my05monte

I'm wanting to know how to go about converting my sig kadet lt40 into a taildragger. I found posts on bracing the vertical fin and plan on doing that. It's the arf version and I haven't started putting it together yet. So now's the time to do these changes.

w8ye

My Feedback: (16)

My ARF is about 10 years old and is the old style with the rubber band wings. I have since converted the wing to bolt on much like the new ARF.

Main gear
Look in the radio compartment. In front of the servo tray and behind F-2 there is a squarish area. Cut a piece of 1/4" birch plywood this size and epoxy on the floor. Add 3/8" triangle at the ends against the fuselage doublers. Use a 60 size aluminum gear
http://www3.towerhobbies.com/cgi-bin...?&I=LXJ924&P=7
This is the one I used . . . http://www.horizonhobby.com/Products...?ProdID=HAN160
and using holes in the gear, drill - tap four 1/4-20 holes down through the fuselage directly into the plywood. Put thin CA on these threads to reinforce the threads. When dry - retap. Mount the gear using Dubro 1/4-20 nylon wing mounting bolts.

Tail Wheel
On the tail locate the rudder vertical hinge line and extend this down through the center of the fuselage bottom. Epoxy a piece of brass or aluminum tube just large enough to clear 1/16" music wire up through this area as a support for your tail wheel wire. This tube will be along the elevator pushrod so pass it on the side of least resistance. The top is anchored in the solid balsa of the elevator and the bottom is anchored into a plywood reinforcement epoxied onto the bottom of the fuselage. Watch your weight back here. Use a Dubro 40 size tail wheel bracket.
http://www3.towerhobbies.com/cgi-bin...?&I=LXD850&P=7
and make a longer new 1/16" or .062" music wire piece for the tail wheel using the wire that came with the bracket as a pattern. This new wire extends up through the tubing in the fuselage and turns at a right angle into the rudder in the area of the control horn. The right angle must be bent after the wire is inserted through the fuselage. Drill the rudder for the wire and prepare the rudder and vertical fin for the CA hinges and CA Glue. Use epoxy around the tail wheel wire where it inserts into the rudder. Use the piece of plywood to reinforce the area of the bracket to mount the bracket with the screws provided.

I used 3 1/2" Dave Brown main wheels and a 1" Dubro tail wheel. I used hex socket head screws for axles on the main wheels.

The front of the landing gear is at the leading edge of the wing.
The battery and radio are up under the fuel tank. I moved the receiver antenna out the top of the fuselage so it would be away from the main gear.
It looks like it came from Sig as a tail dragger.

w8ye

My Feedback: (16)

For others with a LT40 ARF or Kit already assembled or built.

My LT40 was assembled close to 10 years ago as a nose wheel plane.

You have to cut the rudder off at the hinges.

After mounting the tailwheel assembly and wire with the right angle. Drill the hole in the rudder for the tailwheel wire. Rehinge with new CA hinges. Get the rudder where it will reassemble without glue. Then epoxy the tail wheel wire into the hole and slide onto the hinges. Apply new CA to the hinges.

In making new slots for the hinges, I just cut alongside the original hinges with an Exacto knife.

The other type tailwheel conversions I have seen utilized a new additional control rod from the rudder servo for the tail wheel or utilized a pull-pull system.

I might add that the LT 25 kit plane has a pull-pull set up on the tailwheel and a pushrod to the rudder.

Some people have mounted the main gear in front of F-2 and some have them mounted centered on F-2 but the plane has ample tail weight with the gear legs behind F-2. With the gear too far forward the taildragger will be hard to land unless you full stall land it. The closer to the CG the easier they land up to the point where the nose wants to tip over. A compromise has to be reached.

The typical position for the main gear is at the leading edge of the wing.

The plane should still balance as shown in the instructions or plans. That would be in the area of the main wing spar.

w8ye

My Feedback: (16)

Flew my LT 40 tail dragger again to day and just shot touch and go's.

I've flown my LT40 a lot this spring. I converted the wing hold down over to dowels in the front and Dubro nylon bolts in the rear.

The plane flies great and is a joy to land. I can full stall land, 3pt, it or land the main wheels first and let the tail settle down. It is very easy to do either way. When the wind is gusty I land it main wheels first.

The OS 52 seems just perfect for it but a Saito 50 or 56 would be great also.

PipeMajor

My Feedback: (1)

I guess I'm puzzled why everyone wants to convert the LT-40 into a taildragger. You can buy the LT-25 and get a taildragger right out of the box.

My LT-40 is still serving dutifully in a trike gear configuration. The ONLY major mod I made to the kit after it's first year of training was to replace the wire main gear with a composite dural type main gear. The stock gear on the LT-40 is a bit soft and surprisingly short. I power mine with a ball bearing .46 engine and an 11-5 prop. If I ever went off our surfaced runway into the grass... the LT-40 makes a rather effective lawnmower.

My favorite maneuver with the trike geared LT-40 is to taxi out, line up with the runway, apply full up elevator and gradually increase the throttle. It will rotate then lift off at a very slow speed. At that point I ease off the elevator but keep adding throttle.

The LT-40 is also a load of fun with skiis on a fresh snow cover.

w8ye

My Feedback: (16)

It just as easy to take off as taildragger

I fly from grass and it doesn't mow any.

I also have a LT25 and they are almost as big as a LT40 but very light weight and not as good in the wind as the LT40