Timos Typhoon FMT Bauplanmodell

raymon

User
how mutch wight your tempest? mine is nouw 1300 gram and my dads 1250. both with 4cc engine. mine is a little tail heavy,
 
It will fly with that weight, Raymon. But they’re heavier than previous models. Should be around 900 grams for an OS20FP and around 1000 for the OS25FX. Do you have some details and pictures (servos, balsa weight, modifications?

Timo
 

raymon

User
I have 2 wing servos 20gram for aileron 2x 15 gram for ailevator and 1x 20 for trotle os .25
Havey balsa at the frond and light balsa tail.

No mods only aileron servos flat in the wing.
 
What accumulator size do you use?
Wood glue? Or two component epoxy glue?

Not much difference to mine. I had 9 gram servos for ailerons, 15 gram for elevator/motor. 10-13 grams metal gear should be perfect.

Bringing the weight down for contest isn’t easy. Especially since aircombat models should be tough and robust. Little improvements add up to a good result.

Timo
 

raymon

User
Most of the glu was second glue. Motor unit woth epoxi for the fuel.

Batttery is a lifepo 2cell its little heavy but he is at the same place of the tank. And i need that wight for cg
 
It really is a few grams here, a few grams there. which add to a heavier weight. Experience helps bringing weight down :-)

Light balsa reduces the weight of the basic wooden model around 1/3. The complete model can be built with light wood glue. Heavy epoxy is only needed if glass fibre is used to strengthen the wing joiners. There are lighter options than epoxy to make the motor compartment fuel save.

Where have you placed servos and receiver? What kind of servo linkage did you use for elevator?
For my .15 version of the Typhoon I had put a small 4x 350 mAh NiCd in the cooler below the motor.

As I said before, it will fly fine with that weight.
But don't make the first flights with a tail heavy center of gravity. Tail heavy helps for tight turns and low landing speed, but you should make only small changes to the center of gravity.

Timo
 

raymon

User
What is the richt cg? 55 to 60mm on the plan but 1/3 is 76mm
If i take 60mm there must me 200grams extra wight at the nose. 1/4 are 57mm.
 

raymon

User
IMG-20210328-WA0009.jpeg


IMG-20210328-WA0004.jpeg


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I have now the CG on 1/3 same as the hellcat.
The plan say 1/4 55 to 60mm
Now 1/3 74mm.
hellcat has also 1/3. Same distance leading edge to nose edge
IMG-20210328-WA0006.jpeg
 
The wing taper of the Tempest is slightly forward, so 1/3 will be tail heavy. The plan gives only an estimation, since I haven't build it on my own, yet. But I sent a message to Pascal who's Tempest is already flying, to measure center of gravity of his model.


Timo
 
Pascal just wrote back, his weight is 1110 grams and center of gravity is 70 mm from the leading edge. From an earlier response, I know his Tempest is very manouverable, so it seems the center of gravity is at a rear point.

Looking good with British markings :-)

Timo

(Bild ist von Pascal F.)

cog.jpg
 

Wilf

User
Engine Mount

@raymon: The engine mount at your Hawkers is more or less upright.
How about mounting the engine in upside down position?
 

japim

User
Engine Mount

@raymon: The engine mount at your Hawkers is more or less upright.
How about mounting the engine in upside down position?
Engine mounted up-side-down is very impractical and problematic. When you fly alone - with no rush @ take-off then OK - and it looks nice. But for aircombat plane you use the simpliest and most robust solutions. Flooding/problems with starting/ rotating plane up-side-down to start the motor correctly/ much more prone to damage at landing etc - just a few I can name and I have experienced when mounted motor up-side-down.
 
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