Grove Landing Gear Mod

[Global Hawk]

Hello all,

 

My name is Xavier and I'm currently building a Cozy III at KSUU. So far I'm in Chapter 10 but I'm evaluating the possibility of rebuilding my center spar to include steel plated hard points for a set of Grove gear struts. My website is cozyiii.com and the link below will take you to the mod diagram that I created. I believe the mod will be successful and I read a couple forum entries on the subject. I'd like to get your inputs on this mod and any suggestions you may have. Thanks

 

X

 

http://www.cozyiii.com/Landing_Gear_Mod

[Big Steve]

I have a couple of questions for you. How much glass will it take to strenghthen your spar to take landing loads? Will Moving the gear to the spar move your gear location Aft? If so this will change your rotation speed.Have you consulted and engineer to make sure it is all strong enough? Those are question you probably should look into. Just my .02 STeve

[Lynn Erickson]

Hello all,

 

My name is Xavier and I'm currently building a Cozy III at KSUU. So far I'm in Chapter 10 but I'm evaluating the possibility of rebuilding my center spar to include steel plated hard points for a set of Grove gear struts. My website is cozyiii.com and the link below will take you to the mod diagram that I created. I believe the mod will be successful and I read a couple forum entries on the subject. I'd like to get your inputs on this mod and any suggestions you may have. Thanks

 

X

 

http://www.cozyiii.com/Landing_Gear_Mod

when you say Grove gear struts you mean the bent aluminum fixed gear legs?if so why would it attach to the spar?

[Global Hawk]

Thanks for the responses and here are your answers;

How much glass to strenghten spar? I would assume the same layup schedule as the amount needed for infinity retracts.

Will moving the gear to the spar move the gear location aft? Yes and rotate speed is a non issue since the runways I will be departing are long.

Have you consulted an engineer? That's why I'm posting this on the forum; to get engineer feedback.

You mean the bent aluminum fixed gear legs? Follow this link and scroll down to the Corby Starlet. The gear legs will be made similar to these and will have an 1800 max landing weight capacity. http://www.groveaircraft.com/landing_gear.html

Why would it attach to the spar? I would like to utilize the spar so that I can widen the width of the mains alittle.

 

X

[Big Steve]

One more question????? Why change all this stuff the plane works fine the way it is designed. I built and flew a Longeze it was just fine with the gear bone stock. Are you trying to reinvent the wheel??? Its your time and your money. STeve

[Marc Zeitlin]

How much glass to strenghten spar? I would assume the same layup schedule as the amount needed for infinity retracts.

Since you'd be mounting these gear legs in a different place and with a different mounting scheme than the Infinity gear, why would you think that the layup schedule for the Infinity gear would be appropriate?

 

Will moving the gear to the spar move the gear location aft? Yes and rotate speed is a non issue since the runways I will be departing are long.

Rotation speed (and hence landing speed, to some extent) is not an issue? At all? What if your rotation speed increases to 150 kts? How far are you moving the main axles rearward? Have you calculated the difference in canard loading with that rearward movement? Do you know how much rotation speed will have to increase? Are you willing to truck the plane out of an airport with a 5K ft. runway if you have to land there, because you can't get enough speed to fly it out? Have you calculated the increased loads on the nose gear (that wasn't designed for it) based on the rearward positioning of the main axles?

 

Have you consulted an engineer? That's why I'm posting this on the forum; to get engineer feedback.

Wow. With all due respect for the talented engineers that read this forum, posting a question on a web forum and expecting to get safety critical design reviews is really inappropriate. That said, my engineering judgment says that you should stick to the plans.

 

You mean the bent aluminum fixed gear legs? Follow this link and scroll down to the Corby Starlet. The gear legs will be made similar to these and will have an 1800 max landing weight capacity.

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

Once you look at the gear legs that HAVE an 1800 lb. capacity and landing speed capability close to the COZY III, you've got something that costs two to three times as much as the standard gear leg, is less aerodynamic, requires substantial modifications to the aircraft structure to integrate, provides no advantage other than POSSIBLY a slight weight decrease (although that's debatable), and kills your takeoff performance.

 

Why would it attach to the spar? I would like to utilize the spar so that I can widen the width of the mains a little.

Why? What problem are you trying to solve? Is there some endemic problem with Long-EZ/COZY III landing gear width that argues for wider gear stance?

