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Old Dec 18, 2002, 06:28 AM
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Flying photos

I see there's some inetrest in the Harrier, But is there anyone with New Photo's ? ? ? and has anyone made a electric version of the Harrier. I have seen some really cool engineering here on ezonemag from fellow modelers.
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Old Dec 18, 2002, 10:51 AM
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dave chinnery designed a semi scale non vectored thrust harrier, was a free plan in RCME a couple of years ago, uses a wemotec or Ky fan and a race 600 / ap29l goes quite well and if you ly it into wind, you can get it to hover ! Im building one now. ok its not exactly hi tec nut its vaguely harrier like.

Stu
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Old Dec 18, 2002, 04:29 PM
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St. Louis Intl, Missouri, United States
Joined Jan 1997
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I designed one a few years ago.....standway off scale but it flew pretty good for the time. No thrust vectoring and landed pretty fast. I just liked the way the Harrier looked in the air so I built one.


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Old Dec 19, 2002, 09:05 AM
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Cool

Now that's a Cool little Jet, there even a nice paint job on it.....
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Old Dec 19, 2002, 10:02 AM
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After I turned electric...........My first design was the GR7 harrier which was to be powered by 4 fans. The trouble is that I wanted all 4 to rotate and they would actually form the nozzles on the scale bird. This means either using a small fan, less thrust avalible, or a larger 90mm class fan and a large scale bird. By large I mean around 1:8th or higher so the nozzles dont look ut of scale. If you try and mount the fans in line with the centerline of the plane you need to deflect the air through 90 degrees and you will lose about 50% of the thrust. I was at the stage of preliminary cell/fan/motor calculations when I found information on the X32, X35 JSF fighter. The rest (i hope) will be history.

I'm keeping my 'wet' harrier plans to myself for the moment.

Doc
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Old Dec 19, 2002, 10:16 AM
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United States, PA, Loganville
Joined Feb 2002
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I've been interested in the Harriers ever since I first saw one as a boy. I've been kicking around the idea of building one for some time (since about 1988). I've never liked the idea of IC power, there seem to be less control over the throttle range (very important) and if the engine quits during flight...

The advances in the electric field the last few years have been quite astonishing, and I believe that an electric Harrier capable of VSTOL is quite close to being a reality.

The most important factor/consideration is quite obviously the ducting and the need to "bend" the airflow through the nozzels. The more "aerodynamically clean" the air can me "bent" through the nozzels, the more thrust will be available for VTOL.

From everything I've read on Eric Dainty's Harrier, it isn't truly capable of VTOL or hovering. It seem to be able to take off and land at about a 70 degree angle. While this is a truly remarkable feat, it falls just short of the goals we are all trying to achieve.

I don't have the time and/or money to invest in undertaking the AV-8B project at this time, but I would like to share my design ideas with those who are truly interested in persuing this project.

-Zeke
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Old Dec 19, 2002, 10:29 AM
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Green Lane PA USA
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I think Docs 4 fan idea is pretty slick. You could take 4 small fans that have good static thrust figures, like say the Vasa 55s and make them the nozzels! Use brushless motors, and the new LiPoly cells. Trying to control the thing in a hover would be nearly inpossible though, you would have to just use a forward "Jump" into the air and just bring it in forward. Actual Hover control would probably require a 5th fan for vectored tail control and I dont think the 4 nozzels could produce enough differential quick enough so close togeter to maintain roll stability,,,,.
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Old Dec 19, 2002, 10:35 AM
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Jason, I will let you know about the roll control, its the same design as my X35b. As for hover control, 3 pizo gyros and a few mixeres is all thats needed.

Doc
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Old Dec 19, 2002, 10:59 AM
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Quote:
Originally posted by Doc Watson
Jason, I will let you know about the roll control, its the same design as my X35b. As for hover control, 3 pizo gyros and a few mixeres is all thats needed.

Doc
If you say so Doc
I think I would start with a more stable test platform like a flying X or someting and then see if it could be dialed in. Your teaterd rig hopfully will allow you to dial it in, what is the distance between your two rear fans center to center?
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Old Dec 19, 2002, 11:26 AM
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Oxford, Alabama USA
Joined May 2001
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You guys are amazing!

I'm thinking that Scratch building a B-58, A-10, or F-15 from Blue Foam is adventurous (and time consuming ) but "i aint got nuttin on yous guys!"

Hope it works. However, when it does, I will just quit altogether - it will have all been done!

Like the commercial where the guy gets to the end of the internet!
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Old Dec 20, 2002, 06:09 AM
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Jason, I dont have the plans here at work but the rears are about 200mm apart.

Doc
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Old Dec 20, 2002, 07:39 AM
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Datteln, Germany
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as i know, some years ago Dirk Juras build a Harrier with trust vektoring, has very very short takeoff and landing distance.
it was powered with 4 modified Robbe DF's.

Kerberos
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Old Dec 20, 2002, 12:20 PM
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That would be my angle of attack.
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Old Dec 29, 2002, 03:58 PM
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Bedfordshire UK
Joined Sep 2002
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Ive been reading this thread with great interest. I, like the rest of you have a passion for building a working Harrier. I was fortunate the other week to spend a few hours with a RAF engineer at one of our bases in the uk. I spent ages asking questions as I went over every bit of it. There were four of them in the hanger. I sat in one on the flightline ! how cool is that. Anyway I have been convincing myself this cant be that difficult untill I start reading this thread. You lose how much thrust when you turn the nozells !!!! It almost makes you want to give up before trying. Doc - you've got a lot of patience. Maybe Ill have a go at a flyng bedstead or one of those Muller Flying cars (only joking) I do have a complete mould for a 9th scale Harrier though!! - I think Ill make it a static one. If one of you can come up with a simple motor set up Ill sell you one to put it in.
Maybe the answer is to use 4 of those very small womotec fans on 400 size motors with a foam fusealge and just tilt them with a single servo.??
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Old Dec 29, 2002, 04:29 PM
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Sture Smidt's Avatar
Norge, Østfold, Moss
Joined Jan 2001
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Working Harrier

Suppose the following:

Wemotec Midi Fan 1 off 100g
Brushless with controller 300g
16 cells 1040g
Plane 1000g (fuselage, wing, ducting, landing gear, RC, etc)

Required lift at least 2440 g

Say 20 % contingency lift 488g > total 2928g

Fan efficiency 74 % with inlets (realistic)
Cell voltage 1.0 (optimistic)
Say 10 % losses in the ducting
Say 5 % losses due to thrust vectoring control

The required effect from the batteries will be 2000W or 125A.
The good thing is....you may fly in the dark, it will glow! The top speed will be FAST!

With todays equipment you can hover for a few seconds, with future batteries and motors, who knows. My best guess is that within a few years it will be possible.

Regards
SS
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