Sig Kadet Senior ARF Modifications - RC Groups
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Nov 07, 2007, 12:03 AM
Flying is a gamble.
N925WB's Avatar

Sig Kadet Senior ARF Modifications

Wow! 450 Views so far! I'm impressed!

Well, I don't have too much to say about anything today. It's the start of another midnight sift, and I have a big day tomorrow. I have a guy coming down from Baltimore to buy my Sig Kadet Senior (pics below), and I'm a little sad about it. I put alot of work into that plane, and even though it's an ARF, I am really proud of the end result. I've seen others converted to tailwheel, but I like mine the best (go figure).

When I first bought the Kadet, I knew I wanted to convert it to a taildragger, but I wasn't exactly sure how I would make the changes. After much searching here on, I found a couple of people who had already done the conversion, and pooled what I thought were the best of all the different ideas.

The landing gear I used is from a Hangar 9 model. I think it is for the older .40-size Cap 232, the grey one with the teeth on the front. It is a nice aluminum gear with the grey matte finish, not polished. The specs for the new gear almost perfectly matched those of the stock main wire gear provided with the ARF kit. I found these at the LHS by accident. I didn't "engineer" the landing gear placement, but I remember reading some books and articles on the subject the gave a degree sweep in front of the center of gravity that seemed to always fall near the wing leading edge. So, I set up the Kadet with the wheel axles falling just behind the wing LE, but far enough ahead of the CG to prevent nose-overs. I have never nosed this plane over on take-off or landing, and I have never ground-looped it. I would say that the LG placement was spot-on!

The wheel pants were another LHS find. I was looking through the bargin bin at Danielle's R/C in Nashville, TN and found a pair of all white spats for the U-Can-Do 3D .60. They were big enough to the fit the Kadet's stock wheels, and looked just "old-school" enough to match the overall styling.

Mounting the main LG wasn't too tough, but I didn't want to just bolt them against the 1/8" balsa fuselage bottom. If I did that, they would eventually crush the wood and become loose on the plane. Yeah... No. So I had to cut a whole in the bottom of my brand-new plane. Fun!!!

I ended up using a piece of 1/8" ply in place of the balsa, and then backed it with a piece of 1/4" ply that overlapped the existing balsa sheeting, which ties it all together. I then used 1/4" balsa triangle stock on all the corners and edges to give it extra strength. In almost three years of flying, I've never had a gear failure.

The tailwheel was a simple installation. I cut a piece of the 1/8" balsa out of the tail and replaced it with 1/8" ply which was then backed with another piece of ply inside the fuse to tie it into the existing balsa. The tailwheel is a Sig unit. I believe it is the .60-size, but I don't remember.

Controlling the tailwheel was another story. To accomplish this task I ran pull-pull cables from the rudder servo arm in the fuselage. In order to pass them through the fuse bottom, I installed a pair of plastic tube guides which I cut flush with the bottom sheeting. This keeps the cables from rubbing on the balsa and still provides for a clean exit. This set-up has worked perfectly.

Other changes I made to the Kadet included mouting the engine inverted. In order to get the prop shaft in the right place, I had to drill new engine mount mounting holes on the firewall and install new blind nuts. This wasn't as bad as you would think, but it wasn't a piece of cake, either. Just remember, measure twice, cut once. In my case I like to measure a billion or so times!

The engine I chosed to use was the Saito .72. I know, I know... "That's too much engine for that plane!" No it's not. I've found it to be the perfect match for the Kadet. It has plenty of poop for climb-outs without being unlimited, and doesn't increase the speed of the plane at all. The Kadet is so draggy I don't think anything could make it faster. More power will just make it climb better. The only problem with the Saito has been on landing. Because it is a fairly large engine, and because the Kadet is such a great floater, any RPM will allow the plane to just float on down the runway. Landing can be a chore because of this, so I switched props to an APC 3D prop (big diameter, low pitch), and my landing woes were cured.

I also installed a remote glow igniter to save my fingers from getting chopped up, and I also used a remote fueler. I had to mount the battery up under the fuel tank due to tail-heavy condition, which would also be a great place to mount an on-board glow-driver. I always wanted to install one, but I never got around to it.

This plane has been the best flying R/C plane I've ever owned. I've taken it with me on four moves, and flown it in three different states. It's not 3D, but it is very fun to fly. With enough effort it can do rolling circles! Just shooting touch-and-go's is a real dream, and practicing one-wheel landings is a blast! I will definitely have another Kadet Senior ARF in the future, but I just don't have a vehicle large enough to transport it in now.

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Nov 07, 2007, 11:39 PM
Blew out my flip flop
David Hogue's Avatar

A 72 too much??? Shoot, mine had a 91 surpass, and the serious Sr Kadet modifiers in our club are running Saito 100's and 125's!!! These are scratch built and FAR from dihedral, huge ailerons and elevators, 3d throws and servos that are up to the task. They will hover, knife edge, about anything else and still slow down and float. About as much fun as you van stand in this hobby. I miss mine
Nov 09, 2007, 06:07 PM
Registered User
TDisaster's Avatar
Nice, I was going to buy one a while ago, maybe I might reconsider now
Latest blog entry: Tracker III Repair Thread
Nov 03, 2010, 11:26 AM
Big Jim

Unbelievable fun

A friend of mine has the blue one with an O.S. .91 two stroke & it is absolutely a blast to fly. He still has the trike gear but I hardly ever use the nose gear. Just goose it, pull up elevator & it's airborne. Drag it in real slow with full up elevator at touch down & roll out maybe a foot & a half. It will hover at less than half throttle & then accelerate straight up at full throttle. I'm an old time RC'er but would love to have one myself. If I ever do get one I'll definitely make it a tail dragger. It really looks good with the white wheel pants. On his, the nose gear is really flimsy since it's jacked up so high to clear the prop.
Mar 03, 2011, 01:58 PM
Registered User
HawkerTyphoon's Avatar
It looks fantastic as a tailwheel airplane. I think it suits the "classic" look much better. not many golden age airplanes had nosewheels anyway. Fantastic job on a fantastic airplane.

Feb 25, 2013, 07:16 PM
Prairie Pounder Aviation

sig kadet

thats a beautiful airplane! can you tell me where you got the aluminum gear? thanks!
Feb 26, 2013, 06:21 AM
Flying is a gamble.
N925WB's Avatar
Originally Posted by peck5989
thats a beautiful airplane! can you tell me where you got the aluminum gear? thanks!
I bought the landing gear at Danielle's R/C in Nashville. I'm not sure if Hangar 9 still sells this gear as a replacement, but I believe it was the stock gear used on their .40-size Cap 232.
Feb 26, 2013, 11:44 PM
Prairie Pounder Aviation


thanks for responding,i'll check it out!
Feb 27, 2013, 04:34 AM
Flying is a gamble.
N925WB's Avatar
Originally Posted by peck5989
thanks for responding,i'll check it out!
You're welcome!

I'm certain that any gear that comes close to the specs I've outlined will work great. If you cannot find the exact gear, I'd suggest going with something taller and maybe fatter from front to back. This would increase your angle of attack on the ground allowing for slower landings, and the extra fat front to back would give more contact surface area between the gear and the fuselage, reducing and tendency for the gear to fold back on landing.

I'm certain you could probably have a set of gear made, or make them yourself. I think it would look really nice with white-painted composite gear.

Good luck!


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