Twin boom pusher

[Crash Pilot]

Gents

I am looking for a twin boom pusher to use as my next platform.
Does anyone know of an affordable kit that can be purchased.

The second option would be an affordable flying wing that could hold a 1 pound payload.

The flight characterics are important because I will be using a RCAP .

I have search but come up empty handed.

Any help would be greatly appreciated.

Crash Pilot

[Brandon Crash]

You have my attention now as well, as I am looking for something similar.

I have seen "Big Brother" mentioned a few times, but have yet to find it, as I believe it is a free plan.

I was wondering about an Aerosonde lookalike. I saw a guy with a 1:1 scale pss version in the UK....

Brandon Oram.

[Connexxion]

I'll be also keeping an eye on this thread as I'm also looking for a similar bird.

[Brandon Crash]

well I guess that it could really become a world wide effort then, where are you Connexxion? I'm in the UK, and Crash Pilot is in Oz.....

[Wmacky]

There seems to be quite a shortage of inexpensive ARF Twin boom UAV style airframes.



Something like this mono fuse would be cool too!

Click on the movie labeled "LEARS"

http://www.boschaero.com/movies.htm

[RaptorAP]

Maybe I should ARF mine, since there seems to be a shortage. I dunno, Its not very aerodynamically designed,
flies great though.

[kd7ost]

There are a few around, but all that I'm aware of are scratch built and home designed. Here's mine.

Dan

[dalbert02]

Add me to the list. I really like the looks of the one by rpflightsystems. I would love to build Dan's. And Raptors looks like it can do the job very well. I can build a kit but I am not comfortable scratch building my own design that will have thousands of dollars of equipment in her. Any of you guys interested in selling plans?
-dave

[kd7ost]

I don't have complete enough plans to justify a sale.
I drafted some parts fairly well, but other parts I just
built and fit as I went along.

Dan

[Crash Pilot]

Guys

Looking at the reponses there is a large demand for a twin boom pusher.

It would be a good oportunity $$ for someone with a full set of plans or that could produce a reasonably priced kit.


Crash Pilot

[Gary Mortimer]

Make it a SPAD and I'll be in.

Maybe a group airframe thats used around the world.

Add an RCAP and all the new extras an a community UAV is born!

G

[Connexxion]

well I guess that it could really become a world wide effort then, where are you Connexxion? I'm in the UK, and Crash Pilot is in Oz.....

I'm in the Netherlands.

I just found this company,but couldn't find any prices:

http://www.rpflightsystems.com/conventional.htm

Looks good.

[Crash Pilot]

Connexxion


They look like a great airframe but they are out of my price range.

They sell the complete setup and not just the airframe.

I feel they are mainly targeting the commercial market and not your average hobby flyer.

I have received quotes from them.

Crash Pilot

[Connexxion]

Seems we've to look further.

Hope some company is following this thread and will decide to build an ARF twinboom pusher. ;)

[Peter Seddon]

Excuse my ignorance but why is the twin boom layout so popular for UAV models?

Peter

[s2e3s2z2]

I would be interested in a twin boom design like these should an ARF kit become available. Some personal preferences would include a 60"-70" wingspan and an AUW of at least 55 - 65 oz.

[Connexxion]

Excuse my ignorance but why is the twin boom layout so popular for UAV models?

Peter

Because these types of birds have a prop on the back instead on the nose.

It's much easier to take pictures if there's no propellor swingin' in front of your camera.

Since the engine is at the back of the plane,you got plenty of room for payloads in the nose.

You also can keep a reasonable distance between the engine and the rx.


And,of course,it just looks cool!

[toxicmouse]

check:

http://www.alshobbies.com/shop/lookupstock.php?pc=7069&Desc=&PHPSESSID=e1fdd948d81d437292f9e546413dbad4

it may not look cool or dangerous but it seems to have loads of space.

[d_wheel]

I prefer a single boom design as it is easier to assemble/disassemble/transport. However, if someone comes up with a 2.5 to 2.75 meter wingspan twin boom design with two piece wing then count me in!

Later;

D.W.

[typicalaimster]

How big do you want? Don't tell me wingspan! More like how much equipment do you want to take up? Do you want Wet or Electric as fuel?

I've done two twin booms over the past year. One of which is still in production as a FPV trainer. I'm currently working on revisions for one of the planes. Although it's geared more toward FPV the new revision has enough room in it for some UAV equipment.

To answer d_wheel.. I've done a 1.5 meter collapsible system. The whole thing could fold down into two 30x15x15 boxes.

