GAP-RCU

... and some might ask why I spent all that time putting a nice fabric finish on "just a trainer" ... (post 42)

Because we all do what's fun to us!

Gary

FrancisPerson

A fabric finish sounds cool, I'm still not sure about ruining a perfectly good tail dragger. Just flew my Sig 4*40 tonight. Boy do I love that plane!

shd3920

I have heard so much about the Sig 4*40 (all good) that when I start looking for a low-wing airplane soon that will be on the top of my list, or maybe the 4*60 or even the 4*120 if I wanna go all-out. Its about time I get a low-wing plane to add to my hangar.

buzzard bait

Francis, what are you using for power in the 4 Star? Jim

ekir

My Feedback: (1)

I am thinking about building the Kadet LT-25. I have another project that I will be using an OS 52 4-stroke. Do you feel this engine would work well in the Kadet or do you feel it is to much motor? I was planning to use a OS LA-40 2 stroke in the Kadet, but if I can get double use out of the 52 4-stroke, I would like to go that way.

Ed

shd3920

The 52 will be way too much power for an LT-25, I would go with the L.A-40, even that will be ALOT of power but you may get away with that. I am using a .32 in mine.

buzzard bait

Actually, that 32 is more powerful than the 40 LA, and probably not much shy of the 52 four stroke, but the 52 is heavier than either engine. Having seen one with a plain bearing .25, the 40 will be plenty, and the LA is pretty light.

Ed, is the issue that you haven't bought the 40 and you're hoping to avoid an extra purchase? Because switching engines between planes is a nuisance, and I would much rather the extra engine and have two planes ready to fly.

Jim

FrancisPerson

I managed to buy an ENYA .45CX NIB from a friend, and what a great engine it is. It starts, idles very slow > 1900 RPM and it never quits..

AA5BY

I recently completed and have flown an LT-25 powered by a very old Enya .29 sleeved bearing engine having considerably less power than a modern .25 and the Enya pulls the plane very well. I can't imagine needing more power unless the dihedral is greatly reduced and the plane set up for sport flying and then I'd consider a modern .32.... no more.

The most important engine consideration in my opinion depends slightly on if the plane will be flown in an area having little wind. Without some headwind, the plane is a floater and the idle must be very low to get the plane to come down.... so an area with light winds requires a motor that will idle well.

mmmexico

So....tigerdude...how's your build coming??? You sounded a little discouraged about the apparent lack of interest in your build...well..I like it. I decided to build another trainer type of plane and so I got the same kit...mainly because i had a Pitts style muffler and a new engine that i wanted to put in something. So far I've built the bare bones of the fuselage and the wing...this morning I've been working on the hold-down blocks for the wing nuts on the trailing edge of the wings...I also put a dowl through the leading edge and reinforced the mount for the central dowl...in other words I'm getting rid of the rubberbands...pictures to follow.
A couple of days ago I made up some new plywood dihedral reinforcements for the center of the wing...I really needed to reduce the dihedral, and this seemed like a good opportunity to reinforce the center of the wing..It seems a little lightly built to me...again, pictures to follow.
One more note...this kit is a real pleasure to build...it is incredibly simple and easy to put together, and the parts are beautiful...I wish this much thought and engineering would/could go into more scale kits...it's a shame about Skyshark...their kits were beautiful and it was intoxicating to work on them..
See you guys...

Mike

shd3920

Unfortunately the build was never completed. The framework is complete but not fully assembled. I have financial issues right now and I am trying to sell the partially-built LT-25 as well as some of my other planes.

mmmexico

Well...I guess if tigerdude is out of the game, I'll pick up the build where he left off. This is an expensive hobby...no getting around it..I hope that tigerdude makes a comeback and completes his build.
So far, I have done what several guys have done...I took out some dihedral..and used that opportunity to add additional ply supports in the center of the wing...I think that one just is not enough...at least not the way I fly.

