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Old Apr 24, 2012, 09:49 AM
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Hobbico Twinstar bash to Lockheed Electra

Hi everyone,
I have a new Twinstar I'm doing some kitbashing on. I always thought the Twinstar had a faint look like a Lockheed Electra. I don't want to make mine look like an Electra (or I'd just build one) but I thought it would be cool to do some mods that would pay tribute to it.
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Last edited by hasselblad7; Apr 24, 2012 at 07:27 PM.
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Old Apr 24, 2012, 07:27 PM
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One thing I've been thinking about is i'm a bit surprised that the ailerons are so narrow yet on all the videos I've watched the roll rate looks pretty good. While I've got the covering off I'm tempted to make the aileron strips a larger percentage of the cord but I'm unsure it would make a difference. Any suggestions or thoughts on it or perhaps flaps or flaperons etc?

On a similar note I see alot of builders are putting the batteries in the nacelles vs the fues. Since I have the airframe stripped I can go either way. Again any suggestions?
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Old Apr 24, 2012, 08:31 PM
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I'm sure I will do a lot of small things but I'm hoping to limit it to three main mods: give it a duel tail, make it a tail dragger, and make the rear fues taper up instead of taper down.

I wanted to get the taper change out of the way first. I decided in order to stay true to the original design instead of rebuilding a lot from scratch, I would just flip the rear upside-down. The original has a gentle curve downwards I'd like to preserve but just use it in the opposite direction.

I cut the back of the fuse off in an arch both to give me a better regluing surface, but also to allow me to make fine angle adjustments by sliding it on the arch.
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Old May 02, 2012, 01:07 AM
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Tail (keep it simple?)

For the tail I was tempted to keep it ultra simple and just add flat plates to the ends of the stock one and remove rudder control altogether.

Once I decided to add rudder control I initially thought the simplest would be to use two small servos for each fin. I initially laminated the stock elevator with 3/32 balsa to give it more thickness to accommodate the embedded servos and to add stiffness to hold their weight and the weight of the fins. (photo 1)

In order to remove some of the weight in prep for the weight I was going to add, I shortened the cord of the elevator (photo 2). This was also based on the right or wrong assumption that the stock elevator was designed over-sized to keep trainer like behavior. The narrower cord also allows me to give the vertical fins a broader rudder

I after starting in that direction I concluded it will be fairly complicated and heavy (in the wrong spot) for all the servo mountings and wire dealing so I decided to use aileron rods imbedded for rudder control instead (photo 3). I still feel like there are better solutions but the elevator came out to only 2 oz so good enough for me.
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Last edited by hasselblad7; Jun 16, 2012 at 02:43 AM.
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Old May 06, 2012, 08:03 AM
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I thought that I would let you know that it is looking good. I tend to do a bit of changes to ARTF's myself. Just because it is quicker as I do not have the time to build from scratch. I will folllow to thread to see the final result. Keep up the good work.
Regards
JM
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Old May 14, 2012, 02:24 AM
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I had to postpone and pull some extra hours as work to prep for the mother's day rush.

Before I cut off the rear of the fues I took a ruler and drew a line marking the angle of incidence of the elevator. Now that I flipped the rear upside down I can use the line remark and cut the elevator saddle at the same angle it used to be.
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Old Jun 16, 2012, 02:47 AM
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Photos of the fins under construction
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Old Jun 20, 2012, 08:21 PM
VNE Mach 2
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Keep us updated, this is a really cool project
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Old Jun 25, 2012, 08:14 PM
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Love what your doing to the tail! Keep the info comming!

I am thinking of a twin tail, sorta B-25 style, and making the plane a tail dragger with some simple gear mounted to the fuse, just infront of the wing mount.

Wont have to cut and modify the wing that way..

Bill S>
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Old Jun 28, 2012, 01:28 AM
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Thanks for the comments.
It gets complicated from here. Here is the twin tail trial fit. I have to install a control rod for each rudder, one for the elevator out the back, and one for the tail wheel. I will probably make the elevator bolt on to keep all these linkages accessible. It is going to get tight back there.
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Old Jun 28, 2012, 01:42 AM
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Moving on to the wing in procrastination to the linking up of the tail:

Reviews show the roll rate to be slightly slow so I decided to bite the bullet and make larger surfaces.

Might as well add flaps while I'm at it. I did a 60%/40% flap aileron ratio on a mini pulse last year and the roll rate didn't impress me. As a guess I'm switching it 40%/60% with the aileron taking up the lager portion this time. Reports on the Eflite Pawnee claim the tiny flaps those make a difference so we'll see if it works here.
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Old Jun 28, 2012, 08:08 AM
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How did you come with the dimensions for the new vertical tails?

Also, you might want to see if you can mix the flaps/ailerons together to increase the roll rates...

Wow, built up ailerons! I was going to cheat and use larger aileron stock....

Looks GREAT!

Bill S.
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Old Jun 28, 2012, 11:50 AM
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The original fin is not super big so to make the two end fins each half the area of the original would have looked too small and very strange. The ones I cut were done mostly from what looked right within reason. Mine came out about 50% more combined area than the original.

What I put more importance on was the ratio of the stab area to the rudder area. The original has a very small rudder (trainer style) which I imagine limit the aerobatics of the original.

Its not that I'm trying to create a 3D ship or anything. Its just with all the work that goes into these rebuilds, I want to ensure it will take a while before it bores me.
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Old Jun 28, 2012, 12:04 PM
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How about fabbing up another set of vertical fins/ruder while your at it and send them to me? lol

Did you leave the horizontal stab stock and mount the fins to it or did that get a new build as well?

Bill S.
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Old Jun 29, 2012, 02:01 AM
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The verticals are easy. I cheated and used the balsa sheet as a plan/building surface. pm me your email and I will xerox the paper template I used for the fins.

The horizontal I used the stock but if you look at the earlier post I shortened the cord. Now that it is coming together I wish I shortened the span an inch or two. Most full scale ships have their horizontal span similar to the width of the outside of both the engine nacelles. The stock one is a few inches wider so mine may look very slightly out of proportion. But it should be fine.
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