nightflyer01

Hi, I am trying to design a set of retracts for Cessna aircraft such as the 172, 182, 210 or the 337. However, all I have to go off of right now is some pictures of the retract sequence viewed from the outside. Does anyone have any drawings that would show how these work? If not, any idea of where t look? I tried writing to Cessna, but they never replied.
Thanks
Pat

TexasAirBoss

My Feedback: (22)

Years ago, one of the Magazines had a scratch build Cessna article with home made retracts. I think it was a C210 or C177. It was way cool how they did it. It was most likely RC Modeller, I think that is what I got back then. You might check their plans or call them.

CoosBayLumber

My Feedback: (1)

You are describing the type of L.G. which folds up under the belly of the fuselage, correct?

There was one of the jet manufacturers who was marketing the model gear a good 3-4 years ago for a Vought Corsair, or Crusader. They had it available separately. Can't remember if it was Century Jets, Jet Hangar or who, but saw it at Pasadena show.

'course then if used you would then have to design the whole model around the only available size.


Wm.

nightflyer01

Thank you for your replies. I have seen an article in Model Airplane News, where someone built retracts for his high-wing trainer, but the geometry is wrong for the Cessna. I will look through RC Modeler, and see what they have. I will also check some of the jet manufacturer websites and see what I can find, however I imagine that they will be expensive. There is a company that makes a 337, and the retracts to go with it, but the retracts are 500.00. I have been told that the service manual has some detailed drawings, but I haven't been able to locate one.

grbaker

My Feedback: (29)

I think Ramon Torres is the guy that kits the Cessna 337 kit. His retracts are the only ones I have ever seen for a Cessna. The Cessna retracts are very unique in geometry and it is unlikely you will find any jet retracts that are similar.

nightflyer01

I looked at the landing gear for the jets, and while they are close, they aren't quite right. Also, with what they cost, I could get the ones made by Ramon. I also searched the plans on RCM and MAN, but didn't find anything. I guess I'll have to keep looking for the service manual.

Idigbo

Pat, I was looking on I think Century Jets site just the other day, they listed and showed a pic of Cessna retracts, might show you something.

Ian.

nightflyer01

The retracts on the Century Jets web site is for the 310, which is a low wing model.

Idigbo

Sure there is some on there for a high winger retract model, where the mains swing rearwards to lie in the fuselage, they the ones?

nightflyer01

Yes, but I could not find them on the site.

beenie

My Feedback: (9)

The somewhat complicated looking retract sequence of the high wing Cessnas is accomplished with a simple pivot. I don't have any pics right now, but I will look for some.

nightflyer01

Thank you for the reply. Some pictures of the Cessna would be cool. I have also purchased a service manual (off eBay), so when that gets here it should help too.

beenie

My Feedback: (9)

I didn't find any pictures that would be usefull to you, just a front quarter shot of the airplane. The mx manual should be helpful, but I don't remember how many useful drawings that it would have. I used to fly the Cutlass RG, and have often thought about modeling it. The main gear retract has always been the hangup. I don't have access to any tools to build the mains. My other option is to make a smaller model and just leave the gear off, but that is no fun.
I have included an embarrasingly rough scetch of what I remember of the system. The mains are actuated by a hydraulic cylinder with a rack and pinion. THe pinion is on the gear trunion, and I think that it is on the inboard side, not outboard as I have drawn. It may take a little experimenting to get the angles right, as there are a few that have to work together. I hope that the drawing helps.
Ben

nightflyer01

Thank you for the sketch. I am hoping to come up with something that I could send out to a CNC machine shop, yet still have it affordable to the average Modeler.

nightflyer01

Well, I just received the service manual that I bought off eBay, and it doesn't really show anything. What a waste.

rongreg13

My Feedback: (129)