The shots below also show the mounting brackets that I put in the fuselage to allow the wing to be mounted with plastic bolts instead of the rubberbands. The trailing edge of the wing, around the mounting bolts was built up solid, and then I put a ply plate on the top to spread the load.

There is a shot of the engine installation...it has a Pitts muffler..which made it too wide to fit within the sides of the front of the fuselage...so I had to take the right side out...but I will cover the top of the engine which will give it a cleaner look.

buzzard bait

Mex--What engine have you got in there?

TD - I hope you can hang on to this plane. It's hard to get your money's worth out of a partially built plane, and some day you might be really glad to have it. I hope the financial picture improves for you soon.

Jim

Hobbsy

My Feedback: (102)

Francis, I changed my mind about the nose gear and the power plant, it now wears a Saito .30.

mmmexico

The engine for this plane is a Thunder Tiger .25 two stroke. I got the engine just because I bought a Pitts Muffler for my OS...but apparently the muffler that I bought was for a different OS .25...mine's pretty old. So, I had a muffler and I needed an engine to go with it...I found out that this muffler also fit the Thunder Tiger...so I got one.
In case you are wondering why I didn't just return it...I can not easily do that. I live in Mexico and so returning stuff is expensive...time consuming and in general not worth the effort.
No pictures today...the internet is running slowly, and I'm having more fun building than taking pictures.

PipeMajor

My Feedback: (1)

Tigerdude - bummer about your situation. I had problems a few years ago (layoff) but appears to be sorted out now so I get to play with my toy airplanes again. BTW, I went to the Sig Mfg C/L contest last weekend. What an absolute BLAST!!!

I'm still flying my [link=http://www.rcuniverse.com/forum/m_3477988/tm.htm]yellow LT-40[/link] I posted here a year and a half ago. If fact, just took it out the other day after sitting downstairs since last summer. I had swapped out the kit-provided musicwire LG for a taller composite dural type gear. Gives me about 1½" additional prop clearance.

Had one very good flight then the hatch cover flew off and is somewhere out in the cornfield now. Making a new hatch out of lite ply and hope to fly again tomorrow for the holiday.

I've always liked the LT-25 and thought of building one myself but we're putting an UltraStick 40 ARF together. With corn planted all around our field now it's getting tougher to make those long straight approaches to land these floaters.

buzzard bait

A TT .25 -- of course. It looked like an OS air bleed, but had the swept back needle.

A friend had one with the same engine--amazingly good power for such a large plane. I like your 90 mount with the Pitts muffler. I think you'll be very happy with your set-up.

Jim

mmmexico

You know...this is a big plane...below is a shot of the wing on my CG Chipmunk..which is a little underpowered with a Magnum .70 four stroke. I hope that all of the people that have suggested that a .25 two stroke is plenty powerful are right.
I have done some work on the tail feathers. Both the fin and the horizontal stab look unnecessarily ugly and cut off. I know that this must be to make the plane easier to cover for people with little building experience, but it does look like someone got after the plane with a chain saw. Below are shots of the tail feathers with my very easy changes...I've added a little weight to the rear of the plane..and I've lost a little of the stab area...but it was worth it.
Finally I have a shot of the wing which is just about ready to be covered. You can see the mounts for the screws on the trailing edge which hold the wing down...they are not as artistic as I wanted, but I was having trouble getting the screws properly recessed..
The next up-date will probably have the radio installed....See you then...

AA5BY

The sacrifice of elevator area will be of no serious consequence as the elevator is quite responsive.

