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Old Jun 15, 2012, 08:41 AM
Grand-Duchy of Luxembourg
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Joined Sep 2005
261 Posts
I concede I have limited understanding of aerodynamics, but is there a point in shutting down the edf unit at all in flight?

Shouldn't the fan deliver at least as much 'blow' as the actual speed of the glider, this in order to reduce drag AND avoid turbulences towards the V-tail and reducing effectiveness of rudder/elevator?

Or will the shutdown of the edf-unit (with blades stopped) create a steady tunneled airflow towards said tail surfaces, increasing/maintaining their effectiveness?
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Last edited by Aender69; Jun 15, 2012 at 08:57 AM.
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Old Jun 15, 2012, 09:17 AM
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Canada
Joined Jul 2009
6,225 Posts
Quote:
Originally Posted by Aender69 View Post
I concede I have limited understanding of aerodynamics, but is there a point in shutting down the edf unit at all in flight?

Shouldn't the fan deliver at least as much 'blow' as the actual speed of the glider, this in order to reduce drag AND avoid turbulences towards the V-tail and reducing effectiveness of rudder/elevator?

Or will the shutdown of the edf-unit (with blades stopped) create a steady tunneled airflow towards said tail surfaces, increasing/maintaining their effectiveness?
This shouldn't be your average EDF. It's a glider. I plan on taking it up as high as I usually do and shutting off the motor and letting it be a sailplane. If you're planning to fly it in an aerobatic manner, you're not going to shut it off anyway. You're not flying it like a glider anymore.
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Old Jun 15, 2012, 09:33 AM
Ask me about my FPV addiction
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United States, MN, Wayzata
Joined May 2011
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My fathers and mine were both shipped out last night hopefully we will have them sometime late next week.

Cheers
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Old Jun 15, 2012, 10:52 AM
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My fathers and mine were both shipped out last night hopefully we will have them sometime late next week.

Cheers
Father's day gifts to yourself and your father?

Gambler
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Old Jun 15, 2012, 02:56 PM
Ask me about my FPV addiction
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United States, MN, Wayzata
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Originally Posted by RCGambler View Post
Father's day gifts to yourself and your father?

Gambler
Fathers day is in 2 days I dont think it will arrive by then besides he already knows about it :P
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Old Jun 15, 2012, 04:47 PM
madjeff
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United Kingdom, Stockton-on-Tees
Joined Mar 2008
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well thanks to CS my order has been resolved in less than 24hrs and refunded my first order. good news is my second order is shipped and on its way. now the wait begins.hope customs don't keep it for to long.
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Old Jun 15, 2012, 05:03 PM
R.C. Aviation Fanatic
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Canada
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You guys think this would be quicker than stock habu?
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Old Jun 15, 2012, 06:36 PM
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Adelaide Plains Australia
Joined Dec 2007
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Originally Posted by Razors edge 29 View Post
You guys think this would be quicker than stock habu?
checking the video clip out i'm sure some speed has been added to a few of the very short edited clips to give the impression of a very fast plane. they also might have just used 5 really high speed passes then edited the 1 sec clips together so it gives the impression of it going super fast. there is one point in the vid when it flys by and goes up and this part it looks like it's real speed.

it is going to be great to read all the reports on this beauty to see how close to the video it's speed really is

This video is a very slick, well produced, heavily edited video well done guys i love it and no matter what soon as i have a spare $170 i will be ordering one i have been talking for ages with my mates about a purpous built EDF Glider and it looks like Duafly has come to the table a must have for me thats for sure

cheers chuck
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Old Jun 15, 2012, 06:40 PM
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Canada
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I dunno, the Habu flies on 4S and is much more streamlined. The V70 flies on 3S and is a sailplane. I think you need more "HP" to make a shape like a sailplane go quicker or faster than a shape like a "jet".
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Old Jun 15, 2012, 06:48 PM
UK Commercial RPAS Pilot
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United Kingdom, England, Carlisle
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To be honest.....it's faster than a lot of foamy 4s EDF jet's out there.
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Old Jun 15, 2012, 07:15 PM
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As you know from the other thread, I also have the Vampire and it's a screamer. Given the same size fan and both are from Durafly, slightly different motors, amped almost the same, I still think the V70 will be a bit slower (which I'm hoping) due to the sailplane wings. I'll know when I get mine to compare.
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Old Jun 15, 2012, 07:27 PM
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Australia, VIC, Melbourne
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Originally Posted by xviper View Post
This shouldn't be your average EDF. It's a glider. I plan on taking it up as high as I usually do and shutting off the motor and letting it be a sailplane. If you're planning to fly it in an aerobatic manner, you're not going to shut it off anyway. You're not flying it like a glider anymore.
I'm planning to try it at slope soaring. If it works out OK, I might even remove the Fan.

