edf funfly

as long as it goes better than the twin did, i will be very happy.

Have you been able to check the thrust/weight ratio with the fishing scales yet Tony?

still waiting for the esc to arrive so i can wire it all up and test it.

so it will be a case of getting it in the field and flooring it to see if it gets up enough speed to get off the ground.
if it can rog it will fly ok.

Eric wrote: check the thrust/weight ratio - - - tells you nothing, with an EDF, Pol, cos the fan is effectively stalled! All you can measure when static is the amps drawn. (and the weight, of course!) An EDF doesn't produce much thrust when the airframe is static, it only starts to work as the airspeed comes up.

I was under the impression that they maintained a constant thrust, but you could never achieve the speed of the airflow from the outlet.
I likened them to turbines, & from what little I've read about them, they have to measure them in thrust rather than prop pitch & diameter, because these measurements just don't apply?
We could do with a thread explaining this if anyone is up to it please?

Pol.

So like a diesel turbo you get more boost the more exhaust charges through the exhaust I presume bit like turbo lag.

The Beard wrote: So like a diesel turbo you get more boost the more exhaust charges through the exhaust I presume bit like turbo lag.

Don't want to drift too far from Tony's thread, I was under the impression that the exhaust was far faster than the model could fly .... so the theory about firing something out the back at 1000 mph meant you could go forward at 1000 mph didn't apply.
This may apply to rockets & even NASA have experimented in light speed travel by firing electronic particles out of the back of space ships.... It's called "Ion Drive"
If you have a propeller driven craft, the maximum speed it will do is dependent on the the pitch of the prop & the speed it's turning........ Imagine turning a screw slowly into a piece of wood, it won't go in faster unless you turn it faster or have a higher pitch on the screw.
For those of you who have used an electric screwdriver with a clutch ..... the motor will run at a high speed, the clutch will just slip, how fast that screw turns will depend on the torque applied to it ..... (The thrust)
Has anyone measured the velocity of the exhaust out of an EDF or a turbine? ..... I'll bet it's a lot higher than the velocity of the model.