Blohm & Voss BV 141 Project

[ramses]

Build tread of a rubber-powered free-flight scale model of a Blohm & Voss BV 141

This project (and build thread) actually is a bit like the Fokker D.XXIII project.
The prototype of the project has already flown before I started the build tread...
But after the prototype I will make a new version in which I take into account what I noticed with the prototype.
I will first supplement this build thread with the construction of the prototype to its current state.
Then I continue this build thread with the second BV141 model

I have downloaded the plans from the Outerzone website, model details:

Blohm und Voss BV 141
Free flight scale model of the WWII German reconnaissance plane.
Design: Al Lidberg
Year: 1987
Spring: 28" / 71cm



You would expect it to be a one-off experimental test model... but nothing could be further from the truth.
Some photos of the original:











In Photoshop, I placed the fuselage ribs, wing ribs, etc. on an A3 sheet.
I printed this with the laser printer so that I can make the printwood myself again with the clothing iron:



The plans placed over the building board:



The self made printwood:



Grabbed a fresh scalpel and started cutting out the parts:



Making the wingribs:



Ready to start building the BV-141:



Cheers, Ramses

[ramses]

Start build of the Blohm & Voss BV 141

I started with the gondola or "crew compartment":



Test fitting and glueing the half fuselage formers one by one:



Main structure of the gondola made, the vertical frames in the nose are next:



Added the vertical frames:



Gave the gondola a very light mist of white overall.
Started covering the gondola with tissue... it's not much covering, almost everything will be 'glass' soon:



Gave the tissue two coats of dope and started on the 'engine fuselage':



Cheers, Ramses

[ramses]

Fuselage(s) construction:

Glued the stringers to the left half of the engine fuselage:



Took the left fuselage half from the building board and added the right side:



The fuselage(s) of the BV-141:





The infills behind the engine cowling and the infills where the wing passes through the fuselage are made of 1.5mm balsa. Started with the vertical stabilizer:



Finishing the vertical stabilizer:



Cheers, Ramses

[pb_guy]

Wow! Great work on your project. I love asymmetric aircraft. 
ian

[Istvann]

How did you ironed on the laser print? I've tried it many times, but without succes, or with very marginal effort.

[dputt7]

They are great flyers. I built one towards the end of last Century and it just about flew straight off the board.
.

[calgoddard]

ramses -

You did excellentn work on your BV 141 model.

For inspiration, this is a picture of the Blohm & Voss BV 141 built by my good friend Robert Hodes in the US. It is sitting on a judging table at the WESTFAC VIII Flying Aces Club contest held in 2021 in Buckeye, Arizona.

[ramses]

Thanks for the nice replies!

I love asymmetric aircraft. 
ian

Me too! Blohm & Voss and Burt Rutan made some very fine asymmetric designs.

How did you ironed on the laser print? I've tried it many times, but without succes, or with very marginal effort.

You have to use an iron which gets really hot!
I tried it with a Jamara covering iron, but that one doesn`t get hot enough.
I bought an old clothing iron at a second hand store and at the " *** linnen" seting it works fine.

They are great flyers. I built one towards the end of last Century and it just about flew straight off the board.

I was really amazed how well the BV-141 prototype flew.
As you said, straight off the board!
And easier to trim than a lot of other conventional designs...

For inspiration, this is a picture of the Blohm & Voss BV 141 built by my good friend Robert Hodes in the US. It is sitting on a judging table at the WESTFAC VIII Flying Aces Club contest held in 2021 in Buckeye, Arizona.

WOW!   That`s a beauty 
Love the splinter camouflage.
AND, for indoor flying!
How does the BV-141 perform indoors?
It looks like it`s build from the Al Lidberg plans too?

Cheers, Ramses

[Spiros]

Well done Ramses! WOW what a neat job!!! Excellent!

[ramses]

Thanks Spiros!

Cheers, Ramses

[ramses]

Horizontal stabilizer and wing construction:

Horizontal stabilizer and elevator made over the plans, and started with the wing assembly. I first built the wing flat over the plans, then slide it through the gondola and engine fuselage:



The flat wing center section has been glued in place, however the spars etc. of the wingtips have not been glued yet:



The wing has dihedral at the wingtips. Given how the gondola and engine fuselage are constructed, you cannot slide the wing with dihedral through them...

So, i build the wing flat first, then slide it through the gondola and engine fuselage, and only then make the tips with dihedral. But once the cockpit and engine fuselage are attached to the wing, the wing can no longer lie flat on the workbench...
That of course is necessary, so I made a kind of a wing jig:



First i made the base of the jig; the new building board with built-in dihedral will be placed on top of this:



First i put the entire plank on, then removed the sections where the cockpit and engine fuselage will go:



The BV-141 fixed to the jig and the wing tips finished with the correct dihedral:



On the advice of Lars Tolkstam, I purchased this beautiful book about the BV-141:



Cheers, Ramses

[ramses]

At the junction of the gondola and the engine fuselage with the wing, some infills were needed to attach the tissue. I also want adjustable ailerons on this BV-141, so those still needed to be scratched:



Infills and ailerons done:





Lightly sanding everything one more time, then the BV-141 is ready for tissue:



Cheers, Ramses

[ramses]

Covering the BV-141:

The tissue i used for this BV-141 are old sheets of VERON tissue.
Not the best, but good enough for this prototype.
I started with the underside of the wing:



I glued the tissue to the balsa frame with a glue-stick.
Fuselage next:



Finally, the last piece of tissue and then everything is covered.
I find covering with tissue nice work to do:



The wing construction board was raised to fixate the wing in place after dopeing.
A board was also made to fixate the rest of the parts in place after dopeing:



Everything has been given a first coat of 50% diluted dope and is fixed to the boards to dry:



Cheers, Ramses

[ramses]

For the second (final) coat, I mixed in a very little light grey Humbrol to the dope:



Left to dry for a week:



Cheers, Ramses

[ramses]

Glued the empennage to the engine fuselage and made the landing gear:



The main landing gear in the wing and the tail wheel in the fuselage were made according to the plans. Wing fairings were made from 0.8mm balsa and the cockpit painted dark green on the inside. There is a lot of glass in the greenhouse, so something definitely needs to be done on the inside.

I am not going to make an elaborate scale cockpit for this test model, but I do want to put a (simulated) pilot, navigator, and gunner in it. And this time, full-body pilots, no busts. Made a sketch and transferred it onto a piece of foam:



The pilot, navigator, and gunner roughly cut out:



I thought I could shape the foam with the Dremel, but unfortunately, that didn't work at all. This foam isn't really suitable for this; it's too coarse and too flexible... Sanding didn't work either, so I (very) roughly shaped the little pilots entirely with a scalpel:



First, just to test if Humbol and Revell paint don't melt the foam. I applied it very thickly but there was no reaction; the pilots can be painted:



First a base coat of blue/grey Humbrol overall:



Then the rest of the colors:



Put the pilot in a seat and given him rudder pedals:



The pilot (in front of the CG) weighs 2.02g, the navigator (on the CG) weighs 1.11g, and the little tail gunner less than a gram:



The figures are very rough but at least there is something in the gondola...

Cheers, Ramses