Peter G Simpson

So did I. On my first spitfire I used the system shown on the plan and interpreted it as having to put a bolt through the leading edge of the wing. It meant taking the cowl off to bolt the wing in place (I probably misunderstood the plan). On my next one and also my P40 I used a pair of dowels in the conventional way and they always worked fine.

On my second spitfire i simply sandwiched 1/32” ply between the 1/4” balsa forward fuselage, which is what I recommend to builders of this plan. On my most recent build I built the forward fuselage around a 1/8” ply structure shown below.

The fairing is undoubtedly very frustrating. If you use planking then it is really hard to sand it to a smooth profile without removing too much material. I used pretty much the same process as Gary B, 1/16” balsa sheeting soaked and pre-bent around a Halfords rattle can. I used 1/32 ply base and 1/16 balsa skins that are faired into the ply. There is a step bigger than an actual spitfire panel line, but in practical terms a razor sharp edge would is vulnerable to hangar rash and not really noticeable on the finished model. Something else to consider early on, My first BT Spit had smaller wheels and did tend to nose over if the grass was too long. On a couple of occasions the nose snapped off behind the firewall. This is because that is basically just a 1/4” balsa box. So it is well worth laminating some 1/32 ply with the 1/4” balsa sheet box to reinforce the area. I did go a bit further with mine and substantially redesigned the fuselage construction to reduce tail weight. But used a 1/8” ply structure to support the firewall.

Hi Richard, it does not seem to have a tendency to nose over. I have seen spits with this problem, but I think it was down to lack of undercarriage forward rake. The CofG is quite near to the centerline of the wheel, and if retract angle is only 90 degrees, which are more common retracts, then it can lead to not enough forward rake. I have it balanced as per plan and characteristics are just right. I found a video of one of the early flights of my Spitfire at Smeatharpe Aerodrome. This was before I got the engine running quite right, it was running a little rich which is why there are a couple of coughs, but after I got it tuned right the engine runs very sweetly.

One final suggestion.... not wanting to hijack your thread Gary... I always struggled with balancing aircraft, particularly low wingers. It's easy to identify CofG on the plan, but once the model is complete not so easy. Secondly supporting the aircraft during the process of balancing. So for my latest builds I incorporate a brass tube into the wing at the correct CofG. The tube passes through the wing so that I can easily string up the model and check the CofG whenever I make any changes to the installation. In the below picture, note the component tray on the top of the cowl at the same position where ballast will be placed. I can then load up the tray until the aircraft hangs level and cycle the gear to check shift in CofG.

I love the BT 69" Spitfire 1a, I have built three of them. The first used an old Laser 100 which had plenty of power for pulling it round the sky and never stopped. It was tall so the cylinder head rubbed in the inside of the cowl. The most recent example I built 2 years ago uses a laser 120 which is shorter and doesn't rub on the cowl. I firmly believe that a Laser 80 would power the spit, but agree with Jon that it would be underpowered so conditions would need to be right! A good argument for the 120 is that, regardless of me building the tailfeathers extremely light, I still needed nose weight... so if the 120 fits why not use it and take advantage of its extra mass. The first two used Unitract Retracts, which worked very well. For my recent build I just couldn't get hold of any Unitracts. I did managed to get John Hope on the phone once, he promised to make a set for me, but nothing came of it. So I set about building my own set. I'm no mechanical engineer, but I fancied the challenge and the result turned out well. I bought a set of 130mm oleos from hobbyking (SKU:344000018) and 100mm radioactive airwheels. the correct wheel for 1/6.4 would be 3.82" x 1.2" but such a wheel is not available. On the first Spit I used 3.5" wheel but it looked too small so this time I used 4" x 1.5" instead. The wider wheel does make fitting it in the wing a bit tight, but it works. After studying the plan it looks like BT intended the leg to lies parallel to the U/C bearers when up, so I ended up with a drawing which I shall publish here in case anyone else wants to build one.

That is beginning to sound pretty nice, I used to own a 160v and it was such a sweet engine. I presume that the 160 would also be 230mm long as the 80 & 100 single are both the same length. A pair of 9oz tanks would just fit into the tank bay at carb height. Would the 160 in line swing an 18/19" prop comfortably. I'm not insistent on turning a scale diameter propeller, as long as it is not stupidly small. My previous P51d swung a 19" prop and looked OK. I prefer 2 blade props, because at some point the plane will make a wheels up landing for whatever reason and I don't fancy the idea of it costing a prop in the process.

On rainy days like this one i start playing around plans - look what fell into the cowling of my P51b. The aircraft is drawn to 1/6 scale and with the Laser 200. The prop would be only 2" short of a scale diameter. I can't help feeling that it would be well over powered? The last P51 I built at this size was ZG38 powered, the ZG38 weighed in at 2Kg and the aircraft needed weight in the tail! The all up aircraft weight was about 8Kg up. I imagine the Laser would be lighter than this so maybe it would be a good match.

It’s a perfect flying day in Devon, so I’ve been out flying my latest lockdown model, this P40 from the Brian Taylor plan. It’s 64” wingspan and powered by an Irvine 61. It is not a detailed scale model as I was aiming for a sports model based on a scale outline so for example control surface hinges are robust rather than scale. She flys beautifully and full flap landings are a real joy. Circuits and bumps were the order of the data today. The Robart 615 twist and turn retracts work ok, but seem a little fragile!

Posted by Danny Fenton on 21/06/2020 21:47:17: You don't see many build Brian's P-40, how does it perform, and what engine?? Thanks Danny, I built it because I really wanted to find out how the P40 flys, but as a ‘sports’ model based on the Taylor P40, so there is very little scale detail on my model, but the outline is as per BT’s design. I wanted to see if the short tail would be an issue but it really isn’t and it flys really well and the flaps are really effective. I fitted an Irvine 61 2 stroke an it is plenty powerful enough for a decent climb, though the 12” prop looks very silly. The stock silencer fits perfectly within the chin cowling. Even with the lightweight engine I had to put weight in the tail for balancing. She came out at 8Lbs ready to fly with Robert 615 twisty turny retracts.