I've a very old Enya .29 sleeve bearing motor, which I'm sure is less powerful than modern .25s and it pulls the LT-25 no problem. Sig emphasis a .25 is plenty of power... why is there such a reluctance to trust a very long and established company such as Sig?

mmmexico

First a couple of non-aircraft related up-dates....our internet connection is running again...always an adventure here in Mexico...and our house guests have departedso...back to work
I feel a little like a Chinese worker in an ARF factory...covering is a little bit tedious. Attached are some pictures of the tail feathers. Nothing special..the numbers are just trim material, and the red and white rudder is the result of covering the rudder with white oracover and then using some red trim sheet to make the stripes...easy and it looks good.
The picture of the servos shows another deviation from the plans. The tiller bar which operates the tail wheel is designed..on the plans..to be operated by a piece of whire that goes from the rudder servo to the tiller bar. The "attachment" at the tiller bar is the problem. The plans direct that this wire come up from underneath the tiller bar..but no attachment system is provided. It appears that the designer thought that it would simply stay in place by friction...or some other magical device. When I hooked it up as suggested in the plans two things happened...first of all, at full right rudder the wire fouled the servo and limited travel in that direction...when I tried it again, the wire fell out and locked the rudder in a full right position...good luck landing it in that configuration.
I could have worked out a system for more securely attaching the wire...and I could have rebent the wire to a more useful shape...but why bother. It was literally easier to build a new linkage out of ball links and 2-56 wire. It is much more secure....entirely slop free...and it looks good.
Next update will probably have the wing done...I'm working on covering the ailerons now...see ya...

mmmexico

Time for another update..actually these updates are determined by how fast (or if) my internet connection is running..if its working well..I'm happy to put stuff up.
The wings are covered and ready to go..again I am struck by the size of this plane. I have never seen a plane this size for which a .25 engine was recommended. Below are some shots of the top and bottom of the wings...I did discover that for attaching trim, the solution sold by the monokote people is hard to use. It seizes up right now. IMHO ironing the trim on is MUCH easier. Live and learn.
The servos and receiver are in as well as the fuel tank. There is a lot of room inside the fuselage for your equipment. I put the battery in the recommended location...all the way forward against the firewall. I have had a quick and dirty look at the balance of this plane and it looks pretty close...probably a little weight in the nose...
From the pictures below you can see some changes on the front of the plane. According to the instructions/plans the windshield is to be glued in place. I wanted to make it removeable so I could more easily get to the fuel tank. You can see that it is held in place by three 4-40 screws and blind nuts. The hatch which is supposed to be removeable is attached by four small sheetmetal screws. Both of these pieces will be covered over so that to access this area I will have to cut the covering. I hope to end up with a relatively accessible area and still be clean and neat. We'll see...Next update will probably have a completed fuselage...

mmmexico

This is the last up-date. I finished it up with a few more changes. I substituted larger wheels for the suggested 3" ones. Where I fly it is a little rustic and it is not unknown for me to need to land in the dirt...so I have larger and stronger wheels front and on the tail.

Attached are two photos of the finished product. I did not post a picture of the underside of the wings which has two, broad yellow stripes running from the leading edge to the trailing edge on both sides of the wing. Anything to help me see.

I read the instructions for the TT .25 engine and it was suggested that this engine doesn't need much break-in...so I ran a little less than a tank through it...and today I went to the field to go flying. The control throws were set as per the instructions and resulted in a very midly flying plane almost difficult to turn...but probably much harder to get into trouble.

It taxied very nicely for a tail dragger and I was able to cleanly take off without incident in a 10mph cross wind blowing 90 degrees to the runway..,.for my skill level this was impressive...on most days this would result in the wind getting under a wing and rolling me over. On the other hand I was concentrating very hard so as to not crash my plane in front of the local club members.

After I stopped shaking I noted that it needed a fair amount of down trim on the elevator...but maybe I started off with too much up-trim...anyhow when the flight was over the trim that I had imputed was not much more than a 16th of an inch...by the way, when I balanced the plane it needed weight in the front but my heavy prop nut from Higbey created perfect balance.

The landing was also in a cross wind but I kept it on our fairly narrow strip...all in all a very nice day...one more note... the Pitts style muffler is wonderful...the plane required absolutely no clean-up after the first flight...I'm not building anymore planes that don't incorporate this style of muffler. This is the end of this thread for me...anymore up-dates will be on the crash page.