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Main landing gear retracts


tonyslongez

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  • 2 weeks later...

Here are my main retracts. The retract side plates would be ideal if I could keep them square, however, I don't think that is going to be the case. I will have to model them closer to the older style Cessan 210 gear that I have. The difference will be very obvious when you look at the other pics I have posted.

 

Tony

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Here is what my "210 type" mains might look like. The top and bottom bulkheads will more than likely be aluminum. The front bulkhead I want to make from birch glass and carbon. The rear bulkhead will be the extended lower portion of the firewall. I'd rather try to find away to make the square retracts work simply because they will be easier to machine than the "210" type.

 

Tony

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  • 3 months later...

Hey Tony, did I ever tell you how much love your rendered models ;)

If you really are looking to include a baggae pod of some sort, and don't like the conventional wing mounted designs, have you considered a conformal design under your (some-what long) intake moulding? It can be made wider without much depth, therefore not creating a clearance issue.

I would however recommend making an assessment of any aerodynamic affect it may create.

All a little off-topic, i know.

Cheers,

 

Bruce. :cool:

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Bruce

 

Glad you like the drawings. I'm still having a time learning all the new stuff Rhino can do. I'm still importing some pieces of the airplane into Rhino from Auto-Cad. I really like drawing in A-Cad becasue I'm more familliar with the drawing enviorment. Rhino is by far a more powerful program, not as powerful as say solid works but I think it is a little more user friendly than solid works. That's my next program to learn. Anyway I'll keep em coming time permitting so everyone can see what I'm up to. As far as the bag pod. I think it looks really cool this way. I do like the idea of making it a little more conforming to the scoop. Certainly will give me a little more room for another pair of the old ladies high heels. I'm not sure if there is a clearence issue or not. I'll have to measure the belly at full gear deflection with a flat tire and see how much room I have

 

Tony

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  • 5 months later...

Here are some pics of the newly designed actuator and side plate. After much debate with my engineering buddies:irked:. I was forced into a new design. (Apparently the guy that has been designing landing gear for the last 25 yrs was right).:irked:. I thru out the last design, which you can see in the earlier renderings. (The trunion for that design is now a very nice boat anchor):D .

 

What I did is exactly what I didn't want to do the first time around, that was to model the gear after the Cessna 210 or 172RG. After several sleepless nights and many hours of stress analysis in solid works. I have settled on this design. (much to the delight of my friends). I took what I believe to be the best features of the retracts designed for three different aircraft based on relatively the same gear geometry and kinematics. Those aircraft are the lancairIV, cessna 210, and 172RG. These three types of landing gear have the same basic parts design.

 

As I progress forward with the gear layout, I will keep posting my results. However! I will not be posting very many pics on the install. These landing gear have cost me alot of money and time, to just give away my design good or bad will not benefit me and may injure someone else, and I certainly don't want that. If after several hundred hours the design proves to hold up, I will be more than happy to share what I know.

(you guys know that);)

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Steve

 

Sorry, about the turn around time for your gear. If my gear perform as well as I hope they will, I think these will be the way to go. they are much easier to machine, and they are almost a bolt and go setup. I'm not going to be the one to produce them, but I will have the drawings available if someone wants to send them to a machine shop and have a set made.

 

Tony<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

 

 

Waiter

 

Yes I would definately be interested in using your controller.

 

 

 

Tony

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Tony,

 

When you get some free time, think about how your going to control the mains, i.e hydraulic. Pumps, valves, etc

 

Also, what will you do to sense UP and DOWN, i.e. microswitches or hydraulic pressure or some combination.

 

Also, Is there anything else that needs to be monitored or controlled, i.e. gear doors, sensors or actuators.

