BH models Mosquito build

getback wrote:Looking GOOD ! Good to see someone is getting some building in , those BHM do usually go together pretty easy and fast . Be watching

Thanks Eric.

Who can resist a little "test fitting".



I'm looking at a lot of leading and trailing edge sanding and thought of roddies "sanding" thread. Found a short piece of PVC and cut it in half, a little contact cement and 150 grit used on a test sample may reduce the effort. If it works I will cut a longer piece.



Bob

Great build Bob, particularly seeing that the original mosquito was also made from Balsa Wood. Pretty much the fastest aircraft of WW11. Watch out!

The following is from www.fighter-planes.com

"Construction
The genius of the aircraft's construction lay in the innovative and somewhat unorthodox use of seemingly commonplace materials and techniques. The bulk of the Mosquito was made of plywood. Stronger and lighter than most grades of plywood, this special plywood was produced by a combination of 3/8" sheets of Ecuadorean balsawood sandwiched between sheets of Canadian birch plywood. Like a deck of cards, sheets of wood alternated with sheets of a special casein-based (later formaldehyde) wood glue.

Forming the fuselage was done in concrete molds. Left and right sides of the fuselage were fitted with bulkheads and structural members separately while the glue cured. Reinforcing was done with hundreds of small brass wood screws. This arrangement greatly simplified the installation of hydraulic lines and other fittings, as the two halves of the fuselage were open for easy access by workers. The two halves of the fuselage were then glued and bolted together, and covered with doped Madapolam fabric.

The wings were also made of wood. To increase strength, the wings were made as one single assembly, onto which the fuselage, once both halves had been mated, was lowered and attached. Metal was used sparingly in the construction of structural elements. It was mostly used in engine mounts and fairings, control surfaces, and of course, brass screws.

The glue used was initially casein-based. It was changed to a formaldehyde-based preparation when the Mosquito was introduced to fighting in semi-tropical and tropical climates, after some unexplained crashes led to the suspicion that the glue was unable to withstand the climate. De Havilland also developed a technique to accelerate the glue drying by heating it using radio waves.

The specialized wood veneer used in the construction of the Mosquito was made by Roddis Manufacturing in Marshfield, Wisconsin, United States. Hamilton Roddis had teams of dexterous young women ironing the (unusually thin) strong wood veneer product before shipping to the UK."

Bob, here I am looking at your work, I really like that step by step job.
I imagine the model with both Enya 09! .... is going to look great !, I was inspired to do something with my Cox 010, maybe in the future make a twin for the 0.010 !!! .... there will be some Flat ?, or will I have to do something on my own?!, Who knows !?
Look Bob, just in a page of my country there is an ENYA for sale zero kilometer, that is, new, that announcement made me agree to You !.
Greetings, Mauricio.-

http://articulo.mercadolibre.com.ar/MLA-651808463-motor-enya-19v-antiguo-glow-coleccion-_JM#D[S:HOME,L:HISTORY,V:6]

rsv1cox wrote:

I decided to actually read and follow the instructions.

Well, that's a novel approach Seems to work out great too

Bob the test fit looks nice i think this is going to be a very fine model in the end , with a 28" W/S it should really schoot if you decide to fly it and i hope you do !

It is with a great deal of trepidation and courage that I even attempt to start a build thread here knowing that for the most part I'm in the company of experts when it comes to model building.  That said I am not adverse to comments both positive and negative regarding this admittedly simple effort.  So I press on.  

I tried out the PVC idea on the wings leading/trailing edges with mixed results but I quickly switched over to my long used sanding block and 100 grit to start with 400 grit finish.  Sanding sealer, primer, base coat, and finish coats yet to come.  









Plans said the nacelles were fragile, and they both arrived broken in the package.





Picked out the engines, mounting structure looks weak, might have to strengthen it up a bit.



I have no idea as to what to use for a fuel tank or how/where to mount it.  I guess a couple of 1-1 1/2 oz triangles would do. Cross that bridge when I get there.  

Yes Rod,  I have been living on a youtube Mosquito diet.  Lot's of good information on an aircraft that I'm mostly unfamiliar with. A favorite for obvious reasons.

https://www.youtube.com/watch?v=MGvjQbBNEE0

Thanks Eric.  And Maurico thanks for the support and the link.  If that was $1300.00 USD I would run away.  

Bob

[quote  And Maurico thanks for the support and the link.  If that was $1300.00 USD I would run away.  

Bob[/quote]

Oh no no Bob!, if they were dollars I would also run away! Haha , the account is like this:
$ 1300 / US$16.4 = US$ 79.26.

Looking really good. also thanks for the lesson on the building of the real Mosquito.

Fueling ideas

But first...Bob...we have seen a lot of examples of your work and craftsmanship...you need Zero trepidation and have plenty enough courage

Tin tank..or tanks..begs where?

Two under wing inside of each engine pylon seem much too low from a pickup to C/L of venturi POV.. above wing is too high

Common tin tank on main Fuselage has same above or below wing VS venturi C/L and adds a LOT of fuel line to each engine

Pressure bladders make the most sense EXCEPT one is real fiddly and TWO would drive me nutz trying to start and go fly so I would opt for One central bladder

A third option is where I most likely would experiment with--- is a common balloon tank hiding outboard above wing center fuselage inside a cigar tube

Thanks Fred, I have never ran bladders and would not know where to start.

I'm thinking two of the smaller wedges hung on the proper side under the wing on the nacelles.



