Greetings Adrian, thanks for your help. I have some details that show the main gear actuator, the up lock and down lock, and the gear saddle. What’s missing is a detail showing how this all fits together. I could scan them and e-mail them to you if you think they would help.

Hello Guys,
Just signed up on the site from a suggestion from a rep at: Robart Mfg., have read through this forum and I'm also interested in retracts for the cessna hi wing models, looking thorough the forum have noticed you have not replied about the subject in a while maybe I can spark back up the conversation, I was going down the same road to cessna.com, and I emailed robart to see if there were any custom set available with them or anyone else they knew and they sent me here.
I am purchasing a cessna 182 .40 sized and am also interested in going to the hanger nine 1.20 sized and would really like to see a set and be able to name it with the designation: RG or R182, I see what you guys mean by pricey customs by the one guy on the web you where talking about and wish it could be much more simple and not so expensive, in looking at the forum started on this, the first thing to say from me is that the main retracts have no doors to worry about and robart does sell a pair of gear that not only swings 90 or 100 or 110 degrees but also rotates, I think we could maybe use this app. if the retract would swing about 110 degrees and only rotate 80 degrees, I think that would mock what the actual system does on the real aircraft and would also look realistic, I will let you know about the rotation that is a question I would ask the rep at robart if you can limit the amount of rotation to only 80 degrees instead of it probably rotating 90 degrees, as far as the swing, from the angle of the gear straight down to the approx. position of the gear inside the belly of the fuse. I think that it would probably be about 110 degrees which is one of the model retracts I had seen on robarts web site,
if you get this message, and you have found out anything better by now please let me know, or let me know if you are still interested in figuring this out, and I will let you know what I find as well.
Hope to hear from you soon,
Steve, Naples, FLorida

Greetings Steve, sorry it took me a while to write back. I have moth-balled the Cessna retracts, i'm too frustrated with it to work on them right now. I have tried (with a mock-up) mounting standard retracts at different angles, but I cannot get a scale look, or the wheels to retract completely. The only thing I can think of, is someone is going to have to figure out a way to replicate Cessna's mechanism. I tried contacting Cessna for help, and they didn't even have the courtesy to write back. needless to say when I buy a full sized airplane it will not be a Cessna. At this point, I'm not sure that I even want to model one of their airplanes[sm=angry.gif] Robart hasn't been ant help either. I guess they would rather parrot the same boring stuff that every one else does. Any how, good luck on your project, and feel free to share what you come up with.

not to bring a old thread back from the dead, but i think i ran into a sollution that might also help you. i havea GP lancair that i am converting to a lancair IV(winglets/retracts), and the full scale lancair IV has a similar gear system as a cessna RG.

the full scale lancair has a tubular strut like a cessna and retracts into the rear of the fuse because the wings are too thin to accomodate the wheels. on the real deal, the landing gear struts are fixed into a hub that rotates straight back, and uses the angle they sit at and the way the gear struts are bent to fit cleanly into the fuse, and the gear doors are just spring loaded and utilize the gear strut to push them open. i will try to get pictures soon, however i have a friend who has a real lancair IV that he built, and i will have acess to all the drawings/ blueprints. let me know if anyone is interested.

I'm Interested!

It's pathetic that the people at Robart know about the thread, know about the interest in the retracts, yet can't pull their heads out of their [X(] and produce a set. Century Jets now makes a set for the 337, but they are not scale, so the gear would not end up where it’s supposed to be. But at least they tried.

here is a pic of the spring loaded gear doors that are pushed open by the strut, and a pic of the hub where the strut is fixed.
[img][/img]
[img][/img]
[[img][/img]

looks like im not doing something right posting these pics because you cant englarge them...

Look in lower left of response box (Click here to upload images)

Click there and upload the pics instead of linking them from image shack

Don

[]

I'll have to take some pics at work, I maintain 3 cessna RG's a P210 a regular 210 and a 172RG Cutlass (Gutless) LOL The mechanism is so simple it is ingenious but hard to explain. it is a simple swing and the angle of the pivot makes it work similar to the Grumman wing fold. I'll see what I can do. Also check out the cessna owners association for pic's/info. the actuators run from front to rear with a separate hydraulic up and down lock which locks each leg into each seat when extended or retracted.

I think a number of us would like to see the full-size mechanism!

David

If some one could provide a picture of the parts, and a video of them in action, a set could be drawn in CAD, and then sent to a machine shop. I have a link somewhere to an online machine shop, where you draw the part in CAD, send it to them, and for a fee, they CNC machine it. I haven't worked with them yet, because I haven't had anything to send them.

well right now, im trying to get my hands on the plans ect. tomorrow i should be drawing them in soldworks, and sometime this week, cutting them on the cnc mill. they should turn out great. how much are some of you willing to pay for a ready to install unit? i cringe at some of the prices people have been quoted. as soon as i have more info ill post it

this should look better

http://www.youtube.com/watch?v=j4azT3MWtHE

Look's to me much like an F-16 style gear retraction only reversed and without the rotation of the wheels. I would think that standard retracts with the proper gear struts and mounted correctly could be made to work.

