Bill Diedrich

The fuselage is from the old rubber band LT-40 ARF cost $29.99
tail feathers 4 pcs @ $1.99 (fin, rudder, stab & elevator), wing kit
$44.99, plans sheets $10.99, built the wings in a weekend, did mods
to fuselage & covered wings in 3 evenings, 1 evening for the radio install
and off to fly.........quite an enjoyable project, going to do another for
my oldest grandson (13) before the spring.

SeamusG

Bill - you got some serious speed skills. Must use CA.

What 'cha mean "do another for my grandson"? Sounds like a joint-build project to me  - unless, of course, he doesn't live nearby.

SeamusG

I've changed the scope of this project - it is now LT-40 Redux ...

New scope:
Tail Dragger (no change here)
Bolt on Wing (no change here)
Replace the Covering (my original covering was junk - though it looked good at distance - it needs to be reshrunk frequently - and it weighs a ton)
Convert single aileron servo to dual aileron servos - replace the iron wood aileron wood - replace CAhinges with Robart hinge points
Replace the rudder - it got dinged up during covering removal.
Upgrade tank from 10 oz to 14 oz.
Bill Diedrich's LT-52 with wheel pants looks GR8!Just may add wheel pants - imitation is the ultimate complement

To Date:

[*]The cat has been skinned and paint that tenaciously held on to the covering has been removed with acetone.[*]Holes (wing mount dowels, firewall nose gear holes, main gear holes) have been filled with FR putty (finishing resing &micro-balloons).[*]Thin wing sheeting that was originally sanded to the point of finger pressure bouncy has been removed.[*]The single aileron mount has been removed, ailerons and torque rods have been tossed, torque rod trenches have been filled with wood &covered.[*]Ribs now have aileron servo wire holes.[*]3/16" ply plate with 1/4" x 3/4" x 1"maple blocks have been assembled into a new LGplate and installed in front of F-2.[/list]Things that I have learned: Using aliphatic resin to create fillets where ribs join sheeting is strong - really strong. And the ARis rubbery. A heat gun will really toast this stuff. A little will reactivate the glue. A lot will burn the stuff.

pic 1/5 - various sets of holes have been filled. They will get touched up when the wing saddle is refit with FR putty.
pic 6/7 - the LGplate of 3/16" ply with 4 maple blocks located at the corners. Tri-stock will not be needed as the bblocks are flush with the sides and F-2
pic 8/9 - 30 min epoxy used to both glue it in place and fuel-proof everything.

Oh yea, once the LGplate with blocks glued and I inserted it into the fuse bottom - it wasn't coming back out for pictures.

SeamusG

The previously used landing gear has been refitted and a new 14 oz. tank has been fitted.

This is the first time that I've used a 3/16" ply base with maple blocks for mounting the main landing gear forgoing the use of blind nuts. It feels better. Just don't know how well or poorly it will work with smaller diameter bolts like 6-32 or even 4-40. Any comments on NOTusing blind nuts for smaller bolts?

pic 1 - love those RTL hex bolts - 100 unit count.
pic 2/3 - plenty of room for 14 oz. Still an inch or so available for a longer length tank. Gonna have to get a 2500 mAh battery pack.
pic 4/5 - LGin place. axle tips are within .1 mm of each other (yea right - but so close). I like the back side without blind nuts.

SeamusG

A couple of things have been completed.

New stab and elevator were constructed of "lighter" wood
New fin and rudder were constructed of "lighter"wood
New ailerons were constructed of "lighter"wood
Payback? 2.6 oz. were dropped in the tail feathers. 1.5 oz. were dropped from the ailerons

The total weight of the tail gear, tail wheel, wood backing plate, blind nuts and collars - .7 oz.

I'm hoping that the 2 oz. reduction at the tail should allow the engine to be relocated 3/4" back - to where it should be located per the plans.

pic 1/4 - the tail gear (yea, needs a bit more caster) - lite ply was used between the gear and the fuse to increase the stand off from the fuse and lite ply with 1/8"balsa side support (tri-stock not available that small).
pic 5 - new fin & rudder
pic 6 - new elevator, stab and ailerons.

Btw - SIGis the sole source for the 5/16" stock used in construction of the fin & stab. My LHS had a big selection. There was quite a bit that was like stone. Acouple of sticks that almost broke under their own weight. Luckily I found enough 5/16" x 5/16" and 5/16"x 1/2" stock that was straight and firm (not rock hard).

Daren71

One thing I just noticed. Are you going to have enough prop clearance? I fly off of a nicely groomed grass runway, and I did have green prop tips. Hope it all works out. Daren

SeamusG

Good thought. I'm using the same main landing with the tail wheel as I did when it had a nose wheel. Prop clearance wiil not be an issue.

Bill Diedrich

I am currently designing a unique LT-40 project at the moment,
I'll share it with you guys in the next week or two, just got to get
it a little further on before I show ya'll the pics, you'll like what it
is when you see where I'm going with it.

Bill D.

SeamusG

Aw Bill - that ain't fair!
We want pics now!
We want pics now!
We want pics now!
We want pics now!
We want pics now!
We want pics now!
We want pics now!

Now, that's being a bit redundant on my part but what the heck ...

Bill Diedrich

Patience my freind, this one will blow your mind....

Live Wire

Then people wonder why we have HIGH BLOOD Presure

SeamusG

(Re)construction is nearly done. The tail feathers have been glued up. The tail surfaces have been set up for the hinge points. The wing's root rib joint has been re-fiberglassed. I'm using 2" wide glass and finishing resin for one coat. The weave will then be filled with filler.

