Has any one thought about making a Harrier

[Osprey WannaB]

This is a question i just had to ask.. :D
Has Anyone Ever thought about making a Harrier Jump jet??
I realy think this would be a chalange.. but it would be easier to do a conversion then a osprey ect.. I thought About this while flying the harrier in the Pre-Flight Simulator.. Screen shot attached below... :rolleyes: :cool:

[Munkey]

Well if a full size one works it would be possible i guess, but it would be very, very complicated and id think it would cost tens of thousands of dollars for it to work properly and to scale.

[fdr]

A succesful r/c harrier was built and flown by Eric Dainty of the Ottawa R/C club several years ago. It demonstrated vertical takeoff, transition to horizontal flight, and vertical landing at a popular jet rally, so was well documented.

[v22chap]

This guy is doing one with a turbine ,,he has built the whole scale pegasus engine for it and has just this last month or so hovered the test bed version of it .. enjoy
Go down the list of vids to just before other projects and click on

Bedstead for hover vid ..the rest are airplane tests only .
harrier (http://cpl.usc.edu/eschuste/)

[Osprey WannaB]

OKAY, so its been done/is being done.. but wat was the final cost.. i'm thinking if its possible to build a reliable and cost effective harrier for under $5,000. i know the turbines cost a lot.. but just wat about a edf? i realy love designing and creating planes that haven't been flown in rc.. but the thing is i never know if it has been done or not:D
JAMIE

[v22chap]

.60 size ducted fan has been done by Eric Dainte ....and turbine is being done . The turbine alone is going to cost almost the 5000.00 .... funfly /fanfold is still open ... ;) :D ....and it would be a little softer on the pocket.Try EDF on fanfold.

[Lewist]

A full scale harrier using exact scale control systems i think at this time would be hard to do with EDF, but NOT impossible.

I am thinking about making a scale f35 (i think thats the one) the JSF. I think that would be a better start for EDF, only one set of puffer jets to substitute!

[mandrin13]

Ill try to make one if anyone has some spare parts lying around,like recievers,speed controls,edf's,etc.I have lots of fome.

[Guille]

I remember one which was publicxated in Model Airplane News about 8 yrs ago in the last page. ¡¡¡worked!!!

[Lewist]

I just don't think there is enough separation to get good control.

I used to think that an EDF in each nozzle would work, but since I made my EDF VTOL hovering rig i have realised that there is not really enough separation between the nozzles to get good control..... (if it were possible i think that the full size harrier would be setup that way.. much easier than puffer jets!)

[norite]

Yes, I think it would work with EDF. It's a thought project of mine that I mull over in my idle hours. I don't know if I'de ever find time to try and build one myself though...! it would make for a very challenging project.
You'd need a big fan with plenty of thrust - I've seen one claiming up to 20N of thrust.
The four nozzles and fan would be enclosed in a heat shaped and sealed plastic bottle end. Puffers to each wing tip could be attached to this "bottle", and made to rotate through 90 degrees, from vertical to horizontal, in tune with the nozzles as the transition from VTOL to regular flight happens. the piping would have to have some sort of sleeve mechanism to allow them to rotate. They could also be operated off a separate servo, but connected to the servo controlling the nozzles via a Y-lead. You'd also need a gyro to control the amount of thrust going through the wingtip puffers in order to stabilise the harrier - If you didn't, and if one wing goes up beyond a critical angle, it'll just flip over onto its back and you'd have no way to recover.
The really crital thing would be the power to weight ratio; generating enough thust to hover for long enough and without burning out the li-polys and/or motor.

[flyboy367]

i cant see it being that hard. central fan, overpowered of course. run 2 ducts one to each wingtip just like th real thing. then your 4 nozzels all connected to a flap servo so you can use the control knob to set the thrust angle. have retracts and flaps on the same channel so when you got to vtol its like the real thing, gear down, flaps down. just get a base harrier aircraft. and follow pictures of the real system.

[maumarti]

hi
I have built one of it. (Byron ducted fan - Rossi 108 engine)
you see www.mauriziomartinucci.com
in the section "modelli a miscela"
hi
maurizio - ITALY

[norite]

very cool. the video is very interesting! Do you haveany other videos of your harrier hovering?

[norite]

I've come across this (http://www.shredair.com/fan.html) website selling high power EDFs. So it seems getting the amount of thrust to hover is there, the main challenge will be getting it to hover without tipping over. Damn, I'm getting interested in this, perhaps I should build a hovering test bed based on one of these EDFs!! :rolleyes:

Something else I've thought about - if the four nozzles are angled outwards slightly, this might make it more stable in the hover.

