DH-98 Mosquito Build

This is my build of the Tony Nijhuis 46” De Havilland Mosquito.  Here’s a link to Tony’s site where you can buy the kit or just the plan http://www.tonynijhuisdesigns.co.uk/multies.htm.  It was a free plan in RCM&E in the June 2005 edition.

Update 2021 I’ve repaired the damage, upgraded the motors and repainted her as a Photo Reconnaissance Mosquito. Full details further down. The maiden flight was a complete success on the 14th of August 2021. Nearly 5 years since the crash.

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Mosquito History

The real Mosquito was known as the wooden wonder and was the fastest fighter available.  Metals were in short supply during World War 2 but there was an abundance of woodworkers and cabinet makers so the Mosquito was made mostly of wood.  It consisted of a lamination of Balsa and plywood which is a good choice for an RC model. 

The Mosquito was an instant success and was used in many roles, even an airliner by BOAC! The photo Reconnaissance (PR) version could fly longer missions with a navigator to aid the pilot.  PR version as all PR aircraft was unarmed to reduce weight so higher altitudes and speeds could be obtained.

The kit I purchased

I like Tony’s kits because nearly all have been an RCM&E commissioned design so you have a good write-up and the build instructions.  I’d already built Tony’s BAE Hawk and after 9 years it was still flying as good as the first day.  Some videos of her are on this website. I sold her as I now fly electric-only, but I’m building another. Details here

I purchased the CNC wood pack and decided to go electric eventually, I was considering the IC version but I thought the risk of one engine cutting out and crashing the model pushed me electric.  The motors, ESC and props from 4-max http://www.4-max.co.uk/tn-multies.htm.  4-Max have recommended setups for all of Tony’s designs.  Update – motors now recommended have been changed from in-runners to out-runners.  I’ve had issues with the original setup that’s ended in some damage see below.

Here are the fuselage build pictures.

There’s nothing too difficult just make sure when you pull the tail together it’s on the centre line of the fuselage.  I used my laser to make sure.

Build pictures of Nacelles

Wing build and one almost ready

Starting to go together now

Painted

The model was covered in Solarfilm and then a coat of Prymol was applied to etch the film.  I then used an airbrush to apply the paint.  The paints I obtained from B&Q in the UK are just tester pots. You can have these matched to the colour you need.   These are tinned with water to the consistency of skimmed milk and then applied in several light coats.  

I painted the whole model in the underside colour first and then masked it off for camouflage.    It’s best to apply the dark colours last.  The only problem with the tester pots is that the finish is matt which is OK but it tends to attract dust   So after all the colours had been applied and left for a few days to dry I air-brushed a gloss water-based varnish.  This just gave a slight sheen to the finish and didn’t look glossy.

Finished

Here she is finished in the markings EG-Y the only flying Mosquito in the world.  Restored in New Zealand and now based in the USA.

Maiden Flight

The flight went well after a scary launch since then have had a couple more.  She files well and looks great in the air.

Brushless Motor problems

The motor installation on the in-runners isn’t ideal.  I had some screws with washers going through the plywood engine ring. Well, the distance between these screws is small and there isn’t much to bite on.  After a few flights, these worked loose and I had an engine failure in flight.  I managed to land safely by throttling back on the running motor. 

I decided to find a better solution and built some adapters on my CNC router. These were better but I had them come loose again even with blue Loctite.  4-max doesn’t recommend in-runners anymore and is now specifying out-runners with 8×4 props.   So I repaired the model and swapped it to brushless 1250kv out runners on 8×4 props.

The Mosquito has been on my wishlist for a long time and I was a little gutted that she’s damaged. I’m a bit of a war bird fan not because I like war but my Dad saw the tail end of it and told me some great stories of his days in the Army.  At the age of 17, he was driving a truck with Spitfire parts from London to Birmingham and then was called up.  It used to take all day in those days to do one delivery.

Repairs and Repaint

After quite a long time sitting on the bench, I finally made a start on the repairs in Dec 2019. The main area of damage was the nacelles with one broken off and the other becoming detached on one side.

With some PVA glue and some balsa, I was able to get the nacelles back together and attached to the wings.

I’ve also decided to modify the nose, it’s damaged anyway and repaint her as PRU (Photo Reconnaissance Unit) Mosquito in PRU Blue. These and the Spitfires were among the best aircraft for Photo Reconnaissance work during World War 2.

I designed some new motor mounts with Fusion 360 and then printed them on my Creality CR10 V2 3d printer. The maiden flight of the repairs and new motors flight was delayed for several months due to Covid-19.