[kd7ost]

Single booms are good too. I've recently designed and built one of those. It's smaller than my twin boom and is electric powered instead of gas. Same story on plans but I did do an extensive build thread on it here. It might be helpful.

Dan

http://www.rcgroups.com/forums/showthread.php?t=573747

I knew you would ring in when you saw this Scott. ;)

[d_wheel]

How big do you want? Don't tell me wingspan! More like how much equipment do you want to take up? Do you want Wet or Electric as fuel?

I've done two twin booms over the past year. One of which is still in production as a FPV trainer. I'm currently working on revisions for one of the planes. Although it's geared more toward FPV the new revision has enough room in it for some UAV equipment.

A payload of at least 7.5 pounds, but the most important part for me is it must be big enough to be easily seen at 1/4 mile or so distance, up about 800 feet. That's why I want something at least 2.5 meter wingspan. I would prefer gasoline powered because charge times are just too long on the big battery packs. No V tail because that requires mixing. Plain and simple is better IMHO.

Later;

D.W.

[d_wheel]

Single booms are good too. I've recently designed and built one of those. It's smaller than my twin boom and is electric powered instead of gas. Same story on plans but I did do an extensive build thread on it here. It might be helpful.

Dan

http://www.rcgroups.com/forums/showthread.php?t=573747

I knew you would ring in when you saw this Scott. ;)

Yes, I saw that. Gave me some ideas of how to design one. Looks neat and simple. The simpler the better.

Later;

D.W.

[Connexxion]

check:

http://www.alshobbies.com/shop/lookupstock.php?pc=7069&Desc=&PHPSESSID=e1fdd948d81d437292f9e546413dbad4

it may not look cool or dangerous but it seems to have loads of space.

It still has an engine in the front.And there's no much room left for the equipment for so far as I kan see.

[Medve]

if you go to steelheadproducts.com and order two E-Panther or Push Panther kits, you'd have 90% of the work done for you. All you have to do is choose how you want to connect the wing sections, and attach the fuses and tail.

[macboffin]

I don't wish to sound superior or condescending, but why don't you guys who like the idea of twin boom pushers buy some balsa and start bashing it into shape? It's hardly rocket science! Even easier with foam. Start by making some small balsa or foam sheet chuck gliders as scale models and experiment.Hinge the control surfaces with thin ali foil, try bending them and see if you get enough elevator/elevator/flap response.if a little one is ok then a bigger version will be better.

[typicalaimster]

I don't wish to sound superior or condescending, but why don't you guys who like the idea of twin boom pushers buy some balsa and start bashing it into shape? It's hardly rocket science! Even easier with foam. Start by making some small balsa or foam sheet chuck gliders as scale models and experiment.

Actually funny thing. I start with Foam Bluecore to see how it responds. I then scale it up to about a '10' sized plane and work it from there. You are right it's not rocket science.

[s2e3s2z2]

Someone had posted a link in another thread to a website that allows one to configure an airplane to their own personal preferences. It had the option of adding a second boom or extending the fuse etc.. Alas, I can't seem to find that thread at the moment.

[Brandon Crash]

I am up for bashing, and indeed plan to do so, I was chirping in in case someone had a decent plan to start from, I am keen on the idea of a community plan/project, as it can add to the fun. I am not really in the market for an ARTF, unless it comes in for less than I can build it for. with ARTF it is usual to require mods to suit your needs.

I am a big fan of Ira's Shot getter, and hope throw one together.

As for the twin boom pusher, I like it. I saw one as a kid ( dave chinery's E400) and ever since have liked it. Couple that with then seeing the Aerosonde back in the 90's, and I'm sold, but it has to have the inverted V. :o

What can I say? It tickles my fancy.

we all have our foibles.

[macboffin]

I am up for bashing, and indeed plan to do so, I was chirping in in case someone had a decent plan to start from, I am keen on the idea of a community plan/project, as it can add to the fun. I am not really in the market for an ARTF, unless it comes in for less than I can build it for. with ARTF it is usual to require mods to suit your needs.

I am a big fan of Ira's Shot getter, and hope throw one together.

As for the twin boom pusher, I like it. I saw one as a kid ( dave chinery's E400) and ever since have liked it. Couple that with then seeing the Aerosonde back in the 90's, and I'm sold, but it has to have the inverted V. :o

What can I say? It tickles my fancy.

we all have our foibles. Inverted Vee tailplanes lead to some interesting complications at the top of the vee as regards the two surfaces not clashing with each other ; there has to be a "plain" section there to allow swinging space. Just right for the glass reinforcement area though.

[macboffin]

The "Bobcat" is a sexy looking design shape that lends itself to your purpose.
Might as well look good as well flying ok! Design would scale nicely.

