LT40 Build thread
 

Last year I built a four star 60 and I enjoyed the build. I didn't get hardly any flying in last year, and I misjudged and put my trainer into a treetop. I wanted to build another airplane so I decided to build Sig LT40 and make it a taildragger. I'll post pics as I go along, so maybe it will help someone else. Also I got a lot of help when I built my last airplane. The first thing I did was open the box and get the manual out, then start checking everything off. Putting the wing parts in the lid, and putting the fuse parts back in the box.

RE: LT40 Build thread
 

The pics didn't go in the first post, I'll have to figure this out again.

RE: LT40 Build thread
 

you've got patience...i dig in and get the glue....:D

RE: LT40 Build thread
 

I found the spars and the doublers. I glued them up before putting the plans down. After putting the plans down and covering them with waxed paper, I pinned down the spars, then trial fit all the ribs first before gluing.

RE: LT40 Build thread
 

As I glued the ribs in I made sure they were straight up and down. The yellow tool there is handy it is square on the bottom, and you can use it for degrees. I used it to bevel the ailerons on my four star. Sorry I didn't post more pics as I was going on step by step, I just got in a bit of a hurry. The first rib is on a bit of an angle and the template has a bit of a curve on it. so I used the tool with the degrees to recheck. I put it on the drawing in the book as a reference.

RE: LT40 Build thread
 

I'll post the rest of the pics, the second wing goes the same as the first one. I did one wing one day, and another one today. On the 3rd pic I found an abs pipe joiner. It works good for making sure the ribs are straight up and down.

RE: LT40 Build thread
 

looks good!!!!![8D]

i did my four star 120s one wing in a day too....once i get going............................................. ..................:)

RE: LT40 Build thread
 

Geeze, have you get enough clamps??? :D

RE: LT40 Build thread
 

Harbor Freight baby.!!!! I have the same set.
They all come in one box.....for like $4.99

.....and the large ones are STRONG.!!!

RE: LT40 Build thread
 

Tail Dragger This was a 10 yr old ARF I converted
http://image2-6.rcuniverse.com/e1/ga.../lg-123518.jpg
The tail wheel wire goes up into the rudder through a guide tube
http://image2-6.rcuniverse.com/e1/ga.../lg-123516.jpg
use Nylon bolts to hold the gear on. There's a 1/4" plywood plate on the inside with the threads tapped directly into the wood reinforced with CA
http://image2-6.rcuniverse.com/e1/ga.../lg-123521.jpg
This is the main gear I used
http://www.horizonhobby.com/Products...?ProdID=HAN160
This is the tail wheel assembly I used but I made a new wire to go up into the rudder
http://www3.towerhobbies.com/cgi-bin...&I=LXD850&P=ML

RE: LT40 Build thread
 

I cut off the spars on the wing tips and in the 1st rib then sanded them. Then cut out the die cut part in the first rib. Minnflyer is seem you never have enough clamps. Is that ever a nice looking Lt40 W8ye. It looks really nice as a taildragger. I have a rounded fiberglass gear for the front. Did you cut a v in the bottom of the rudder? That is what i'm planning to do.

RE: LT40 Build thread
 

Next I installed the dihederal gage on the end of the wing. I did a trial fit before gluing it all together. Then I cut out the slots for the dihedral parts. In Canada we have a Princess auto, and I found some little files or different shapes and small tools that come in handy.

RE: LT40 Build thread
 

Finally the wing assembley glued. I used epoxy to glue the wings together.

RE: LT40 Build thread
 

One can never have enough clamps..

You know that Mike... Geesh... [sm=biggrin.gif]

RE: LT40 Build thread
 

A suggestion.. If I may...

Consider using individual servos on the ailerons. It's not totally necessary.. but nice to have.

I did it on mine. And it's not to late to do on your wing.

I thought I had posted pictures how I did it.. But I can't find the thread... I can post some pictures if you want....

RE: LT40 Build thread
 

We Love our LT40, what a great first model... We have a OS46 on it and there is NOTHING sluggish about our trainer, except maybe my thumbs:D

RE: LT40 Build thread
 

For my tail dragger conversion the tailwheel is controlled by the rudder

I made a new longer tail wheel wire for the tail wheel bracket that is longer on the top to extend up into the rudder hinge line where I drilled 1/16" hole in the rudder and with a 90 degree bend, inserted the tail wheel wire into the hole in the rudder with epoxy all around it.

I used a tube guide for the tail wheel-rudder wire that is in line with the rudder hinge center line. It is anchored at the top by the wood of the horizontal stabilizer and at the bottom by the extra piece of plywood that was epoxied onto the bottom of the fuselage.

RE: LT40 Build thread
 

LT 40's are cool........[sm=shades_smile.gif]

RE: LT40 Build thread
 

very nice! Ive built the LT 25 which is very similar. they go together nice without too much sanding/fitting. You just cant beat a kadet for a nice easy flying plane, thats quick to build and finish.

RE: LT40 Build thread
 

Thanks. Best trainer out there, IMO.

