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Old Apr 01, 2012, 06:59 PM
6 months to finish a rtf
pulsery2k1's Avatar
upstate ny
Joined Jun 2003
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Help!
Vertical take off and landing edf jet

Hi .

Question:

I'm think about building a vertical take off and landing edf Jet

but unlike a harrier or f-35 , I 'm thinking about using 4 of these new
20 blade 55 mm edf units in a model sort of like a quad copter.

being an airplane guy ,I saw one of these quad copter fly and thought
this could work 4 of these units would produce 4.5 lbs of thrust in a
3 lb model . the model would take off vertical then the units would
rotate for foward flight .

so the question is would the stabalization unit from one of these
quad copters work for this.?
and were can you purchase just the unit. ?

next question on the quad copter the motor and props and fairly
far apart - bringing the units in closer - is this possable ?

video of 20 blade edf in a edf jet , it gives the model excellent vertical
20 BLADE EDF TEST FLIGHT.wmv (4 min 47 sec)
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Old Apr 01, 2012, 07:31 PM
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Quote:
Originally Posted by pulsery2k1 View Post
...I saw one of these quad copter fly and thought
this could work 4 of these units would produce 4.5 lbs of thrust in a
3 lb model ...
It can be done but your flight time will be very short. You might be able to go around once or twice before you have to land.

It's about thrust and the amps that you eat up while making that thrust.
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Old Apr 01, 2012, 07:52 PM
6 months to finish a rtf
pulsery2k1's Avatar
upstate ny
Joined Jun 2003
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RCvertt

Thanks for your reply , I do relize the power it will take to lift off
but with a winged jet once in normal flight , flying on the wing
power would drop to acceptable levels.

what I 'm worried about is control with the fans close together
during vertical takeoff . even the real harrier is very hard to
fly during this part of flight.

the other is the transision to normal flight control from the
vertical flight ?
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Old Apr 01, 2012, 08:39 PM
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Quote:
Originally Posted by pulsery2k1 View Post
...once in normal flight , flying on the wing power would drop to acceptable levels.
But the weight of the three extra EDF units and the weight of the extra batteries won't. Means you'll have to fly faster than normal to stay in the air and you'll use more power while doing so than normal.

Quote:
Originally Posted by pulsery2k1 View Post
what I 'm worried about is control with the fans close together during vertical takeoff . even the real harrier is very hard to fly during this part of flight.
The farther out they are, the more stable it will be but it all depends on what the purpose of your aircraft is. If you don't have to do a lot of hovering for very long and don't have to fly in much wind then close together might be acceptable.

Quote:
Originally Posted by pulsery2k1 View Post
the other is the transision to normal flight control from the vertical flight ?
Vertical to forward flight is easy. Forward flight to hovering is little more tricky due to the turbulance of the airframe while slowing down. You also have to be a good enough pilot to control the aircraft if it's not facing directly away from you.
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Old Apr 02, 2012, 12:03 PM
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Quote:
Originally Posted by pulsery2k1 View Post
I'm think about building a vertical take off and landing edf Jet
but unlike a harrier or f-35 , I 'm thinking about using 4 of these new 20 blade 55 mm edf units in a model sort of like a quad copter.
Have a look here:

http://www.rcgroups.com/forums/showthread.php?t=1348077

Unlike a quadcopter you will need thrust vectoring for sufficient yaw control and to counteract EDF-torque. The example above uses control vanes on the front and aft fan. Another option is tilting the whole EDF-unit.

Can you post some performance details of these EDFs? Especially thrust vs. wattage would be of interest.
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Old Apr 02, 2012, 03:50 PM
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cool wer'd u get 1 ?
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Old Apr 02, 2012, 08:03 PM
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pulsery2k1's Avatar
upstate ny
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VTOLicious/RCvertt

thanks , the video seem to show what I'm thinking will work.

now to readup and build a my own quad edf.

VTOLicious

the 55mm 20 blade give 504 grams stacic thrust at approx 22 amps
on a 1000 ma 3s lipo . in the video you can see the model goes
vertical just letting it out of my hand
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Old Apr 02, 2012, 11:14 PM
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Quote:
Originally Posted by pulsery2k1 View Post
... the 55mm 20 blade give 504 grams stacic thrust at approx 22 amps on a 1000 ma 3s lipo .
How long is your flight time with this set up?

It's a very nice looking unit.
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Old Apr 03, 2012, 09:11 AM
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RCvertt

the 504 gram and 22 amp's are full throttle , the model fly's
very nicly at half throttle so my timer is set to 4 mins and
lands with 30-40 % left in battery


as to were I got it = I sent a pm
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Old Apr 03, 2012, 01:51 PM
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Quote:
Originally Posted by pulsery2k1 View Post
RCvertt

the 504 gram and 22 amp's are full throttle , the model fly's
very nicly at half throttle so my timer is set to 4 mins and
lands with 30-40 % left in battery
That sound pretty good to me. The unit looks a lot better than most with all those blades also.
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Old Apr 03, 2012, 02:48 PM
ich bauen groß modell flugzeug
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i din't get the PM
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Old Apr 04, 2012, 05:27 PM
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I bet it could be good for one of these, or maybe a harrier with two units in line with each other where the front fan fed the front nozzles and the rear fan fed the rear nozzles.

MVI_1832.AVI (0 min 22 sec)
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Old Apr 04, 2012, 09:38 PM
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pulsery2k1's Avatar
upstate ny
Joined Jun 2003
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RCvertt

Thanks alot with this video and the one from VTOLicious
I can see this will be a challange . as each seemed to be
controlled diffrent ways the first with gyro's the second
fan speed control ? both were no where as smooth as
a quad copter.

I know that the real harrier uses bled air at the wing tip's
nose and tail to hover ,takeoff and land - but isn't easy to
fly - very high accident rate .

one answer may be to use a main fan for vertical and four
computer/gyro control smaller thursters.

but thank's the video's have been a great help .
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Old Apr 05, 2012, 12:01 AM
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Quote:
Originally Posted by pulsery2k1 View Post
both were no where as smooth as
a quad copter.
True. The harrier would be more like the first video if it used a MultiWii instead of GWS-PG03 gyros but still not as good as a quad. The thrust area to wing area is wrong for a very stable hover in slight wind. That's why helicopters are great in wind. Nothing but thrust area and basically no surface area for wind to hit.
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Old May 10, 2012, 09:43 PM
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Quote:
Originally Posted by pulsery2k1 View Post
RCvertt

the 504 gram and 22 amp's are full throttle , the model fly's
very nicly at half throttle so my timer is set to 4 mins and
lands with 30-40 % left in battery


as to were I got it = I sent a pm
plz send me a pm!!!

quadcopters use 2 counter rotating props....is there a counter rotation version of this?!?
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