Sig Kadet Senior - Tail dragger conversion?
 

Hey guys,

I am rebuilding an old Kadet Senior that was originally tricycle gear. I want to convert it to a tail dragger. How did you guys do it? Run a rod straight down from the rudder through the fuselage?

RE: Sig Kadet Senior - Tail dragger conversion?
 

Hey Tom - another project? ;)

I converted an ARF to a tail dragger. I used a second control rod from the rudder servo to the tail wheel assembly. A ply plate was added to the inside of the fuse, on the bottom. A couple of 2-56 blind nuts were added before gluing to the inside of the fuse. I think that I used a Sullivan tail wheel assembly - so the blind nuts were located accordingly.

An LT-40 uses the same fin/rudder stab/elevator approach as the Senior. This was a bit more involved as I fabricated a new fin. There was a reason - stab/elevator had been broken (hanger rash) so I was removing the fin anyhow. The trailing edge of the fin was extended thru the bottom of the fuse. I think that it was 5/16 x 1/2 stock. I cut a hinge slot in the post to accept a nylon torque bearing (like a one side of a nylon Dubro pinned hinge). This was prefect for a 4-40 wire. I was doing a new rudder so I added a block at the bottom of the rudder to accept about 1" of the 4-40 rod. A 90 degree downward bend, thru the torque bearing and thru the fuse bottom. A couple of bends and the axle for a 1" wheel was formed. Oh yea, I soldered a piece of 1/8" brass tubing to the 4-40 wire, slightly flared on the top. It was positioned so that the flare and torque bearing were snug. Did this so that the tubing flare will carry the weight of the rear of the plane - NOT the 4-40 wire sticking into the rudder. Works great.

Obviously, the Sullivan TW with a 2nd control rod was a whole lot simpler and didn't require much work at all.

I'll see if I have some pics of the easy approach.

OK- I lied - not a Sullivan TW(used that for my Senior kit built as a tail dragger). Memory typically fails me - they all look the same. http://www.rcuniverse.com/forum/js/f...n/drowning.gif The pics show using a hardwood spine used to mount the TW (not a ply plate with blind nuts). This was my first ever trainer and my first ever modification - so sue me http://www.rcuniverse.com/forum/js/f...bananahead.gif

Also, the control rod was a pull-pull deal running thru a couple of plastic tube "guides".

If I were to do it again - what I originally said - not what I really did ...

RE: Sig Kadet Senior - Tail dragger conversion?
 

Thanks Seamus for the in depth reply! :)

This is a new project, but an old airframe I have had for years. The impetus to get going on it is because I want to have a "test mule" for testing out those 2.4 radio receivers before I install them in a 'good' plane. :eek:

RE: Sig Kadet Senior - Tail dragger conversion?
 

I bought one used that is set up as a tail dragger. It has a rod running through the fuse to steer the rear wheel.

RE: Sig Kadet Senior - Tail dragger conversion?
 

That sounds like a simple way to do it Jeff, thanks. :)

RE: Sig Kadet Senior - Tail dragger conversion?
 

<span style="font-family: Comic Sans MS">i have a kadet MKII that i converted to a taildragger and ran a golden rod to the rudder and pull-pull cables from the same servo to the tail wheel, exiting out the bottom through the same 2 tubes that seamusg has on the bottom of his plane. the cables are connected to the outer most holes on the servo head, while the rod to the rudder is installed on the one just inboard of that. i like rigging cables though. either way is great.</span>

RE: Sig Kadet Senior - Tail dragger conversion?
 

This is what I did, not high tech, but it worked fine, and was easy.

RE: Sig Kadet Senior - Tail dragger conversion?
 

Iunearthed the pics of the LT-40 approach.

Iused a threaded 4-40 rod and inserted the threaded bit into the rudder to make sure that the 30-min epoxy had something to bite on.

The rudder &amp;fin are both built up and sheeted. I was practicing to improve my technique before I jump on my GPExtra 300S build. Finally got everything straitht after 3 attempts. Not saying I'm slow - but jeez - I used too much Titebond and it really warped the end product (yea - Iused weights for days).

RE: Sig Kadet Senior - Tail dragger conversion?
 

These are all creative, and brilliant I might add, solutions! :)

Thank you all! :D

RE: Sig Kadet Senior - Tail dragger conversion?
 

Not hard to do.

I drilled a hole up through the fuse bottom and made sure it came out right at the fin/rudder joint. Then I epoxied a bit of brass tube from an old ink cartridge in.