[v22chap]

I doubt that the angle will help much ,,if it did the full scale would have done it I'm thinking. :D
R/C VTOL is really hard ,,because of the weight to power ratio's that we work with .If you are going to go a little "un" scale ,,,I would vote for making the fuse and ducts a little wider than scale or maybe mini fans in the wing tips and tail for control.
Keep us in the loop norite
Larry

[maumarti]

No, sorry...I don't have other video of the "event".
After little time I have destroyed the motor.... :-(
and I have abandoned the development of the project.
It has flown with success in traditional mode: in hovering it was enough controllable.
Hi
maurizio - ITALIA
www.mauriziomartinucci.com

[norite]

According to shredair.com, the most powerful edf can generate up to 18lbs of thrust. I bet this is static, and even optimistic, but it's a lot of poke for a fan unit weighing 115grams and having a diameter of 115mm. the 90mm fan (weighs 48g fibre glass wighs 64grams) can generate 8lbs of thrust.....! :eek:

[ronmeister]

Wow shredair.com has got a edf producing 19 lbs of thrust!
http://shredair.com/fan.html
Although, to produce that, you would have to have a crazy expensive motor, esc, and batteries.

[norite]

yeah, amazing, eh?!....but look at the price tags. the motor and fan unit alone will set me back several hundred quid.....

With all that thrust, I'm sure it would be possible to duct some of it away to the wingtips for pufferjets, and still have enough left for hovering.

<Waits for several thousand £££ to fall out of the sky....> :rolleyes:

[vampire67]

According to shredair.com, the most powerful edf can generate up to 18lbs of thrust. I bet this is static, and even optimistic, but it's a lot of poke for a fan unit weighing 115grams and having a diameter of 115mm. the 90mm fan (weighs 48g fibre glass wighs 64grams) can generate 8lbs of thrust.....! :eek:
Optimistic view :cool:

How about motor, battery and frame weight.
You will also need to compensate for losses >50% in hover mode for the ducting and thrust deflection.

The first EDF Harrier may be the one Dirk Juras documents in the german EDF bible "Das Elektro Impeller Buch" (The EDF Book) from 1997.
It was designed around 4 Rojet powered by 4x Speed 480 Race and 10x1700SRC. Weight was documented around 2600g at ~1100g thrust. With the maximum thrust defection of 60° the thrust droped to ~850g. Size was 1,75m length and 1,3m wingspan.

So with decent fans and LiPo it should be possible to hover.
However the extent of such a project needs some top notch EDF background to be successfull.
Beside the stability control the ducting allowing for the thrust vectoring requires a lot of know how and craftmanship. As thrust losses of up to 50% need to be compensated the trust/weigt ratio need to be rather 2:1 than 1:1 for successfull hovering.

Daniels fans are around already for >5 years (at least the 69 and 90mm) and are still defining the target performance ANY competion is compared to. So the sudden discovery of this "new" fans by you just tell me you should spend some more time "mulling" over this before spending the investments ;)

Last but not least, EDF is not about presure but airflow. So making a big "plastic bottle" powerd by a single fan and just adding thrust vectored outlets is not the way this will work.
You need to invest into some clever ducting guiding the EDF output flow without much area and angle change to the vectored thrust outlets.
Daniels fans are also rather built for top speed (so are most EDF). For a Harrier we may need a fan with different charateristic, maybe less speed, more presure. In that situation your "plastic bottle" may become usable again.

kind regards Peter

[norite]

some nice comments for thought there, Peter.
You are correct, this is something that requires a LOT of careful research first. But at some point someone is just going to have to take the bull by the horns, jump in and go for it. :) :D

As for the plastic bottle, what I was trying to get at was taking a cylindrical bottle and heat shaping it to look like the real Rolls Royce Pegasus engine and nozzles as it is in the real Harrier, a la:

http://www.aircraftenginedesign.com/pictures/Pegasus.gif

http://www.harrier.org.uk/history/images/Figs_7_Engine_gas_flow.jpg

Or, building a shape out of wood and heat shrinking plastic over it.