I've also struggled with the issue of locating scale retracts for the Cessna RG lineup. The retracts by Ramon Torres at www.rtaerospace.com are the only ones I've found that actually retract in the scale method. Sure, you can get a set of F-104 or similar retracts that just retract back at an angle from Robart or CJM, but to get the spindly, curved struts that drop down and then back like the full scale planes I don't think you'll find any out there other than the ones that RT has custom built.

nightflyer01

I have seen the setup on the Rt Aerospace web site, and wile it's nice, it's way out of budget, and much bigger then what I need. I was hoping to develop something in the .40 size or smaller. I would of thought that with as many people as I've found that want them, some one would make them by now (other then Rt).

beenie

My Feedback: (9)

I am not surprised that the mx manual didn't show anything. You may have omre luck with a parts catalog for the plane. However, the parts catalog may not show the relationships of the different assemplies. Those manuals are written for repair, not design. It has caused me a great amount of fustration looking through them for modeling intrests.
Ben

nightflyer01

Dang, I wish I'd known that before I bought it. I guess I could try to get a parts catalog, but I'm kind of reluctant to spend more money now that I've essentially thrown away what I paid for the manual.

hattend

My Feedback: (20)

I have thought of a scale retraction for high wing Cessnas ever since I got my Royal Skymaster and TF 182 although the 182 is already built as a fixed gear version.. I even drew up numerous sets of drawings that I figured would work but I have no experience with a lathe or mill to make the pieces.

You need a two part action with the first part dropping the gear out of lock and then pulling them aft into the fuselage., Then you need the opposite action to occur to unfold...ie: the wheels drop down staight and then they spread and lock. There are some sequencing air valves sold that allow this to occur. One set raises the gear and then closes the gear door and then opens the gear door and drops the gear. This would be what is needed for the Cessna gear to work.

You build a set of u-shaped metal tangs to which the gear are suspended to so they hang down with gravity. You then have an air cylinder that, when extended, pushes the inside ends of the gear legs down and a cam goes over center to lock the gear down and out. Mount the tangs/gear/air cylinder to a milled gear block that is bottom pivoted which goes from straight up and down to zero degrees forward when pushed by another air cylinder.

When you flip the retract switch, the tang mounted cylinder unlock the over center lock and pulls the gear ends up which allows the LG to fold down. Then, the air sequence valve activates the second cylinder that pulls the gears up into the fuse. Switch back, the second cylinder drops the legs straight down and then the tang cylinder forces the gear to spread out and the cam lock ensures the gear won't fold on a hard landing (you don't want just air pressure holding the gear spread out.)

Anyway, hard to desribe, I have the idea in my head, I have drawn and redrawn the gear numerous times but toss them as unbuildable by me.

So, anyway, that's my idea...run with it...LOL!!!

Don

nightflyer01

Thank you for the reply. One of the ideas I came up with, used a spring to make sure the gear dropped down, and a cable to pull it back up. I have also looked at micro air cylinders, which could be used along with a sequencing valve to do the same. My problem is how to mount the gear so it looks scale, and is able to drop down then rotate as it pivots back. Do you have any sketches you could share?
Thanks

hattend

My Feedback: (20)

I'll have to re-draw them. I'll post them later.

Don

nightflyer01

Thanks.

hattend

My Feedback: (20)

Here's are some quick and dirty sketches I just did at work

Don

Adrian

Goodday nightflyer01,
I have read your question about retractabel landing gear for a 337 Cessna. I am also building a 337, and also wanted a retractabel landing gear.
In Switserland a guy is also trying to build this gear with piano stings and a winch, but it doesn't lookes solid enough.
The problem that you will have to face, is that the rotation of the main landing gear is greater than 180 degrees, and a standaard servo or pneumatic cilinder won't do the job.
Mechanical I have build up de rotation of the main landing, from the parts out of the box, and it works. Now I'm building the pneumatic cilinders in to drive the rotation.
I have found a pneumatic cilinder that hase a rotation of 190 degrees, and is not to heavy or to big (match box size)
When I have more information for you I, will send it to you. (I am sorry for my poor Englisch, my homeland is The Netherlands)