Sig Kadet LT-25 build.
 

I have been wanting to build this kit for some time but it seemed like that everytime I had the money, I couldn't find one. Well, I got one now and am grinnin ear to ear. :D

Power will be an O.S. F3-30S that I had sitting around for ages. And at this point I'm not sure what mods Ill be doing except for dual aileron servos and a bolt down wing untill I take inventory and look it over. So far all I have done is open the box. I'm considering building it as a flat wing and may add a 1/4" tri-stock to all the leading edges of the control surfaces insted of sanding the leading edges for more control but at this point, I'm not sure that will gain me much as far as control goes versus the additional weight involved.

I'm a tad worried I may end up with little power to spare with the little 4 stroke so I may be looking for ways to lighten her up.

Welp, time to take inventory and strap some waxpaper down.

RE: Sig Kadet LT-25 build.
 

<span style="font-size: large"><span style="font-family: Comic Sans MS">I LOVE THIS PLANE!!!!!</span></span><span style="font-family: Comic Sans MS"><span style="font-size: medium"> <font size="3">this is the plane i learned (i guess still learning) to fly with. it's powered with an o.s. .32 2-stroke, and flies like a dream. almost over powered to the point i'm afraid to get too crazy with it.i got it from a guy out at the field after i folded the wings back on my other trainer. it was already built, but i haven't done anything to it except a pull-pull tail wheel and the bolt on wing thing. i'm curious to see how the build goes, so definitely keep it coming. i'm getting anxious to recover mine, as it's beginning to peel loose from the time put into flying it and not such a good job covering it from the other guy. mine's almost hard to put on the ground; it floats sooo much.</font></span></span></p>

RE: Sig Kadet LT-25 build.
 

Hi Gary, You've selected a good airplane for a project. Especially now that Sig may have discontinued kit manufacturing. I enjoyed mine until a mid-air destroyed it. Want 1/2 a wing and complete tail section?? ........Anyway you might enjoy these two threads out of the past: (click on):


http://www.rcuniverse.com/forum/m_25...tm.htm#3620312

http://www.rcuniverse.com/forum/m_52...tm.htm#5214279

RE: Sig Kadet LT-25 build.
 

Discontinued kit manufacturing?

RE: Sig Kadet LT-25 build.
 

<span style="font-family: Comic Sans MS"><span style="font-size: x-small">did someone say discontinued??? say it ain't so!!!! not that i like them alot, but i like their planes.</span></span>

RE: Sig Kadet LT-25 build.
 

Suggest you call Sig about reducing the wing dihedral. I contacted Sig when I was going to add ailerons, for my Sig Senior kit plane and they suggested a new dihedral angle. You might also ask them about engine size recommendation.

RE: Sig Kadet LT-25 build.
 

IIRC, someone bashed the LT-25 into a sport plane a couple of years ago and posted a pic here. Again, IIRC it had no dihedral, the tail plane lines were changed, stringers were added to the fuselage to round it some, a cowl was added and a turtle deck, simulated open cockpit and windscreen... it looked very nice and the owner claimed it flew great.

As to power, if the OS four stroke .30 is similar in power to the Saito .30 you will be fine. I've one with a Saito .30 and it flies great.

RE: Sig Kadet LT-25 build.
 

Thats good to know, thanks.

Well I'm running exteemly slow on this build since I am working 7 days a week right now but I did manage to allready mess up. lol

Seems I left out the sheer webs and glued the indoard first 3 ribs in. Luckily it was just a matter of improvision. :)

RE: Sig Kadet LT-25 build.
 

<span style="font-size: small"><span style="font-family: Comic Sans MS">do the shear webs go under the ribs or something? did you read the other 2 threads about this plane? i thought they were kind of short. kind of disappointing. i was hoping for more.http://www.rcuniverse.com/forum/js/f...n/rolleyes.gif


edited is the entire kit laser cut? </span></span>

RE: Sig Kadet LT-25 build.
 

Probably the main reason I started this thread Crash. Theres just not much info on this plane and hopefully we can get more folks interested in it. Especially those guys who have gone full circle from a trainer to the low wing spincter pucklers who miss those high winged planes and lazy days at the field.
As far as the sheer web mistake I left the notch part to the right and cut the web at the next notch flat. I would of taken a pic of what I did but I was a little embarrased in what I did.