Someone has already built a Harrier, but powered by a jet turbine, and it works. I have a video of a test bed in hover mode.
For a thrust/weight ration of 2:1 a you mentioned, lets see, an EDF generating 4kgs of thrust for a model weighing 2kg.....or 6kg for a 3kg model. A bigger model would be more stable in hover mode, but it would also be heavier. :cool:

[norite]

A quick comment on the second diagram...
I can see immediate problems with this design in an EDF format - you would have to make sure the thrust is distributed evenly between the front and rear nozzles, and not all pushed to the rear nozzles.

anyway, it's late and I've got some sheep to count! :p

[vampire67]

I personally don't belive the Pegasus engine can be copied to EDF 1:1.
Turbines produce presure. EDF is mostly about volumetric flow.
So the flow seperation to 4 nozzles doesnt work the same way as in the shematic.
For EDF you would need the same flow directors that the Pegasus engine shematic shows in each nozzle also for the seperation.
The thrust control could then be made with some valiable flow dividers directing a different percentage of the source flow into each nozzle.

Dirk Juras solution was using 4 seperate fans. This way he overcame the ducting problem.

Regarding thust figure: 2:1 is the netto thrust for the design point not the resulting thrust in hover mode (which should be a little over 1:1).
2:1 will be difficult to reach. The actual top EDF performers are in the 1,3..1,5:1 range. Of couse designed for a little longer engine run time.
You may have to desin it for 2..3min run time only. The problem with short run time is the resulting battery load which will be realy in the 20C region.

kind regards Peter

[flyboy367]

i think it can be done. im thinking very light fiberglass chassis and a big brushless motor set back about 3" from the fan, this way it doesnt block the duct and air will pass on either side for cooling. then you just need to seal the engine compartment up so pressure stays the same, but here is the kick. the real harrier has vent outlets. one on each wingtip and one on the nose and tail. this helps stabilize the aircraft. i think making that work would be more difficult then building a pegasus.

[vampire67]

i think it can be done. im thinking very light fiberglass chassis and a big brushless motor set back about 3" from the fan, this way it doesnt block the duct and air will pass on either side for cooling. then you just need to seal the engine compartment up so pressure stays the same, but here is the kick. the real harrier has vent outlets. one on each wingtip and one on the nose and tail. this helps stabilize the aircraft. i think making that work would be more difficult then building a pegasus.
EDF is not about preasure but airflow.
If you built up backpressure behind the fan the fan starts stalling and you will have huge losses.
So you need to guide the airflow when you want to deflect it more than a few degrees.
In the Pegasus shematic you see some flow guiding aplied in each nozzle..

You would need some similar guiding devices to split the flow from a central fan to the four nozzles.
If this guiding is made variable with some servo you may also use it for controlling the thrust level of each nozzle.

The EDF itself will then need to be completely designed with high presure but low flow in mind.
None of the commercial ones is designed for this.
Daniel Schüblers design is also very specific for high eflux. So they will not realy work in 1:1 Pegasus design.

kind regards Peter

[nabiul]

Does any one know how the joint strike fighter stabalizes itself? The fan for vertical lift isnt centered on the plane making me think that thrust from the back is directed downwards for stabilization.

[rdresch]

Exactly correct. In hover the tailpipe turns down 90 degrees deflecting hot gases downward.
Rudy

[Lewist]

and it uses puffer jets in the wings to control roll!

[QUANTUMPHYSICS]

Somebody needs to design a VTOL Harrier with EDF's. It needs to be relatively small, and controllable like a electric r/c helicopter. That or a VTOL F-35 JSF would be the coolest toy ever made. I'd gladly spend $500 on one.

[emreozcakmak]

ı dont wat to be a optimistic one , ı m not a experienced one.And if it works ı would be the one who gets happiest.but it is a fantasy.

[Terry S]

Sad but True :(

Terry

[bentwing]

check this thread out,It goes back nearly 2 years. I dont know if he ever got it to vtol , it might give you an idea of what your up against using a edfhttp://www.rcgroups.com/forums/showthread.php?t=271994

[Lewist]

that harrier was never designed to vtol, it was just a scale flying model not a hover model!

give me £10,000 and i will give you one scale vtol harrier.. I would go and do it now, but i don't have the cash to purchase all the bits.

the only bit which is a limiting factor is the puffer jet system, and all we need for that is a medium flow medium pressure air supply. weather that be a ducted fan with a compressor type blade setup (al-la jet engine) or a centrifugal device, or a roots or screw type blower. but one of these will work, its just the time and money required to sort out which one will! (then make it light or course!!)

you can nock up an EDF hovering vtol platform very very easily. mine worked first time round! and took a total of about 3 hours build time.