This small flat tank would work under the canopy inside the fuselage but that means long fuel lines.. Also the tank is a clunk and scheduled for my yet to be finished Corsair, and it should be used while upright.



That small wedge tank would not allow for much air time, but with my dizzies that's not a bad thing. Looking for early spring finish time. Going to be some outside spraying and the weather must warm.

Bob

Looking good Bob! Those nacelles worry me though. Do you have any 1/64" plywood that you could "skin" the sides with?

akjgardner wrote:Looking really good. also thanks for the lesson on the building of the real Mosquito.

Sorry to detract from Bob's build thread, but it really is a fascinating aircraft.  All wood for lightness, meaning greater speed.  Lack of skilled metalworkers or aluminium in Britain, but numerous craftsmen who were skilled in wood.  The air mistery completely rejected the concept of the plane but De Haviland pushed on privately without military funding to complete the project in 22 months from the first concept drawings to full production.  The air ministery were absolutely blown away with the aircraft's performance and embraced it, thankfully.

roddie wrote:Looking good Bob! Those nacelles worry me though. Do you have any 1/64" plywood that you could "skin" the sides with?

Me too roddie, in fact I woke up last night thinking about it as I'm working on those nacelles today.  They did supply 1/64" doublers and hardwood bearers in the kit but I'm not sure they are strong enough to handled the .09's.  



Besides, the bearers are not a tight fit inside the balsa.



I have some thin luan plywood and have had good luck sanding off a layer or two to use as doublers in the past.  They say to trace out the doublers then cement on to the balsa and bearers, but I think I will just epoxy as a unit then trim to fit.  If I don't like the strength then I will back it up with one sheet of luan.

I am only going to very lightly sand the nacelles and may not even airfoil them or the fuselage.  

Not a detraction at all Rod, jump right in the waters fine.  I'm learning respect for these "Wooden Wonders." They were made in Australia too.  Wasn't there a very similar "Beaufighter?

Edit add: I had to google my own question.

https://en.wikipedia.org/wiki/Bristol_Beaufighter

Bob

Because of the way it was built, the Mosquito is also a lot smoother on the surface than many metal-clad planes. That obviously helps to improve the top speed. If a flat paintjob "costs" several mph (see http://www.wwiiaircraftperformance.org/mosquito/mosquito.html ), imagine how all the little rivets and gaps must affect to drag on high speeds.

Look at this Spitfire for example and compare it to the surface of a Mosquito:

KariFS wrote:

rsv1cox wrote:

I decided to actually read and follow the instructions.

Well, that's a novel approach Seems to work out great too

BTW Kari,  It didn't take me long to deviate from the plans.

In the second paragraph they said to mount the wing on the fuselage then sand, I didn't like that at all so I sanded the wing au natural. Third paragraph regards the nacelles and you know what I'm doing with that.  10 more paragraphs to go.

PS. Like the picture Kari. Reminds me of Jet pilots expression of "Kick the tires and light the fires." Applies to Spitfires too I guess.

Bob

I love this picture of a Beaufighter cockpit partly because I had one of those Brit canteens, you could wet the fabric covering to keep the contents cool.  



Isn't that a flotation device above the pilots head serving double duty as head padding?

Hijacking my own thread here.

Edit add> Well, a similar canteen.

Today I cut the slots for the elevator hinges using my handy dandy slot cutter.  Cut a dozen slots accurately within two minutes, turned them over and cut again equalizing any irregularities.  Had to use the saw blade instead of the slightly thinner disks because of the harder dowel.  





I round off the hinges glue and pin when installing.

Bob

Oldenginerod wrote:

akjgardner wrote:Looking really good. also thanks for the lesson on the building of the real Mosquito.

Sorry to detract from Bob's build thread, but it really is a fascinating aircraft.  All wood for lightness, meaning greater speed.  Lack of skilled metalworkers or aluminium in Britain, but numerous craftsmen who were skilled in wood.  The air mistery completely rejected the concept of the plane but De Haviland pushed on privately without military funding to complete the project in 22 months from the first concept drawings to full production.  The air ministery were absolutely blown away with the aircraft's performance and embraced it, thankfully.

Rod - Hey thanks for the movie. That's quite a story. Undereducated American, I always assumed the Misquito was just a downsized British version of the P-38 Lightning. Oop's was I wrong.  I appreciate the history lesson.

Double that Rene. It showed the DH Dragon in flight, worth the price of admission alone.

Started on the nacelles, roughed them out and pinned them together for a final sanding. Also set up the engine mount cutouts along the thrust line.





Next step is to glue on all the ancillaries sand and finish.

Bob

I'm trying to figure out how to position the engines. Conventional wisdom says to mount them both outboard to the control line, but I kind of like both of them positioned inboard to the fuselage. What do you think?

I like this myself..  
 My guess is you're NOT using mufflers on these? Can you change the NVA so they both point up ? With this configuration i would use some tip weight ! And as far as the tank one tank duel feed from a T ,better chance they cut out the same time , Just my

Nope, no mufflers Eric, extra weight and drag. The NVA's can be set up or down, I will position them up. First coat of sanding sealer on this morning, probably the only one I will apply.

Some one else agrees with us on engine positions.



I thought about just mounting a couple of Cox .049's on it, but I have all these Enyas going to waste.

Bob

getback wrote:I like this myself..  
 My guess is you're NOT using mufflers on these? Can you change the NVA so they both point up ? With this configuration i would use some tip weight ! And as far as the tank one tank duel feed from a T ,better chance they cut out the same time , Just my

Me Too