I got some control rod wire and did a 90 degree bend about 3/8" long in one end. I cut out a piece of the rudder a bit over 3/8" long and about 1/8" deep right at the edge.

I slid the wire in and epoxied it into the slot, reinforcing with a but of nylon mesh.

Next step was to put 2 rubber servo grommets with brass inserts onto the wire with flange ends facing outside. Put a wheel collar over that. Go down about a quarter inch below the collar and bend the wire back 45 degrees. Then bend 90 degree to the side, allowing enough to mount the wheels and collars. Finally, press the wheel collar lightly against the lower grommet and tighten the screw.

Did this on my Kadet Sr. and it has worked for over a decade.

Tom

RE: Sig Kadet Senior - Tail dragger conversion?
 

Just a CG note. For every 1/4 oz. added at the tail you'll need to offset this with 1 oz. at the firewall.

RE: Sig Kadet Senior - Tail dragger conversion?
 

Good note seamus, but also keep in mind the main gear will be removed from behind CG &amp; relocated a few inches ahead of CG. Should compensate for added tailwheel &amp; loss of nosewheel.

KMOT- you'll want to mount main gear so it's centered directly under (or close within reason) the leading edge of wing w/ plane level.


-Rep

RE: Sig Kadet Senior - Tail dragger conversion?
 

Rep - center of the main gear axle (?) on the leading edge?

You didn't fly off carriers in the early 70's did ya?

RE: Sig Kadet Senior - Tail dragger conversion?
 

There are a ton of taildragger conversion threads on RCU, I think you willl find that LE or slightly forward is the general consensus. Works well on mine.

RE: Sig Kadet Senior - Tail dragger conversion?
 

Works well and the LE bulkhead is right there to tie into to take the loads.

RE: Sig Kadet Senior - Tail dragger conversion?
 

Yep mines the same set up and has a 91 four stroke it is GREAT. Tail dragger the way to go.

RE: Sig Kadet Senior - Tail dragger conversion?
 

I converted my Kadet Sr. ARF to a taildragger usng a pull pull set up on the tail wheel. I set up the rudder on the same servo attaching the pull pull to the outside of the servo arm and the rudder in two wholes. This gives me more responsive ground control. I am running a Saito .91 4 stroke and loving it.

Grump Gorilla

RE: Sig Kadet Senior - Tail dragger conversion?
 

Grump: Your KS looks awesome!! :D

I have two Klett tailwheels in my stockpile. A 40 to 60 size and a 1/4 scale size. The KS is a big plane. What size tailwheel should I go with?

BTW, I recently noticed that Dubro is now making the Klett tailwheels and selling them in three sizes.

RE: Sig Kadet Senior - Tail dragger conversion?
 

My Kadet Senior weighs the same as my LT-40 - both tail draggers. I'd go with the 40 size unless the plane has been substantially overbuilt.

RE: Sig Kadet Senior - Tail dragger conversion?
 

I wasn't really thinking about weight, although I probably should have. I was thinking more of what would look right on this big 'ol airplane. :)

RE: Sig Kadet Senior - Tail dragger conversion?
 

A couple of pics on my KSARFtail dragger - pull-pull operated too

RE: Sig Kadet Senior - Tail dragger conversion?
 

Here's where I am at with the rebuild. I waited weeks to get my covering material from Hobby King. Came last week and I got started on the job. I stopped so I could get a couple of boats ready for a regatta this weekend. I will start back on the covering next week and probably get the tailwheel framework started.

RE: Sig Kadet Senior - Tail dragger conversion?
 

Sorry for the delayed response, and by the way I saw your pics later added. VERY NICE! Hope to see the completer project. Am out of town presently and do not recall the size of the tailwheel. I will check when I get home next week.
The attached pics may help. Note that on the servo I used a larger arm so that thewheel connectionwould not interfere with the pull pull on the rudder. After observing my own pics I see that I did just the opposite of what I said earlier in the thread. I attached the pull pull on theOUTSIDE of the arm instead of inside as I previously indicated.
Let us see how your Kadet turns out! What are you planning for power?

RE: Sig Kadet Senior - Tail dragger conversion?
 

Based on Seamus' and your pictures Grumpy, I see that the 40 size will be plenty adequate and look good as well.

I am uncertain what I will use to power it but I am thinking of going with the Sig recommended power of a .40 sized engine. I have a few I can choose from in my collection.

RE: Sig Kadet Senior - Tail dragger conversion?
 

I would recommend going on the high side of the Sig recommendations re power. I used a .61 Evolution before my conversion. I find the higher power can be very beneficial in certain situations to get out of trouble.