Topflight P47 Build

[Mike S]

So decided on using snakes on the elevator & rudder but not sure which size to order. The ailerons use a a system installed in the wings as do the flaps. The throttle uses a rod so will go with that..

So after looking the through the servo box to see what I have free to use I found the following:

2x148s servos
1x 3003 servo.

These servos are old and have seen better days. I think the S148's are better than the 3003/3001 so I go with these I will order seven new ones. I need a servo for the tail wheel retract but have a few Hitec metal mini servos that would work well.

I also need to decided on a fuel tank for the Laser 100 that will fit in the P47 but not sure of the capacity needed. The place for the tank is pretty large so packing out with foam will not be a problem.

Once the wings are built but unskinned and servos are installed I will decide on the length of servo extentions required for the aileron and flap servos and build in Gareth's idea of securing the servo leads from falling in the wings.

I also need to order the wheels and as the building the wings is only around the corner I need to decided on the suggested 3-1/4" or the harder to build 4" scale size. I think once the ribs and spars are in place I can work out the best size of wheel. However I do think a P47 with under size wheels will look silly and also will give handling problems.

Hmmm lots to think about.

[Russ]

Re the Laser 100 installation, here are some tips I got from former member Tony Scott, who owned several Lasers. when I was installing one in an Extra 300. 

As far as the Laser goes, just follow the instructions for a good result. I run my engines in on a stand (an old sideboard) for the first 3 thankfully, using the recommended 15 x 8 prop (Master Classic or APC work well). The carb settings are usually fine to start the engine but I open the needle valve another 1/2 turn for the first thankful, being sure to vary the engine speed from time to time during the run. Subsequently, I progressively lean out the needle to the factory setting (about 2 1/2 turns) and find that this setting is usually fine for flying. I do tend to run my Lasers on the rich side, especially when cowled, for a margin of protection against overheating. In any case, these engines are not very critical to needle settings. As for the cowling, just be sure to follow the golden rule that the air outlet area should be about 2 1/2 times the air inlet area. On the Extra, this meant that I blanked off all the cowl inlets except the one adjacent to the engine cylinder head. It works great this way. 

He also recommend a 14oz tank which I went with. Gives 10-12 mins flight time.

[Mike S]

Very useful information. Thanks Russ

[Mike S]

Things have slowed down a bit on the build. I want to start on the wings but must finish the fuse first so once the parts arrived I can continue to build.

Parts order:
7 x servos all futaba.
Sullivan snakes. x 3
Wheels 2x 4" scale & 1x 2" scale wheel.

Things to order later on:
Lite weight glass covering
Epoxy mix and thinners, primer with filler & paints for spraying.
Decals to be ordered.

[Mike S]

Today ordered the parts to complete the fuse and start on the wing.

Spoke to John at Laser today to confirm the fuel tank size. He suggested that a 9oz would be ok for the Laser 100. My engine is nearly ready but was delayed due to a broken cnc machine that bores the ports. It should be test running as we speak.
Parts Ordered.
Decided on SLEC 11oz fuel tank.
Ordered another three s148's for the ailerons and rudder/tail wheel combonation.
Sullivan snakes will replace the supplied control rods. 2-56 clevis look to be fine for up to 10lb aircraft.
Wheels orderd are 3.3/4" size as 4" will be very tight to fit.
Mylar hinges just because some how I have used 24 of them somewhere.

[MikeH]

Just be careful of balsa used around the tail -  tends to be not that great (heavy)

I found my TF AT 6 Texan was very tail heavy I had to drill lightning holes to combat that plus I went for an RCV 90 CD because it is shorter
requiring me to add a block of wood to the firewall to ensure the engine was far enough forward which helped by not having to add lead in the nose