RE: Double Taco
 

excellent!

What colors are you going with?

RE: Double Taco
 

I have covered but I ain't photo'd it yet, but think "harliquin" .
There is a reason and I will explain.

For the servos as there seems to be enough depth in the wings for standard sized servos so may be I'll just use ball race for the "flappy bits" and a couple of standards for the the throttle.

Enclosed a couple of errors.
First a slight difference with the rudder post [ooopps!]

And the second, oopps cut outs in the wrong place!![X(]

RE: Double Taco
 

As promised the photos of the covering

Why all the different colours?
Most modellers have a scrap box, well, I also have a leftover coverings box, or in my case a large black bin bag. So to be a bit different I used some of the larger leftovers to cover this plane.
Naturally it had to be bright!

RE: Double Taco
 

My buddy, Flaps, would love it. He's the king of using leftovers, both wood, crashed parts and covering.

RE: Double Taco
 

Nearly finished!!!
The first photo shows the engine installation. Which is relatively simple in the case of a profile. However I have since moved them both further forward to help balancing for the C0f G.
Although for a two engined plane I'm still experimenting for the Cof G, initially I shall start just rear of the main spar, which is about the place for the "Taco".
Note the white bath sealant at the wing joint. This is a quick and effective way to seal the joint against fuel penetration.

The second shows the dual rudder set up. I had tried to link the rudders by linking them using traditional horns connected at the hinge line but this failed to give dual movement. [ie both rudders moving in tandem]. With the ball joints and bolts securely glued into the rudders this systems appears to work.

Hopefully the third shows the all metal pushrod assembly has been followed from the "Taco" construction, which is still used successfully by Sig with their Fazor [my first introduction to profiles].
Note I've increased the "rigidity" of the pushrod by use of saddle clamps and tubing.

I'm not sure if it will work but I've glued hardwood bearers directly to the wing skin and mounted the servos directly to the assembly. Where the servo output head passes through the skin I've glued a ply "doughnut ring" to protect the edges. [Not necessary through the plywood hatches].

Whilst I think about it there is room for a flap. But I'll see how it flies first.:eek:

RE: Double Taco
 

That is one cool arse plane!!!

RE: Double Taco
 

Quick update

Although I've finished the build I still have the final report and pictures to post.

However I tried the maiden flight today but failed to get air bourne. This was due to extra long grass and the rudder joining connection rod trailing on the ground. I'll refix this to the top of the rudders. The engines sounded sweet. I'll try and fit some larger diameter wheels as well.

I'll post the rest during the week.

RE: Double Taco
 

Sorry for the delay but I got caught up with one thing then another, parents night at the school meeting the teachers. The list jusrt seemed endless.
Anyway here's some more:-
These first two photos show the installation of the 4oz fuel tank. The hooks and eyes were given additional strength with a little drop of thin "cyno" added to the hole prior to the hook or "eye" being fixed.
On a test run the positioning was just right for the engine to run smoothly.

All four access hatches have permitted the "radio installation" to be secreted within the wing space.
A consideration for later development is the installation of a centre flap with space available for the servo also within the wing space.
So that's completion of the build and the installation of the radio. So far test runs have just been ground hugging exercises. Alright it failed to take off.
First was down to small wheels and the rudder joing bar, both have been adjusted.

The second attempt was that the one engine was to lean and forced an aborted take off but still managed to break a prop and I didn't have a spare. This weekend I'm hopefull but the weather could be doubtful.

RE: Double Taco
 

Maiden Flight and beyond
Well the "beastie" is now completed and is easy to spot. Several changes have been made to gain flight.
the rudder joining bar has been resited to the top side of the rudders as this was dragging on the ground and prevented take off
the props were increased in size to 9" X 6 as the small props were revving to high
the wheel size was increased as due to much drag was caused with the smaller wheel
an increase in the size of wire used for the under carriage will be required as it is now starting to bend.
the rear tail plane will require some bracing as rudder movement and elevator movement generate an unacceptable amount of flexing
Once airborne the plane is very stable and the control surfaces are adequate for throwing the plane around. It require a little speed for an approach landing. So far I've tried standard circuits, loops and rolls. [I tried a knife edge but one engine cut which gave the opportunity to attempt single engine handling. Of cause all efforts to remember what to do evaporate. So I kept the wings level tried to turn, with some difficulty, cut the throttle and landed (arrived) just off the strip but in one piece.] It's not going to 3D but the comments so far that the engine sound certainly give it some prescience.
Wing Span: 36" + 91/2" centre boom
Engines: .25 BB GMS
Radio Gear:

5 Channel Radio
4 Ball race servos [Futaba 3001]

2 Futaba 148's throttle linked using a "Y"lead

I've set the throws to a comfortable level using exponent ional settings of
-30%

RE: Double Taco
 

I've been thinking, I know dangerous at my age!

Currently the plane flies just great but slightly "speedy" with a "two blader" prop what would the characteristics be like with a three blade prop?

Just to refresh the stats;
2 X .25 GMS engines with 9 X 6 APC props

All thoughts welcome however trial the test will have to wait until the new year as the supplier is on hols as well.

RE: Double Taco
 

Or try a pair of 10-4's The 4 pitch will slow the plane down.

RE: Double Taco
 

John,

Have you had any trouble with your engine run when inverted? It looks like your tanks are really high and the engine would lean out excessively when inverted or in outsides.

On my single Taco, I used a bunch of foam and mounted the tank level with the engine. I did cut the bolts off.

RE: Double Taco
 

I managed to get to the local shop just before they closed on Christmas Eve and bought a couple of three blader 9 X 7 so today the test. wow It is so smooth. Still tends to hug the ground before lift off. Even though I have mixed a little flapperon I still haven't used it yet.

And the sound ......

All I can say is if you get the chance or require the push do have a go. It's not difficult and the "buzz" of flying something unique is very rewarding.
Below are some preflight photos.

Unfortunatey mstroh I coudn't go to a 10" prop 'cos the centre section is only 91/2" beam. I originally designed the plane to use 9" props.

Ed I've never had engine run problem with height of the tank, my Mojo has a similar set up with the carb just below or level with tank outlet. I'll attach a photo.