[emreozcakmak]

İt can hover ı agree this.But Harrier as a special plane has the specialities as all we know like giving out propulsion from its wings roots and ends.
We all see hovering rc ' s.And we would like to see your vtol plane in the Harrier 's body.
With some little disabilities.Take care Wish luck. :)

[flyboy367]

just thinking here but that sodabottle mentioned before. looking at the pegusus drawing again im seeing 2 sets of turbines. lets say for the sake of rc not so scale the "bottle" with 2 edf's in it? then you could focus volume down the first nozzels with some air flowing to the second fan to be multiplied and sent out the back 2. im no enginerr i only play on on the internet but maybe some of you guys that are more handy at this could give it a go. heck if i knew the materials to do it with i have 2 edf55's with brushed 300 motors sitting in my truck.

[MeGrimm]

Check this thread out:

http://www.rcgroups.com/forums/showthread.php?t=520712

It kinda covers this topic in great detail, including from the EDF point of view.

I personally believe that it's very possible to build an EDF Harrier, and not neccessarily all that expensively, and I have huge respect for those trying to do it. If I had the circumstances I'd be building my own version right now! ;)

All the best

[Jango.]

I found a website that offers about a $3000 dollar harrier at www.excitingrcm.equology.com

[v22chap]

Notice that they don't show a picture of the bird or have videos of it flying !!!!!!
This has been around for several yrs and I think it is just a test to see if the interest is there for a model that "THEY" would like to produce.

[Jango.]

yeah i know but what if they do sell it and it works

[rdresch]

note that the date of the page is 2002. Don't hold your breath. I won't be an investor.
Rudy

[nexstar]

I think the whole harrier idea would work. the autogyros, and motors would just have to be placed in the right positions to give the right amount of stability, and control over the aircraft. it would be a long slow, tediuce process. but it could work.

[Evil Lord X]

Here is something I found (and saved) years ago while drooling over model jet engines. I have no idea where I found it...

[v22chap]

I know where it is and when I get home I can give you the url ,,, he now has the engine running and in a flying bedstead style config on a teather and a video showing it hovering .

[v22chap]

Here is the link to the harrier by Ewald Schuster
scroll down to the bottom of the video section to bedstead for the hovering test video.
He also has harrier fuse that he is flying in just airplane mode with some great vids of it.
enjoy

Harrier (http://cpl.usc.edu/eschuste/)

[xstanbx]

Can't remember where I got this file, but it is a video of a model Harrier taking off vertically, transitioning to forward flight, then landing vertically. It is very impressive......
See this link:
http://www.rcgroups.com/forums/showthread.php?t=581512#post6203466
r/

[avianaut]

Isn't it great what ya can do with an R/C flight sim these days! :rolleyes:

Cheers.

[Harrier_Flklnds]

What about converting a 1/72 or 1/48 or 1/24 scale plastic kit with a ducted fan engine.
With micro servos as nozzle rotaters.

[norite]

What about converting a 1/72 or 1/48 or 1/24 scale plastic kit with a ducted fan engine.
With micro servos as nozzle rotaters.

I think they would be too heavy. It's best to use balsa or depron. The power to weight ratio is absolutely critical here and you'd be looking to keep the weight down as much as posible...
It would be possible to use a single servo for the nozzles, using the channel normally reserved for the flaps so the transition from vertical to horizontal flight could be carefully controlled by way of a dial on the transmitter.

[Psionic001]

Hiya,

has anyone made any progress in this area. I'm looking at rekindling my harrier bedstead build soon.
http://www.rcgroups.com/forums/showthread.php?t=520712.

I just need to do some refinement on the reaction control ducts and get a decent gyro.

If anyone has an unused 90mm fan and/or some hacker motors and/or some good gyros they can donate, then PM me or shout out here.


Thanks

Psi

[Doc Watson]

F35b vtol..........

www.awatson1.fsnet.co.uk


I designed a harrier in the 90's using an OS 91VRDF linked to a Viojett fan, losses of 50% of thrust are to be expected when turning air through 90 degrees.

4 micro fans which rotate and act as nozzles might work but weight is always the enemy......

Doc Watson

[Psionic001]

Thanks DW,

some really great info on your site.

My losses are nowhere near 50%.
Do you have any other pictures of the ducting that you designed? From what I saw, the 3 stage tail nozle, was 3 seperate strait tubes which had a sharp inner bend. I also saw no round lip on the fan units.

The round lip alone gave me back about 20% thrust from inlet loss that I experienced.

Do you think you'll continue with this project?

Thanks

Psi



F35b vtol..........

www.awatson1.fsnet.co.uk


I designed a harrier in the 90's using an OS 91VRDF linked to a Viojett fan, losses of 50% of thrust are to be expected when turning air through 90 degrees.