[Itzik Ronen]

sorry

[Ninjak2k]

Connexxion


They look like a great airframe but they are out of my price range.

They sell the complete setup and not just the airframe.

Crash Pilot

Crash,

What were their quotes?


I've done two twin booms over the past year. One of which is still in production as a FPV trainer. I'm currently working on revisions for one of the planes. Although it's geared more toward FPV the new revision has enough room in it for some UAV equipment.


Typical,

Are those guys available as plans, kits, or ARFs anywhere, or where these commercial applications?

Thanks,
Dan

[Ninjak2k]

Dan and Raptor, love those planes! Even some sketches would be nice.

~Dan

[Crash Pilot]

Guys

I would be up for a modular design that would fit in a large suitcase.

I would love to see a building thread.

If nothing comes out of this I might look at a trainer and modify the front and cut the rear off and install a firewall and twin boom. Also modify the wing to be in two parts.


Crash Pilot

[macboffin]

Guys

I would be up for a modular design that would fit in a large suitcase.

I would love to see a building thread.

If nothing comes out of this I might look at a trainer and modify the front and cut the rear off and install a firewall and twin boom. Also modify the wing to be in two parts.


Crash Pilot Good way to go!

[Vince53]

How about a twin engine as in Bruce Tharpe's Super Flyin' King?

[Crash Pilot]

Guy


Found this drawing.

Crash Pilot

[Connexxion]

Nice pic,who's gonna built it for us? :D

[Crash Pilot]

Good question.
Need someone with a lazar cutter

[Connexxion]

Maybe we should contact several chinese modelplane manufacturers.

I sent a few days ago a mail to one.No reply yet.

To build self one will take to much money for the equipment and to much time which I prefer to use for integration and development of the electronics.

[red_gol]

Hi, I'm in Beijing and we have a rc club. My friends and I am also interested in UAV. And we have our local made plane and auto-pilot. Below is a picture of our "big yellow", with a 2.6 meters wing span.

http://image.rcuniverse.com/forum/upfiles/244552/Ek15393.jpg


We are also looking for twin boom pusher. And though China is making 70% model planes in the world, those planes for UAV is rare. We also have friends in model factories, but they don't want to spend too much time/money on 1 or 2 UAV planes. They work only for wholesales.

However, when I'm reading this thread today, I feel the market is ok for UAV planes. If any one in US can contact me and we can discuss how many planes you need, maybe a batch of UAV planes can be made soon.

And, anybody has a free plan?

[Connexxion]

Hi Red Gol!

Nice plane you've got there.
What engine do you use and what size are those wheels mounted on your bird?
You mentioned you had a autopilot on the plane,what make?

I'm glad I mentioned china and attracted your attention,because we really,really need twin boom pushers and can't find any one who is willing to built them.

The demand for a twin boom pusher doesn't only excist in the USA.
There are also a lot of uav-ers in europe,africa and asia.
So the demand is worldwide.

Keep us up-to-date and thanks in advance.

[Crash Pilot]

Don't forget the demand in Australia.

Bring on the Chinese.

Crash Pilot

[Crash Pilot]

Guys

Maybe we should put together a list of people that want one.
There may be people lurking in the shadows watching this thread that havn't commented yet.

Maybe we can get the numbers for someone to put together a ARF or kit.

If we can get the Chinese interested then they will have it designed,build,tested and delivered to our doors by the end of the week.

Crash Pilot

[kostixx007]

Actually we are working on this problem for few months. My team is developing a modular design twin boom pusher that is capable of adopting a wide range of camera gimbals and equipment. Now we are working on 3-axis video gimbals that is <20 cm in diameter. Gimbals is in prototype stage now, and the price should be very, very attractive. Twin boom pusher is in design stage and price is intended to be very attractive as well; will be available approximately in August- September.
Some of the details :
Molded 3 piece wing (3m), molded inverted V-tail
detachable tail and tail booms
total weight 8-11 kg

Unfortunately I can't post drawings, 3d models or pictures at this moment . Team consists of experienced world class modelers, robotics guys and programming guys.
More details coming soon.

[Connexxion]

Ok guys,let's talk business.

What do we want actually?A TBP with what specs?How much wingspan,how much internal room and what kind of undercarriage?

I suppose we should know what we want so a possible manufacturer knows what he/she has to build.

They need to know what we want,before they can start builiding one.

[fritzdecat]

At the start of this thread RaptorAp showed a picture of a grey plane. I am thinking of a plane about the same size with a 40 sized engine and a wing approx the size of the one on a a tower 40 trainer.