RE: LT40 Build thread
 

vmsguy I think i'll keep it simple and just go with one servo on the ailerons. I know what you mean though I have 2 on the fourstar 60. I finished the sheeting on the wings. Cut the slots out of the trailing edge pieces for the aileron torque rods. I used CA to hold them in place being careful to get it only on the outer casing of the wire. I glued the pieces on the wing with epoxy. The CA is giving me a cold flu like feeling. I think i'll use epoxy and alphetic glue for the rest. There was a little piece missing on the one piece so I made a piece and glued it in. I'll sand it off later when it dries.

RE: LT40 Build thread
 

If you are going for a bolt on wing now is the time to be putting your dowels in the front and the plywood in the rear for the bolts

RE: LT40 Build thread
 

w8ye, I think I'll just use the elastics instead of the bolt on wing. By the time you posted, I already had the sheeting on, and if I was going to do that it would be better with a block behind the leading edge. Anyways, I missed taking some pics again. I cut the hinge slots out. I'm using the dubro nylon hinges. I have a slotting guide and a tool for cutting slots. On the bevel of the ailerons I had to do them without the guide. I cut the hole and slot for the aileron torque rods. Then taped the ailerons and used a piece of balsa with pins in to hole them secure along with a couple clamps while cutting the aileron ends.

RE: LT40 Build thread
 

You are doing a good job

RE: LT40 Build thread
 

Thanks w8ye. I cut out the area for the wing servo and glued the plate on. Then glued the 2 stiffeners on the top of the wing.

RE: LT40 Build thread
 

Looking good!:) Your 'bout done with the toughest part. The fuse is gravy.

RE: LT40 Build thread
 

Here is a picture of my son's LT40. It was built as a taildragger and has a servo in each wing. We used a Saito 56 on the front.

RE: LT40 Build thread
 

That LT40 looks like a winner.

I've found the Saito 50, 56, & 62 engines to be easier to adjust than the OS 52 Surpass.

RE: LT40 Build thread
 

That LT40 looks great Rvator. Thanks Mrbigg. I glued the fibreglass strip with epoxy thinned with alcohol. Then I glued the servo plate on with epoxy also. I'll be using epoxy on the fuse. I just hate the ca glue. I marked the lines and put the motormounts on the firewall. I turned the blind nuts backwards to hold the motormounts while I fitted the engine. Then turned them around one by one pulling them into the plywood. It says to drill the engine holes and gives you a measurement. I'll leave that till last. The weight and balance will be different since it's going to be a taildragger. I also glued the blind nuts on the back of the firewall. I put some tape over the holes so I wouldn't get any glue in the holes.

RE: LT40 Build thread
 

I finished putting the stiffeners on the sides. I used a couple of drill bits in the holes where the dowels go to make sure they lined up.

RE: LT40 Build thread
 

I finished the fuselage. I used epoxy in the first 2 formers. Then as much as I hate it, I used ca on the rest on the sides and bottoms, just to keep everything tight together. Then I used alpetic glue for the top piece. I put some weight on the front too keep the bottom tight.

RE: LT40 Build thread
 

I made up a plate to put inside to support the landing gear. I used epoxy and tightened it all down installing the landing gear temporarily. I put the gussets in for the firewall.

RE: LT40 Build thread
 

I fuel proofed that area where the fuel tank goes. I thinned down epoxy with some alcohol. The part the tank sits on is pretty flimsy and it only sits on a small shelf at each end so I glued a couple stiffeners on it and that will make it more solid on the sides. I glued the windshield in and the piece that the wing sits over ahead of the 3rd former.

RE: LT40 Build thread
 

I just finished up the horizontal stabilizer, and the vertical fin.

RE: LT40 Build thread
 

I cut the slots for the hinges. I put some filler near the spars then sanded the wings. Also did a sanding on the fuselage. I'll do a bit more sanding before I cover.

RE: LT40 Build thread
 

I installed the pushrods, and put extra support in. There seemed to be a lot of sag. On the servo tray I glued some wood supports so the screws would hold better. I sanded the stabilizer the other day and didn't post the pics, also the horizontal fin. I bent a tail wheel bracket, it was duplicated from the sig fourstar. i put a sullivan tailwheel on it. I'll put a tube through the fuselage and the horizontal stabilizer then bend it at right angle to fit the rudder onto it.

RE: LT40 Build thread
 

You are doing good work

RE: LT40 Build thread
 

Thanks w8ye. I haven't posted lately, I have some more pics. I put some strips on the servo tray to give the screws more to bite into. Finished the fuel tank. Then put the servos in the tray. I started to put a tailwheel with a wire up through the bottom, then I thought i would bend a right angle after to go into rudder, but it's so hard to bend, and I have to go between the hinge and the control horn, so I put in another push rod, crossed it over and will run it off the other side of the servo. I didn't get a pic of that. I finished the covering the horizontal stab.

RE: LT40 Build thread
 

I managed to bend my 1/16" tail wire 90 degrees OK with two pairs of pliers. I had to think about that for a little bit before I did it. Wasn't too hard

RE: LT40 Build thread
 

w8ye, I bent the tailwheel bottom, and it was pretty hard, but it was ok. But I thought, if I slipped bending it for the rudder, over top of the elevator, I could do damage. So i went the other route. I finished covering now, used 3 rolls of ultracote. I will also post a pic of my four star 60, the one I did last year. The wings are in the background. I like the Sig kits.