 

WHen you want to talk, give me an e-mail or post here and I'll send you my ph #

 

Good project

 

Waiter

F16 performance on a Piper Cub budget

LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract

visit: www.iflyez.com

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Waiter

 

Here is what I plan to use. This is a sealed electrohydraulic unit. These are from outboard transum lifts that push/pull 7500 ln/lbs2. I have the gauge that indicates up and down. If you know anything about boats these actuators are very impressive and they are water proof, no hydraulic plumbing to deal with, just connect the hot and ground to the Battery and away you go. I talked to the manufacturer and the gentleman said the actuator was good for 100,000 cycles. I forgot to ask him about max current draw. I think he said to use a 20amp fuse. I can call and ask again to verify.

 

The emergency proceedure is easy with this actuator. The actuator has a preassure relief screw on the front that if turned 90deg, the piston ram is no longer engaged by the fluid allowing it to move very freely. This relief bolt will be replace with a ball valve and the valve can be controlled from the cockpit. Once the emergency proceedure has been started the preassure holding the gear in the up position is realesed and the gear gravity fall into a semi down position a small johnson bar is used to complete the gear extension.

 

So, to answere all your questions Waiter, and figure out how to best incoporate your controller into this design, we will definately have to talk on the phone. it may take me days to type it all out. :rolleyes:

I'll e-mail you with my number.

 

Tony

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Hey Guys,

 

I too am building my own retracts and am very interested in what you are doing and the cylinders you are using. Please keep us posted as to how its going and what works etc. :thumbsup:

Thanks

Tom

"Time flys when your building"

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Is there another wire that connects to the electropump to tell it which way to go (UP or DOWN).

 

This sounds like a simple project and is just a minor modification to my new Infinity Aerospace model LE2

 

Give me a call later this evening, I'm getting my taxes done and probably won't be finished till about 6pm, Then I'll be bummed out the rest of the weekend.

 

four one nine seven eight seven ninty five eighty five

 

Waiter

F16 performance on a Piper Cub budget

LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract

visit: www.iflyez.com

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look at this one as well. these are good for 1 million cycles. why these aren't used in retracts today is beyond me.

 

Mmac can custom make these they are out of canada they ask alot of questions for their use. Make sure you never mention the word "AIRPLANE" say "off road vehicle" or "ROBOT" they run about $2800 to $3000 dollars but well worh it, I think. The one I have is $1800 got it off ebay for (ready for this) $300. the guy had 2 more but I can't remeber for the life of me who it was. I think they pop up from time to time on there, you just have to keep looking.

 

Tom are you an engineer?

if not that's O.K. I support your efforts 110% either way. If you don't allready have it get the book Landing gear design for light aircraft BY: Ladislao Pazmany. I can't say enough about it.

 

Waiter I'll call you later!!! Hey that rhymes

Introducing%20the%20Mini-MAC1[1].pdf

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"Tom are you an engineer?

if not that's O.K. I support your efforts 110% either way. If you don't allready have it get the book Landing gear design for light aircraft BY: Ladislao Pazmany. I can't say enough about it."

 

No, I'm not but I have worked in racing for many years and have welding and fabrication experience from working in drag racing, worked my way to top fuel and also in Nascar for several years.

I am planning on retracts like in the picture with Koni Coil Overs if I can figure out the correct spring rates I need! Hint Hint!

I'll attach a pic if I can

Press on

T

"Time flys when your building"

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Tom

 

Are you planning on using an oleo strut? That really complicates the design.(not to mention weight) not to say you can't do that but the math to work that out is pretty intense.

I chose to go with a set of Grove aluminum gear. Robie Grove can figure out the gear spring rates for all types of aircraft using flat spring type legs. The legs are made from 7075 1"in thick aluminum really nice stuff very lite weight 11lbs each.

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I was planning on using the Koni coil overs like they use in race cars. Spring and gas shock are combined and are adjustable with the spring as well as extra mounting holes in the legs themselves. In the pic above, I wont use the wheel fairing. Do you have a contact for the ones you speak of?

Press on!

Tom

"Time flys when your building"

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