Oh well. Thats the thing about kit building. Your gonna make mistakes esecially when you get a little cocky with yourself and DON'T read the instructions! [8D]

Yes, all the flat sheets are lazer cut and done perfectly. However, and I'm being really picky! The left wing LE is kinda wacky and doesn't fit into the notches very well. I guess it's milled. But in order to keep the LE straight and inline with with the top mainspar, I had to leave some gappage. I guess I could of tightened it up and did more sanding as some guys would do, but I'm of the school who hates sanding and would rather add a little glue to fill gaps.

Ill take some pics of that after I pull the panel off the board.

RE: Sig Kadet LT-25 build.
 

I wouldnt be asking this if I would of thought ahead and pre-drilled the ribs for the dual airelon servo set up. So for grins I pulled out the kit prebent wires for the single servo set up and weighed them. And they came in at 14 grams. I figger by the time I add the required epoxy etc, I may end up at 20 grams.

And then I weighed an addtional servo, two servo leads and a Y harness and they came in at 68 grams. I figger by the time I make and mount two servo lite ply trays and the mounting blocks, I may end up at over 100 grams. Roughly 2.8 ounces heavier than the standard single servo set up.

No brainer?

Edit: Forgot the pics.

RE: Sig Kadet LT-25 build.
 

<span style="font-family: Comic Sans MS"><span style="font-size: x-small">i really don't think it needs the extra servo. i have just the one in mine and i can still do a barrel roll, up high enough. and it doesn't really need a quicker roll rate. you could mechanically adjust the control horns for mor throw advantage if you wanted it to roll a little quicker. but like you said, lighter weight, less time and lazy sunday flying. 3 perfectly good reasons. i'm a fan of the dual servos for my own reasons. mainly, i don't like the thought of needing to remove or repair a control surface with something glued or epoxied into it. dual servos, i pop the linkage off, cut the hinges and BAM!!!, it's off.

the bolt wing thing is easy. i just took part of the wing trailing egde off there in the center and gluedin a piece of balsa to trim to size and epoxied a 1/8 inch piece of ply over the area for reinforcement. then on the inside of the fuse, i epoxied little blocks and drilled and tapped for the 1/4 x 20 nylon bolts. very simple. i haven't paid too much attention to any other ways of doing it, but let me know if you have a different way that may be better.</span></span>

RE: Sig Kadet LT-25 build.
 

I'm glad you mentioned the bolt down wing because I got lost in the building frenzy today and probably would of had both wing panels built with the inboard sheeting done without thought of how Ill be doing the bolt down wing design. After looking again, I would rather go with a twin dowel set up in the front than rather trying to drill down the center of the leading edge at W1.

Ill probably go about an inch from the center of each side for the dowels and add an etxra support block for the aft end of the dowels so they don't rely on the LE only for support.

RE: Sig Kadet LT-25 build.
 

As far as the rear bolt down goes, I think Ill pull off finishing the wings and move onto the building the fuse so I can better see how much room I have to deal with and if I might run into any clearance issues with the airleron torque rods.

RE: Sig Kadet LT-25 build.
 

And, I made another boo-boo. I messed up on the sheeting. lol

It's all good though. A little filler goes a long ways. :)

RE: Sig Kadet LT-25 build.
 

Message directly from Sig: http://www.rcuniverse.com/forum/fb.asp?m=9905840

RE: Sig Kadet LT-25 build.
 

<span style="font-family: Comic Sans MS"><span style="font-size: x-small">i was kind of curious about some of the planes i've been seeing on e-bay. not that that's perhaps where they're coming from, but they look alot alike with the 4* series. not sure why people can't keep to themselves, instead of ruining it for those that actually spend the time to design and build things. but i don't know what is going on really. it just sounds like crap to me. i am glad to see that they are pressing on with the kits and such. i really like their planes. yours is coming along really well too. sorry i forgot to mention about the leading edge of the wing part. i shaped a 1/2 x 1/2 balsa and glued it to the leading edge area inside the fuse and a 1/4 piece of ply to either side of the very inbd ribs to anchor the dowels into. slip the exposed through the holes in the balsa piece, sit the bottom down and shoot the nylon bolts in. for the bolt down part inside the fuse, i just used small size blocks epoxied to the fuse sides, to keep from interfering with the aileron linkages in the fuse. i feel alot better that way than rubber bands. they got changed every time, but when i needed new ones, it was a trip to staples or a week waiting for a box from towerhobbies. nobody likes to be grounded for not havingrubberbands. http://www.rcuniverse.com/forum/js/f...bout_smile.gif</span></span>

RE: Sig Kadet LT-25 build.
 

