost of the nose gear, instead of replacing $50 brake pads at the conditional inspection? I can buy a LOT of brake pads for the extra cost of the heavy, strengthened nose gear you're going to need to steer.

 

Still not sure what your definition of complexity and weight and now cost are:confused: Maybe you have forgotten that you're building a composite airplane. There are alot of strong composite materials on the market that would benefit the use of this nose gear.

 

I said nothing about the IDEA of nosewheel steering until airwrench stated that he was "astonished" that no one had dealt with this critical problem in the 30 years that these planes have been flying. If folks want to experiment with modifications that they think will work, more power to them, if they've done enough investigation and analysis to indicate that they can do the modification safely.

Airwrenches' post, at least to me, didn't seem to warrant you coming out with your guns blazing. If he thinks it's a problem, then, to him it is. If you were really supportive initially, as you claim you are your post would've read,

"Hey Airwrench, I have had pretty good success with my castering nose gear but it would be interesting to see how a steerable nose gear might work on a canard". No, you didn't say anything about a steerable nose gear. That's a good point MARC, and you probably never will. You made mods to your airplane that I'm sure someone asked you, "WHY do you want to do that?" Because you wanted to, that's why. Your own reasons were all you needed. Now someone else wants to do a modification for there own reasons and you're quick to shoot them down. Yeah! That is how the experimental industry thrives. Way to go Marc! Keep up the good work buddy:D

 

Funny guy. You've obviously been paying no attention to the 11 years of arguments that I've had with Nat Puffer regarding various modifications to COZY's, nor the engineering analyses that I've done either supporting or not-supporting modifications, as the facts dictate. But hey, don't let facts stand in the way of your opinions - few others do. I've got modifications to my plane, and I've supported others with modifications to theirs, when it's warranted by analysis and testing. However, when someone claims that there's a DESIGN DEFECT with these aircraft when there isn't, I'm going to say something.

No, I haven't been building for more than a few years now, so you're right. I haven't kept up with your arguments or your engineering analyses. I'm not building a cozy. I don't recall ever seeing the word DEFECT. All I see is a new idea for a steerable nosegear. I wonder how many times you said, "It can't be done." I have several engineer friends in all aspects of engineering and when I want them to check my math or my analyses they always wonder how they didn't see what I saw. It's really funny! The common denominator, it seems, is vision and imagination. Don't tell me it can't be done. Help me figure out how it can be done. Forget the reason why.

 

Off to work now I'll check in later.

[tonyslongez]

Jon

 

No don't worry about us buddy. Guys like Marc have there place in this world. We need the nay sayers to keep the fires lit. God knows without guys like Marc we surely wouldn't be flying airplnes right now, the Wrights Bro.s would've just given up.

 

Tony