Latest Project

I spent several months researching my next project. In my opinion this is all part of the experience and reward of scale aeromodelling. 
A visit to the archives of the Imperial War Museum in London is worth it alone. If you can get there to research your next model do so. I highly recommend it. You need to book your visit in advance. http://collections.iwm.org.uk/server/show/nav.00g005003

  

The scale model aeroplane I am working on is a De Havilland DH10C, as pictured above. 66'' wing span with twin electric motors. 
The plans have been sorted so no more excuses.
There are a number of potential problems but each new model has these and they provide stimulus for the little grey cells. Being a twin engined aeroplane one needs plenty of tail area in the prop wash. The tailplane is huge so no problem there, but the fin/rudder is not directly in line with the engines so I am relying on the fact that the very large area (8'' high) presented by the fin/rudder will be sufficient. Time will tell.
The tyres have a very distinctive tread, similar to the front tyre of a tractor, so I will have to swat up on moulding rubber.
There is a huge angle of incidence on the wings and tailplane to deal with so it is possible that the model will fly very nose down. I assume the real aeroplane did.

Start Date 1st May 2006

I usually start with the tail surfaces and this is no exception. I find this gives me a good intro' to the build as it is straight forward. There is nothing innovative about these surfaces and are standard sandwich construction with just a tweak up on the wood sizes as they are relatively large. I've had to adjust the notoriously difficult DH fin/rudder shape from the drawings as the leading edge was found to be too rounded when viewing the photographs. Note the rectangular hole in the rudder. On some 10s it was found that the balance was too powerful so they simply cut a hole to reduce it's effectiveness.

The next step was the huge tailplane. Same build as the fin/rudder.

One set of wing ribs. 
There are twice as many riblets but these are made from strip balsa and then sanded to shape once stuck in place.

April 28th 2007. It has taken some time but the wings are almost complete. The wing roots, wing dowels and interplane strut anchorages will be fitted when the fuselage is complete.
                    
Wing construction is in my usual way plus I've used carbon fibre for the first time for the leading edge, trailing edge and rib caps.
I am very impressed with the improvement over balsa as it is very straight and taught.
The rib caps seem to make the delicate 1/32nd ribs bullet proof.
A note on the construction of the trailing edge. The carbon is very thin and there is not much to adhere too so I fitted a light 1/32nd strip of balsa on the inside edge. The rib caps must go from the very outside of the leading edge to the trailing edge to lock it all together. You will notice a very fine balsa strip on the trailing edge. This is to create an edge on the top surface so that the covering maintains a nice sharp contour and does not stick to the full width of the trailing edge.

As previously mentioned the tyres on the 10 are of a particular and unusual shape and appear to resemble the front tyres on a farm tractor. In the photo is the finished balsa tyre that I turned with an electric drill. I made up 4 x 3mm hard balsa rings of the appropriate size and the centre one being a disc to which I cynoed a dowel to hold in the chuck of the drill. Once I had shaped the tyre I removed the centre disc and finished the inner shape by hand. It is finished with 3 coats of sanding sealer. As the saying goes "I know a man who can" so I am going to pick his brains and attempt to mould the tyres in rubber. We will see what happens.
A quick word of advise to all modellers that value their relationship with their partners.
If you use this method of making the wheels / tyres do it outdoors as "her indoors" will go bonkers because the sanding dust spreads EVERYWHERE. You've been warned.

Things that make you go Hmmm!?!?
A lot of thinking spent on this bit as it is critical to get it right. The lower inner wings support everything i.e. motors, undercarriage and top wing. With the experience gained in building the Handley Page I have applied very similar techniques but tried to reduce weight where possible. The H.P. is over engineered and consequently rather heavy. 
The fuselage is now beginning to take shape. As you can see the two basic sides are made and are loosely held together by the wing spars.

Inner wing spars are double the size being two laminated together. The thinner rear spar has 18 swg piano wire re-enforcements going through the centre. Trailing edge is a 25mm wide .8mm balsa with carbon fibre trailing edge.

Getting there.

November 2007. Model weighs 18ozs in the photo but there is a lot of work to do. You can see that it is all wing and it should float well. The motors will be brushless and powered by li-po batteries. Using the "new" technology, the weight of the electrics will be half of the Handley Page power set up.