Freewing EDF Group

Another couple of flights with the Sabre. An 1800 lipo used 670 mAh on a 2 minute flight so 5 minutes may be possible depending on how you want to stress your batteries.
A left hand over-hand launch seems to be the way to go, at the risk of giving it a girly chuck, but you need to get the power right to avoid disappointment.
It appears that a number of people are using cheat holes; I'm going to try running mine without the canopy to see what affect that might have. Any way its still in one piece so all good..

I don't know enough about edfs but have read that some manufacturers add increased airflow for better static thrust at the expense of top speed. When Jon and big Dave flew side by side there was little difference in flight with canopy on or off.

The difference in static thrust is evident when doing a ground run canopy on vs canopy off, which would obviously help during launch. However, if there is a trade off with top speed then that's a harder decision.

I've launched Jon's Mig (maiden and second flight). Simon's Sabre using the underarm method and my Thunderchief. I think that the correct c.f. and some up prior to launch makes then all easy. Just make sure you have enough power...I don't get the logic(?) of letting go on part throttle.

As far as I'm aware (and I'm no expert) the rational of using part throttle is that at full throttle the fan is stalled and produces excessive torque reaction (or is it gyroscopic precession, I'm not sure) for no gain in acceleration at a time when there is insufficient airflow over the wings to counteract it

It’s a static thrust vs dynamic thrust toss up. There was a book called ‘Ducted Fans’ by David James which stated some maths that helped you work out optimum inlet area vs fan size vs outlet diameter. Sometimes an acetate sheet rolled to give a smaller outlet can help increase the top end speed but it has to be right!

I have cut a cheat hole in the bottom of mine, I definitely noticed an improvement in thrust, but can't say I noticed any reduction in airspeed. I would recommend it

Is adding cheat holes as bad as installing a gyro?

I've done a lot of hand launching over the years due to my commitment to electric models without wheels. I can assure you that there is virtually no torque effect on these small edfs. It's up to the individual, but I'll be launching at full power.

MikeSeale wrote: I've done a lot of hand launching over the years due to my commitment to electric models without wheels. I can assure you that there is virtually no torque effect on these small edfs. It's up to the individual, but I'll be launching at full power.

Ok game on: no cheat holes, no gyro, full power, but I'm still doing over arm launches. We shall discover which arguments are testicular in nature.