I am not going to hold my breath for some co to make one I'm going to get some balsa and get busy. will of course post the results here :cool:



theres also this..hmm

http://www.reactionresearch.com/aircraft/aircraftindex.htm

[skymind]

Red Gol, we have talked about your yellow airplane before. The wing looks like it is on upside-down.

[kd7ost]

I saw that picture but attributed it to angle and lighting. I don't think it was flat on top. It looked fully or semi symmetrical. But with the light color and sun from above it obscured the real shape from the underneath angle.

Dan

[Crash Pilot]

Connexxion

My Requests

Modular Design for easy transport.

70 inch plus wingspan

1 pound plus pay load

Plenty of room up front for gear and maybe a parachute compartment.

Steerable undercarrage.

Crash Pilot

[Connexxion]

Got that Crash Pilot.

Wondering what the others want the TBP will be.

[red_gol]

Red Gol, we have talked about your yellow airplane before. The wing looks like it is on upside-down.

Hehe, I don't think we are so stupid that made such mistake. I think it's a sort of distortion on that photo. Believe me. The attached photo may help?

[red_gol]

Hi Red Gol!

Nice plane you've got there.
What engine do you use and what size are those wheels mounted on your bird?
You mentioned you had a autopilot on the plane,what make?

I'm glad I mentioned china and attracted your attention,because we really,really need twin boom pushers and can't find any one who is willing to built them.

The demand for a twin boom pusher doesn't only excist in the USA.
There are also a lot of uav-ers in europe,africa and asia.
So the demand is worldwide.

Keep us up-to-date and thanks in advance.

You are welcome. We have a Zenoah 26cc installed but it seems not powerful enough for this heavy gear. With all the servos and receiver, batteries and the auto pilot, gps and a Canon 400D, and also 1 liter gas, the engine has to run 9000rpm to climb.

I think the wheels diameter is about 10". I don't know where my crazy friend got it.

The autopilot is a local made device. It's originally developed by someone from the Beijing University of Aviation and Aerospace. It has the 3 axis gyro and navigated by GPS and barometer.

Attached is a photo taken by this UAV from 400m high. Take it easy - It's not a military base - Just the Aviation Museum of Beijing.

[red_gol]

Ok guys,let's talk business.

What do we want actually?A TBP with what specs?How much wingspan,how much internal room and what kind of undercarriage?

I suppose we should know what we want so a possible manufacturer knows what he/she has to build.

They need to know what we want,before they can start builiding one.


My contribution:

A six kilogram lift (13pd?) - It might be a video camera, high quality video signal transmittion, parachute for emergency landing, batteries, and gas for up to 3 hours flight.

What size it could be?

[Crash Pilot]

A six kilogram lift

cool

Bigger the better I say.

A parachute hatch at the top that hinges back and covers the prop to allow the chut to deploy without getting snagged would be cool.

Just remember this thing will need to be shipped to internationally.


Crash Pilot

[Connexxion]

A six kilogram lift

cool

Bigger the better I say.

A parachute hatch at the top that hinges back and covers the prop to allow the chut to deploy without getting snagged would be cool.

Just remember this thing will need to be shipped to internationally.


Crash Pilot

What do you expect?They will deliver the planes by dropping them internationally out of B-52?LOL!!!

[Crash Pilot]

Connexxion


Why drop them from a B-52.

Just build them the same size as a B-52 and they can fly them over here. LOL :-)

Crash Pilot

[Connexxion]

I've been thinking about the material the TBP has to be built of.
All wood,fiberglass fuselage with wooden wings or complete fiberglass?
I saw an awesome plane called "Flamingo" from Australia.Built by Bob Young.
That one was sleek and I believe of all fiberglass.

So this are our suggestions so far:
-modular design
-capable of at least 6 kg lift
-at least 70 inch wingspan,but (much) more is better.
-a hinged hatch for parachute recovering
-steerable nosewheel/detachable undercarriage?
-plenty of room for electronics and a 1.5liter fueltank

If you find any plans/pictures,please show them so it will be easier to imagine what we're looking for.

[Crash Pilot]

Connexxion


All fibre glass would be great but I think it would add too much weight reducing the payload weight.

70 inch is a bit small I was mainly concerned about shipping. Bigger the better

Have you had any more correspondence from China.

Crash Pilot

[Connexxion]

I spoke to a member of a chinese manufacturer,Maggie Han.

She will talk about the TBP with her boss and let me know whether they're interested or not.

The american guy who lives in china didn't response yet.

[Airboatflyingshp]

Peter It lets you put a singe and possibly messy ICE motor on the centre line with the fuse/wing but out of the way of the optics in the nose ..allowing also for forward and down looking views. It keeps the prop out of the field of view.