The first three pics show how the gear retracts on my CBM F-16. Unless I'm missing something, it look's like a set of bent tube struts adapted to a setup like on the F-16 while maybe not totally scale would be darn close.

The last pic is a Lancair with what I believe are a set of Gene Barton retracts....very similar also.

swatace23

And these should be a little easier on the eyes.

swatace23,

Here you go...a couple more pics of the Lancair gear. This is the Hostetler Lancair.

thanks again, and not to be a pain but the more pics the merrier!
what mechanics are those, and do they cycle more than 90 degrees?
thats a beautiful plane btw, is it yours?

I fly an 172RG and I have the POH. It only shows a decent side view. That will show the landing gear in the down position and where the cutouts are for the wheels when the gear comes up. I have watched the gear come up (retract) from the ground as an RG took off. I have never seen it let down except for the last second or so from the cockpit. My view is blocked. I own a Mooney and I have never seen the gear move as it's hidden from view.

I can describe the gear retraction on the Cessna RG. The legs release and fall almost straight down and slightly back with the wheels almost touching. After a pause they begin to get pulled aft and up into the gear well which is in the fuselage. Upon initial release they do sway with the wind until they are pulled up into the well.

I think it is a two part deal. The lega are on a pivot bar. The legs spread and lock to come down and gravity lets them fall together and down to retract. All the while, the pivot bar that holds the hinged legs rotates to pull the gear back and up or the reverse to go down and forward.

So, for a model, maybe a big pivit bar (like an elevator linkage) would rotate the gear legs back (up) or forward (down). Then you could either spread the gear (down) or pull them together (up) with something. Sounds complicated. But the legs could also just run in a track that did the leg alignment while the pivot bar rotated.

On second thought you might only need the pivot bar. A lock in the gear down position gets released upon retraction, gravity does the work. Wind keeps them pulled backwards and thus wheels together. The pivot bar rotates it all up. The reverse would be the pivot bar rotating the gear forward. Gravity would cause them to spread as the pivot bar (axle) rotated forward naturally spreading the legs into the up locks.

There you go... have fun.

Hi, is there any chance you (or any one else who owns a RG Cessna) could post some pictures? I have some drawings in the service manual I bought, but nothing that shows how everything fits together.
Thanks,
Pat

i fly a cessna 337 every weekend if someone would like pics or video of it let me know, but the video is gonna be of it cycling in the air.

Hi, you are one lucky person, the 337 is my favorite airplane. I was always going to buy one when I got my license, but then I ran out of money. Pictures would be very much appreciated. I think that will help with retracts for all of the high-wing Cessna's. I also plan to plans-build a 337 once I finish some of my other projects. How is your gear for the lanceair comming?

Hi all,

I've flown all the Cessna RG singles as well as the 337 and the gear is not as complicated as you all imagine. Yes, it is cleverly designed and is kind of unusual in its looks, but it all gets back to positioning of the gear mounts and the angles involved during retraction. When the pilot selects gear up, the lever he moves in the cockpit simply releases hydraulic pressure that has been holding the gear in the locked position. It then freefalls due to gravity and "dangles" until the hydraulic pump builds pressure on the other side of the actuator and moves the gear back and up into the wells. Hydraulic pressure is then trapped and holds the gear up. Extension is simply the reverse procedure. I've had situations where there was a leak in the system and the gear has sagged out of the fuselage until the hydraulic pump has cut in and reestablished pressure. Most light aircraft are like this and have no uplocks as such.

Years ago, I build a Pilot kit of the F16 and although I eventually sold it unfinished, I had installed standard 90 degree mechanical retracts in it and they worked just fine. Although in that situation, the gear legs were straight, whereas the Cessna ones are bent just near the wheel, there should be no real problem getting it all to work. The secret is to just play with the geometry until they retract into the wells and then bend the axles to suit the extended position.

I will note that the 337 gear goes further (ie rotates more than 90 degrees) but the principle is the same. Just try and steer away from the older Cessna 210 as it had doors and you don't need that complication. Cessna found that themselves of course and deleted them from later models as they only improved the speed by a few knots but added a bunch of maintenance woes. The 337 gear of course always had doors so if you're building one of those you'll be unable to avoid them... good luck.

I have the service manual for the 210, and it shows the doors. Some day I hope to build a 210 as well, and I'd probably put the doors on it for the cool factor. It certainly looks doable with a sequencer.