I bet your OS FS-30 does a really good job of powering your LT-25. I used an OS FS-20 on a 42" span model that Global used to sell, it was the Caprice 15 ARF. Other than having a butt-ugly color scheme on the cheap shelf paper covering, it was a wonderful flying combo for just tooling around. I wish I could find another of those models unassembled.


Ed Cregger

RE: Sig Kadet LT-25 build.
 

I'm fixin to put the plane back on the bench. I got side tracked with my newest toy.

RE: Sig Kadet LT-25 build.
 

<span style="font-family: Comic Sans MS">i know what you mean with getting caught up in stuff. happens to me every monday through friday. i hate it!!! so where do you "mountain" bike in texas? up north? i was raised down around Killeen/Copperas Cove. pretty flat, from what i remember. where's the plane? WE WANT PLANE, WE WANT PLANE... are you going to keep it a tail dragger? it's soooo fun.</span>

RE: Sig Kadet LT-25 build.
 

Monday through Saturday and some Sunday's for me right now. I got a little more done on the plane and will post up some new pics tomorrow after my ride. I ride a trail called the anthills in west Houston. The trails are pretty flat but have a mix of technical and easy stuff. A lot of roots on the lowers.

http://www.youtube.com/watch?v=mrVQX...eature=related

RE: Sig Kadet LT-25 build.
 

Now I know why there aint many build threads on this kit. There's just nothing to talk about! It seems to fall together all in it's own. lol
I was just about to the point of joining the wing halves when I realized I haven't figured out how I was going to design the bolt down wing mod. At this point I decided not to join wing halves and not sheet the underside since I will be going with two dowels instead of one down the center.

So I jumped forward to the fuse and a few minutes here and there and it's ready for the hatch and pushrods. Besides a little sanding, I bet the fuse went together in less than two hours.

For the doublers I used Titebond 2 instead of CA as I wanted as much time as possible for proper positioning and I used it sparingly avoiding the edges to keep the weight down and additional sanding . After they dried I went around the cut outs and edges with medium CA. That seemed to work pretty well.

Next steps will be to install the hatch, test fit the tank and Ill be using Sullivan Gold-N-Rods instead of the supplied push rods, not that there is anything wrong with the stock ones, I already had them sitting around. Then back to joining the wing halves and this point, I have zero dihedral. I got a little sanding to do, I want at least a little dihedral.

The OS FS .30 looks pretty good sitting up front and as light as this kit is turning out, I'm sure it'll be fine! :)

As far as covering goes, I have 3 rolls of transparent yellow monokote sitting around and in order to save a few bucks, Ill use some on the underside on the wing so I don't have to buy 3 rolls. My plan is to cover the top and bottom of the fuse in regular yellow monokote and the sides in dark teal. The leading edge of the wing up to main spar in dark teal and the rest in yellow. Might add some accents using the windex method...

RE: Sig Kadet LT-25 build.
 

Files too big. Ill be resize them.

RE: Sig Kadet LT-25 build.
 

Most sites allow 800 on the longest side. I forgot. [X(]

RE: Sig Kadet LT-25 build.
 

<span style="font-family: Comic Sans MS">for the wing mounting, if you haven't already figured something out, you could use something like this on the aft part of the wing. it will keep clear of your aileron linkages, should you decide to use the single servo method. i used the basic same idea, only mine is utilizing little 1" blocks, instead of these. they would, of course, be mounted to the sides of the fuse and all you would have to do is drill the holes in the trailing edge of the wing to insert the bolts through. then cut off the eccess of the bolts so they wouldn't stick way down in the fuse. i agree with the twin dowel on the leading edge, also. i have an RV-4 as well, and on the leading edge of the wing is just a tab that inserts into the fuse a little. should be good enough, but why not have the added insurance.

http://www3.towerhobbies.com/cgi-bin...LXE099&amp;P=0</span>