1/4 Scale Tiger Moth build, a work very much in progress

[Richard Thornton 2]

Some extra weight added to the cockpit.

The aircraft I am modelling has a lovely RAM satellite navigation system holder and an RAF instrument light, which took some initial head scratching as to what it actually was. Fortunately the owner is more than happy to help and you can still purchase the light on eBay but it’s 4 x to big for the model 😈

 

 

Edited April 18 by Richard Thornton 2

[Richard Thornton 2]

1 minute ago, Richard Thornton 2 said:

Some extra weight added to the cockpit.

The aircraft I am modelling has a lovely RAM satellite navigation system holder and an RAF instrument light, which took some initial head scratching as to what it actually was. Fortunately the owner is more than happy to help and you can still purchase the light on eBay but it’s 4 x to big for the model 😈

 

 

The other instrument panel fittings are from Mick Reeves Models and they are fantastic, but have had to renew the dial decals as they have faded, due to being in the sun in my conservatory… well my wife’s conservatory aka my workshop

[Manish Chandrayan]

1 hour ago, Richard Thornton 2 said:

Do you know if anyone has not used them from their Falcon kit build or are they easy to make?

Regarding the grommets, was pulling your leg Richard😀

Falcon kit did not come with the drain grommets. I got them laser cut in fiber. Plan was to install every single one of them, and also burn the drain holes through the fabric. Installed a few and then left them off.

I still have them, let me see if I can post a picture later today, take a look and see if that is what you want. If you decide in affirmative, I can always pop them in an envelope and send it across.

 

[Manish Chandrayan]

Does the instrument light have a working LED bulb inside? (I half expect to hear a "yes")😃

 

Regarding the NGH, if you use it please ensure perfect baffle. The TM cowl opening is as such is not very conducive for model engine rotation direction and on top of that the petrol engines run hotter than glow. 

[Richard Thornton 2]

45 minutes ago, Manish Chandrayan said:

Does the instrument light have a working LED bulb inside? (I half expect to hear a "yes")😃

 

Regarding the NGH, if you use it please ensure perfect baffle. The TM cowl opening is as such is not very conducive for model engine rotation direction and on top of that the petrol engines run hotter than glow. 

Now there was an opportunity lost, I should have thought about popping a light in but realised that I would only be flying during the day. 😏 Leg pulling back!

I attached a photo of the head of the light as it’s a knurled knob, but for gloved fingers and you twist the the barrel to let the light shine. It was easier to make once I had worked out the geometry and had several goes drilling the plastic which is from a number plate. No I am not a womble but I hate waste!

[Simon Chaddock]

Richard 

The reason I asked about the power plant was that for a Gipsy powered plane the prop rotates clockwise when view from the front.

This is the reason that the nose cowling inlet is offset to aid the cooling airflow. When a conventional CCW prop with a scale nose cowling means the cooling airflow is by comparison somewhat restricted, exactly the point raised by Manish.

Of course the cooling may still prove to be adequate but it does rather depend on just how scale you want to be.

Its a bit like the issue of using true scale wing sections. 

[Richard Thornton 2]

1 hour ago, Simon Chaddock said:

Richard 

The reason I asked about the power plant was that for a Gipsy powered plane the prop rotates clockwise when view from the front.

This is the reason that the nose cowling inlet is offset to aid the cooling airflow. When a conventional CCW prop with a scale nose cowling means the cooling airflow is by comparison somewhat restricted, exactly the point raised by Manish.

Of course the cooling may still prove to be adequate but it does rather depend on just how scale you want to be.

Its a bit like the issue of using true scale wing sections. 

Very good point to both you and Manish.