Cheers,

Peter
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Old Jun 15, 2012, 07:49 PM
Geez That's A Big Fly
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Australia, WA, Parkerville
Joined Sep 2011
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Hey Scott, nice to see you here as well , as you have guessed another Durafly is going to be in my hands and looking forward to it just like the Vampire (which is still flying fantastic)

In respect to the speed of the V70 you only have to look at the manoeuvres it is put through and for me it looks like it will be a hoot and it is not a warbird for me for a change and I can see this being flown more than my Radian Pro.

Shaun.
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Old Jun 15, 2012, 07:53 PM
Geez That's A Big Fly
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Australia, WA, Parkerville
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Originally Posted by phomann View Post
I'm planning to try it at slope soaring. If it works out OK, I might even remove the Fan.

Cheers,

Peter
Pete, why remove the edf, why not just get a sailplane IMHO it kind of defeats the purpose and design of the V70.

Shaun.
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Old Jun 15, 2012, 10:34 PM
WiggleWiggleWiggle
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South Australia
Joined Jan 2008
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Congrats on pushing the envelope Scott. Always good to see something new and interesting.
Just because something looks like a jet doesnt mean it will be faster than something that looks like a glider. The fastest RC planes in the world are actually gliders. I would bet the Zephyr has the potential to be a supremely fast model. Just wondering though why the 3S power system. If it can take a 4000 3S lipo then surely a 3000 4S lipo shouldnt be problem. A 3300kv motor is right in the sweet KV range for a 70mm fan when running on 4S. The lipo wont weigh more so should not affect the models 'balance'. The thing you have to know about EDF's is that they are terribly inefficient. You need double the power of an equivalent prop plane. I eagerly await flight reports as I couldnt get in on this first batch. I gave up reading the discussion on the HK site. There are people there who obviously know nothing about either gliders or EDF's and seem to be caught up in the hype. One of these will be making its way into my hangar as soon as possible. Too cool not to. Any word on when a kit will be available?
Anyway, back to EDF balancing.
I've tried 3 different ways to balance my EDF's and have found the easiest way for me is very straight forward.
Some people remove the impeller and balance it on a prop balancer. This is very tedious and doesnt allow for an out of balance motor. Who's to say the bell on the outrunner your using is balanced. No point going to all the trouble of perfectly balancing your impeller if your motor is not balanced.
I've also tried an EDF balancer machine which I bought but this was also very tedious and due to the technique used of having to constantly remove and refit the impeller, was a pain in the bum.
What I do now is basically feel for a balanced fan. Put on a pair of safety glasses, hold the fan, point the front of it away from you and run it up to somewhere between 1/3 to 1/2 throttle. Try and get a feel for how its running. It will probably have a sort of buzz/vibration feel. I've yet to buy an EDF thats runs smoothly. Then, using a texta, I number the blades from 1 to 5 or however many blades there are. I then cut some electrical tape or masking tape. Using a very sharp blade I cut piece and stick it onto one of the fan blades noting which blade i stuck it too. Then i run the fan up again. It will either get smoother or it will get worse. If it gets smoother then you know your on the right track. If it gets rougher then you remove the tape and move it one blade along. Keep going until you find the blade that gives the smoothest running. Once you find the blade you add a little more tape. If it gets smoother still then you know you are on the right track.If after you add tape it starts to vibrate again then you know you've probably added too much tape and caused it to go out of balance. I hope this helps explain it. Please be careful and always point the fan away from you. Obviously do not do this with VERY high powered fans. Some people have rigs setup for this as holding onto a very high powered fan is very dangerous.
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