4 micro fans which rotate and act as nozzles might work but weight is always the enemy......

Doc Watson

[Doc Watson]

No I wont continue with the harrier for the moment.... its taken 6 years to get this far with the f35b.... although I do get sidetracked for months/years on other projects.....

I had all the harrier drawn up in corel draw somewhere..... will see if I still have it around on a disc somewhere.

Andy

[Psionic001]

I have some partial drawing of the harrier wing drawn up from tracing, but any extra drawing would be great.

I have a feeling I'll end up going to a 120mm fan before the 90mm fan. The thrust ratio is just not going to allow me to carry a fuselage with the $$ I have available to complete the project.

best regards

Psi

No I wont continue with the harrier for the moment.... its taken 6 years to get this far with the f35b.... although I do get sidetracked for months/years on other projects.....

I had all the harrier drawn up in corel draw somewhere..... will see if I still have it around on a disc somewhere.

Andy

[likai]

I'm working on a turbine version AV-8B with puff-air control.

[Psionic001]

That outlet ducting looks great!

Will you be using 2 turbines? (Front/back)

I've done my bleed air from the back centre of the outlet duct. I think that's what you've done too.

Psi

I'm working on a turbine version AV-8B with puff-air control.

[likai]

That outlet ducting looks great!

Will you be using 2 turbines? (Front/back)

I've done my bleed air from the back centre of the outlet duct. I think that's what you've done too.

Psi
I use single P-180 turbine and locate hot-gas nozzle foreward slightly just on the C.G. and move cold-air nozzle foreward too. The cold-air nozzle is dummy and for scale look only.

[JSAMVTOL]

nicely done!! ;)

how much thrust do you lose from splitting the nozzles and vectoring?

i hear anyway from 20-50% or more from others. but what is the loss with your turbine setup and how do you measure statis thrust loss from vectoring?

thanks
js

[JSAMVTOL]

nicely done!! ;)

how much thrust do you lose from splitting the nozzles and vectoring?

i hear anyway from 20-50% or more from others. but what is the loss with your turbine setup and how do you measure statis thrust loss from vectoring?

thanks
js

[killzone]

Im new to this site, but i saw the harrier and had to know about it, ive seen the pictures taken and wanted to know if it works like the real one. ive always wanted to built a rc harrier because there isnt one like it yet, but you bet me to it :[ hehe oh well, nice one, see i like a challenge, first i started off flying rc helicopters which is great but then ive always loved harrier's so thats what gave me the idea. anyway thanks for your time. hope ya get back

[Geoff Woodward]

You have heard of Eric Dainty , havnt you , at the Bay of Quinte Jet Rally

[Geoff Woodward]

7lb Harrier with fuel ,OS91, High Nitro ,Byron fan 3min flight , flew in bad weather, with crosswind about 95 or 96 , year that is
4 years flying experience , seemed to drop out of modelling , not widely publisized
Good hover , transition and hover land, lots of people saw it,,,, that design with EDF shold be easy , electric has good power , see those 6000 watt 140 MPH model boats
No outside props or suchlike , looks exact Harrier or even gyro
Find this guy , Where is Eric Dainty , he must be a Genius

[Mr.Me]

i would make an EDF one if i had the money to...

Regards,

Nick

[likai]

I just install nose and main gear on the fuselage and made some falling test. :D
http://video.google.com/videoplay?docid=1466301086416552880

[heli_madken]

Looks fantastic, be great if it flies as well as your EDF VTOL, how much of the technology you used for the EDF VTOL will you transfer to the Harrier, would you consider using low profile EDF units in the wings for instance (I know it wouldnt be scale, but it would help hover) rather than relying on puffer jets?

[Brandano]

I think one solution for the puffer jets that could be considered is to have an outrunner drive a centrifugal blower from where to spill the air for the puffers (and for the cooling of the motor itself). This would move a smaller volume of air compared to a ducted fan, but at a higher pressure. Rather than using a small round tube in the wings I'd have the air move down the wings through box shaped spars, to allow for a larger surface, and shape the ejectors so that they would drag outside air with them the same way a pressure driven vacuum pump works. Using a single source for the control air means that each control valve will need to be controlled by its own servo. Maybe the roll puffers and the pitch puffers could be driven by a servo per pair,but the possibility to open or close all while the main motor is trimmed for hover might be a bonus for fine control in landing

[helidude2]

i was just consitering desining a herrier so i googled it so and beheld i ended up here and i think i want to build a small 30-40 in fiber glass model the hard part will be cg

[helidude2]

onsecond thought im going with an f-35