Due to the shape of the cowl, which is really skinny and the upper positioning of the prop shaft, the motor is currently inverted within the engine bay. (I have read some horror stories of starting and running these lumps but I intend to run it in in the upright position, out of the model, and then turn it over and re run it a few times in the inverted position prior to plumping it back in)

By way of compensation for the cooling issue, the cowl was a fully contained one piece fibre glass thing, very scale like but I worried about access to the engine, electrical stuff and most importantly, cooling. So like all good modellers, I cut it into 4 pieces, which I hope will resolve the cooling issue. (my wife asked why I took a perfectly formed cowl and cut it into tiny bits that then had to be jointed with a long piano hing that I had to source…. I am sure she still doesn’t get it)
On the full size, the cowls don’t always marry up which is fine as putting a hinge down both sides for access, when those ‘doors’ are shut, there is now a bit of a gap both fwd and aft where they bulge past the fuselage.

Underside of the cowl has also been modified having a 15mm gap between where the cowl passes over the firewall. 

I am hopping that this all helps promote good airflow through the cowl both by direct airflow going in and Venturi dragging the air going out.

Do you think this is enough?

[Richard Thornton 2]

4 hours ago, Manish Chandrayan said:

Regarding the grommets, was pulling your leg Richard😀

Falcon kit did not come with the drain grommets. I got them laser cut in fiber. Plan was to install every single one of them, and also burn the drain holes through the fabric. Installed a few and then left them off.

I still have them, let me see if I can post a picture later today, take a look and see if that is what you want. If you decide in affirmative, I can always pop them in an envelope and send it across.

 

You are very kind Manish. I think I took the same view as you and thought, what a faff, it’s a scale bit that unless you know they are there, they seem almost invisible.

Talking of which, when I took the photos of the underside of the lower wings, I noticed that the E in the call sign is different from that on the sides of the fuselage.

When I asked the pilot (politely as I didn’t really know him that well at the time) why they were different his response was, I have never noticed, I sit in the back seat and you can’t see the underside from there. 
Another thing, the call sign is not marked on the upper wing surfaces, they simply didn’t get around to doing it!

But I have found out where the first aid box is stowed, and yes, it’s going to be fitted to the model

[Richard Thornton 2]

I have attached some photos of the steps I took to make the Slat brackets. I mentioned before that this was the third attempt but I received a lot of inspiration from the owner of the aircraft not to give up and crack on. I seems only fair to pass this enthusiasm on.

Hopefully the pictures explain everything, A to C are the various stages of the brackets.

D and E are templates to ensure everything evolves into a similar shape.

 

[Manish Chandrayan]

I have a NGH 38. Test ran fine upright on the bench, later installed inverted on a locally made copy of H9 giant stik and ran fine. Not a power house by any means. But was adequate and will be adequate for a quartet TM. On the Stik I chose that engine as I needed all the nose weight so used the metal mount and the engine. Must have had 30/40 flights without any issues till I managed to get a DLE 40cc twin and more power. 

On the TM, if you look from the front the cowl cheeks bulge outwards and they have sufficient gap between them and the fuselage sides. The cheeks being bulged create a low pressure inside the cowl and help extract all the hot air. All you need to ensure is that all the air going in is directed over the fins as closely as possible and it will work fine

[Richard Thornton 2]

3 minutes ago, Manish Chandrayan said:

I have a NGH 38. Test ran fine upright on the bench, later installed inverted on a locally made copy of H9 giant stik and ran fine. Not a power house by any means. But was adequate and will be adequate for a quartet TM. On the Stik I chose that engine as I needed all the nose weight so used the metal mount and the engine. Must have had 30/40 flights without any issues till I managed to get a DLE 40cc twin and more power. 

On the TM, if you look from the front the cowl cheeks bulge outwards and they have sufficient gap between them and the fuselage sides. The cheeks being bulged create a low pressure inside the cowl and help extract all the hot air. All you need to ensure is that all the air going in is directed over the fins as closely as possible and it will work fine

That’s good news, thanks for information as this part of the build isa great unknown. I know most scale models land up being tail heavy and I hope that once the wings are finally covered and assembled, I can put it all back together and get a feel for where the CofG is.