 

Stick to the plans gear system. Or go with a tested and proven retract system, if you want. But keep the axles at the right Fuselage Station, if nothing else.

[planecrazy]

I have asked about these before here in landing gear section-the are a set that I would like to have I think they run around $3000-$3500 I like the wide stance for sure but I believe I would keep them closer to plans area instead of back maybe beef up that area( just sayin) There is a picture of them in main landing section.

[Global Hawk]

You said it Marc,, Wow.. I don't know if I should thank you for the candid reply or ask you to work on your tact. I really disagree that posting this on the forum for engineer feedback is inappropriate. I've been a member of the forum for a year now and the typical way you respond to entries is the reason why I have hesitated posting. I appreciate some of your responses and I will continue evaluating this topic with my Air Force engineers here in California.

 

Xavier Lawson

Flight Engineer, C-5 Galaxy

[TMann]

Wow.. I don't know if I should thank you for the candid reply or ask you to work on your tact.

Oh I can help there ...... you should thank him.

[planecrazy]

I may not be as knowledgeable as Marc Z. But I said what he did I must be catchin on to how to build a plane safetly I said aleast keep it closer to plans area!! I must have been reading while marc was replying hehehe!! Just sayin:) just goofin marc don't think I'm being a butt.

[Lynn Erickson]

You said it Marc,, Wow.. I don't know if I should thank you for the candid reply or ask you to work on your tact. I really disagree that posting this on the forum for engineer feedback is inappropriate. I've been a member of the forum for a year now and the typical way you respond to entries is the reason why I have hesitated posting. I appreciate some of your responses and I will continue evaluating this topic with my Air Force engineers here in California.

 

Xavier Lawson

Flight Engineer, C-5 Galaxy

thanks Marc, you just saved me a lot of typing. it sounds like you want a wider stance on the gear then stock, if that is your reason to do all this engineering and work I have to say it is a waste of time and money as you will not find a more stable plane on its gear then the cozy 3

and Marc, you mentioned a proven and tested retract system? or was that a proven but not fully tested or a tested but not fully proven system?

[TMann]

Marc, you mentioned a proven and tested retract system? or was that a proven but not fully tested or a tested but not fully proven system?

HIJACK ALERT!

[steve]

i love it when" some" want to fix the cozy. and i hope good luck with that.

i was in Steve rights plane with wider gear and set back gear, on landing he warned me about the" plop"

i was in jacks 1o- 540 and he told me about the "plop" (bang).

both planes are very close to stock (with in 4").

your mite be 15" back(guess) iir.

you will need to buy lots of struts for the front (one per landing)

that spar in 1/2 urethane where you want to bolt to.

in. gear has a 25 bid plate ( 12" by 6" ) iir.

but its horizontal, yours is flat, not the same.

my point is, a hard landing with your concept will have fuel departing the plane and cost a 3000 to repair

the stock way would be 500 and 3 days work.

most big mods will take over a year and be untested

[Kent Ashton]

Will moving the gear to the spar move the gear location aft? [/b]Yes and rotate speed is a non issue since the runways I will be departing are long.

Remember that a Cozy III nose gear is stressed like a Long-EZ nose gear with two people in the front seat, i.e., just barely adequate (It is a LEZ gear if you build to plans). Now you're going to load the nose gear and nose gear box more by moving the MLG aft. What happens now if you make a hard landing or drop her in?

 

A Cozy III already has a longer takeoff roll than a Long-EZ because of the two people in front. Now you're going to make the takeoff roll longer? Nah, don't do it.

[Global Hawk]

Thanks Kent. Well said. I've decided enlight of the above recommendations and concerns to stick with the gear already on the project. Thanks again

 

X

[Lynn Erickson]

HIJACK ALERT!

Marc, mentioned a proven and tested system gear system not the one you are thinking about?

[Wayne Hicks]

You'll find that our fiberglass gear will outperform most metal spring gear. Unless you really botch the landing, our gear tend to make our planes plant to the runway with no bounce. No bouncy bouncy like on a C-150. And although the width of the footprint seems narrow the plane is quite stable during takeoffs and landings. I wonder, are you getting negative input from your AF buddies? Try to find someone and get a ride in one. You'll be sold on the plans method.

 

C-5, huh? That's so cool. I rode on the flight deck of the C-17 taking our crew module from Dryden (Edwards AFB) to Holloman AFB. A very cool ride for a layman like me.