SeamusG

As my son would say "DUDE!" ...

Hey, I'm still waiting for Iron Eagle to finish his Somethin' Extra that has "somethin' extra" - a bunch of composites and aero mods.

I'm NOT holding my breath.

SeamusG

Time to finish of the fuse &wing. To do yet includes fitting new ailerons. I'll probably put a bunch of blocks together to add to the trailing edges of the stab, rudder and wing where the Robart hinge points extend into the voids.

pic 1 - new pile of finishing resin putty - 1st time using Z-pozy - a bit different but not much
pic 2/3 - the fiberglass tape was 1st laid down with straight finishing resin then sanded. here the putty is filling the weave
pic 4 - putty around the stab and fin - just a small softening fillet
pic 5 - oops - knocked the top off of a rib tip
pic 6 - square the original rig with a hardwood 1/8" x 1/2" sanding block (120 / 220 grit)
pic 7 - scribe the shape on scrap 3/32" balsa from adjacent rib
pic 8 - rough cut repair piece
pic 9/10 - repair fitted and CA'd
pic 11 - tape to protect the adjacent ribs from 12" sanding block
pic 12 - final shaped rib repair

SeamusG

The ailerons are shaped and drilled for hinge points. The trailing edges (TE) are all preped for hinge points. Where the TE is narrow an additional balsa block has been shaped, drilled and CA'd to the TE. Where ever there is a space that will be confined by covering and there is NO natural access to atmospheric pressure a hole has been drilled and reinforced with CAto ensure that the heating of the covering will not simply balloon the covering. Just have to remember to run a hot pin thru the holes on the various TE.

pic 1/2 - the wings and ailerons are ready to go.
pic 3 - just waiting for the finishing resin putty to dry then it will be sanded to shape.

Just need to fabricate the wing dual aileron servo supports. Noticed that the hatch covers from a 4Star60 are a perfect fit. And Ihappen to have a spare set of 4Star60 hatch covers. Em, maybe easier than Ithought.

Bill Diedrich

Just finished off the drawing mods for the secret little project I call my ****-******** LT-**
I'll give ya a hint, 2 fins & 2 rudders. Now don't ya go loose no sleep tryin' ta figure it
out now.

Bill D.

SeamusG

2 engines?

Bill Diedrich

Your on the right track.............82" wing span

Bill D.

SeamusG

There are two warbirds that really get my attention - P38 & B25. Looking forward to your "contribution".

Bill Diedrich

Not going to look like a P-38 or a B25.

You are probably to young to remember the guy back in the late 50's early 60's that took two J-3 Cubs
and made a twin out of them, well that is where this project is headed, ordered the other fuselage, fin &
rudder this morning from Sig along with another Avistar 46 to go with the one I already have. Will start
the wing and stab mods this coming weekend if it ever warms up enough to work out in the shop.

Bill D.

SeamusG

That the Wagner Twin Cub? Gotta admit that it's one unique project. How close will the rear most engine's prop tip be from the "front" engine?

Just wondering - which fuse had the controls? Be cool to put the mother-in-law in the "other" fuse.

SeamusG

Are you planning on 2 throttle servo channels or using a "Y"? Well, I guess that this question applies to both throttle and rudder. Dual tail wheels? Em, I can really see how a project like this could take shape.

I'm thinking that the LT-40 platform could be molded into a Ford Tri-Motor. The wing is just wickedly stout as it is. Tossin' a couple of nacelles on the wing would be doable. Ok, I'll be quiet now.

Bill Diedrich

I have been thinking of a LT-40 bashed into a twin for some time
did some scribling sketches as something resembling a Britten-Norman
Islander with nacelles on the wings to a resembalance of an OV-10
Bronco, P-61 and a few others, but something like the Wagner Twin
Cub kept zeroing in on my thoughts.

SeamusG the props will not overlap, engines will be 12" on center,
swinging 11-7 props. Each fuselage will have it's complement of
servo's "Y-d" to the reciever, even thought about twin Rx's, don't
know if that would work well on PPM/PCM or not. Will "Y" the engines unless
my 6 channel Futuba EXP will let me mix Flaps & Throttle channels, which
I don't think it will.

I'll keep you informed and post pics as I go, might even do a thread on
twins section.

Bill D.

SeamusG

I wish that I had a clue. I was in the Civil Air Patrol in the early 60's but the enthusiasm never stuck. Now I'm grateful for the internet.

Just a note on the Rx - I've heard that using 2 different channels to control (mix) like components (ailerons, elevator halves, multiple throttles, etc.) can suffer from a lag between a signal going to the primary channel and the "mixed" signal going to a 2nd channel - thus a bit of "out of sync" condition. Just makin' a note - no personal experience. Think that this might be specific  to Spread Spektrum stuff. The solution is to mix "adjacent" channels. This would require plugging prim aileron into aileron, and 2nd aileron into rudder. Gets kinda messy keeping track of what channel is controlling which component.  Hope that this makes some sense ...

Bill Diedrich

Just checked with the club radio expert and was told using 2
Rx's is the way to go on this project, says he can't see any
harm of using seperate Rx's in fact he thinks it is a great safety
feature if one fails. Will save me from running those "Y" connectors
through the wing center section. I will be setting these up on PPM
as I have 2 NIB Futaba Rx's and crystals. Waiting on Sig & Balsa
USA orders arriving, will get started on the outer wing panels in the next
couple of days, getting them done and out of the way so I'll be ready
for the new stab/elevator and wing center section once I have all of the
extra balsa & parts required.

Bill D.