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[How to] Thrust estimation

Hello everybody,

I just finished my first Delta called Pibros from the plans i took from:

I put ESC, receiver, servos and 2S LiPo on it and it weights 350 grams.

Then i tare my weight and run motor at full speed causing plane to push on weight plate.
Weight showed 175 grams.

The question is: for 350 grams heavy Delta is 175 grams of thrust acceptional to make it flying?
I haven't flown it yet.

thanks for info or any links to places where I can get knowlege about thrust estimation.



How many letters do we ge
These delta have worked with speed.400 brushed motors which are relatively weak though I used to use them.for 700g gliders.

I reckon it should be ok, not powerful but possible.

Have built at least 2 of these, great plane.

thanks for an info.
I hope i will try this out this weekend.

What does it mean "class 400 motor". What does 400 mean? Is it related to wiegth, thrust or KV?



Junior Member
He means size/performance.

400 class would be 22-28mm in diameter and about 60g

300-370 sized motors around typically around 50g and can range from 22mm to 24mm in diameter. As you go higher in class, the motors get heavier/larger and they become more amp hungry and require larger batteries.

It depends on what you want it to do: Do you want long flight times, or do you want short flight times and blazing speed?

That wing you linked looks tiny, so I wouldn't recommend putting a 400 class motor on it unless you plan on running it on 3S.

If you want good speed for that weight on a 2S system, I would recommend this motor:

hexTronik 24gram Brushless Outrunner 3000kv (aka the 24g Blue Wonder)
thanks for a great explanation.
where can I get such infomation which motors and what factors are representing which class?

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