With a single boom fuse the motor and prop have to be off the thrust line or the fuse has clear the prop like on a Don Quixote Easystar or Seebee if its a pusher.
If you go for a twin ...multies are OK with electrics...........you can go for a layout like the Piaggio166 or Royal/trekker gull ...........twin pushers keeps the props out of your field of view and the oil slick that comes from oilers.

A twin boom twin has great forward - rearward fields of view as well as up and down for recon craft eg FW UHU recon plane or the P61 Black Widow night fighter burt booms and props can still block some key angles.

UAVs tend to be shaped by function rather than aesthetics.... a box is easy to pack but a tube is more rigid and a bit more stream lined if you want to rotate the nose/camera in at least the one plane perhapse a bit easier to work from.
Aderson greenwood made quite an attractive twin boom light pusher for which plans are available at 51" span but Ben sheershaw did a 120 " very simillar vintage design called XP3.

The other ones to look at is the full size observer plane the Edgely optica :eek: a plexiglass bubble on wings and my favourite jet observation platform the Russian M55 M17 Mystic or Geophysica :cool:

[skymind]

I saw that picture but attributed it to angle and lighting. I don't think it was flat on top. It looked fully or semi symmetrical. But with the light color and sun from above it obscured the real shape from the underneath angle.

DanI was judging by the light colored end-rib. But I'll have to take Red Gol's word for it. He got it up to 400M in any case.

Ok, RedGol. The wing in the next shot is too small for me to tell but I'll take your word. Nice looking bird.

[red_gol]

I've been thinking about the material the TBP has to be built of.
All wood,fiberglass fuselage with wooden wings or complete fiberglass?
I saw an awesome plane called "Flamingo" from Australia.Built by Bob Young.
That one was sleek and I believe of all fiberglass.

So this are our suggestions so far:
-modular design
-capable of at least 6 kg lift
-at least 70 inch wingspan,but (much) more is better.
-a hinged hatch for parachute recovering
-steerable nosewheel/detachable undercarriage?
-plenty of room for electronics and a 1.5liter fueltank

If you find any plans/pictures,please show them so it will be easier to imagine what we're looking for.

70inch for 6kg? Isn't it too small?

[Airboatflyingshp]

If I'm wide of the mark here apologies but

6kg at 70" is a very high load on a conventional wing monoplane even with flaps and slots your going to have to maintain a high airspeed to keep it flying, that limits endurance and flexibility, landings on less than perfect runways could be alarming given the value of the contents. A Light sport - sport, square wing area loadings might be more advisable..think about a dead stick......besides if its naturally more stable and steady in the air you are going to be able to trust it to follow the course you set rather than constantly have to get it to correct its flight just to stay in the air.

Just an Idea -based on the modular concept muted elsewhere - Why not pick a standard span at the mid to lower end of your target range but have a plug in system for the outer wing panel's........... depending on payload , altitude and flying conditions you could alter the performance of whole set up...it would also be easier to transport............. even my old Royal Cessna Skymaster plan also has plug in screw fixed booms.

[Connexxion]

Actually we are working on this problem for few months. My team is developing a modular design twin boom pusher that is capable of adopting a wide range of camera gimbals and equipment. Now we are working on 3-axis video gimbals that is <20 cm in diameter. Gimbals is in prototype stage now, and the price should be very, very attractive. Twin boom pusher is in design stage and price is intended to be very attractive as well; will be available approximately in August- September.
Some of the details :
Molded 3 piece wing (3m), molded inverted V-tail
detachable tail and tail booms
total weight 8-11 kg

Unfortunately I can't post drawings, 3d models or pictures at this moment . Team consists of experienced world class modelers, robotics guys and programming guys.
More details coming soon.

You said it will be very attractive priced.
How much do you have in mind?

[kd7ost]

If I'm wide of the mark here apologies but

6kg at 70" is a very high load on a conventional wing monoplane even with flaps and slots your going to have to maintain a high airspeed to keep it flying, that limits endurance and flexibility, landings on less than perfect runways could be alarming given the value of the contents. A Light sport - sport, square wing area loadings might be more advisable..think about a dead stick......besides if its naturally more stable and steady in the air you are going to be able to trust it to follow the course you set rather than constantly have to get it to correct its flight just to stay in the air.

Just an Idea -based on the modular concept muted elsewhere - Why not pick a standard span at the mid to lower end of your target range but have a plug in system for the outer wing panel's........... depending on payload , altitude and flying conditions you could alter the performance of whole set up...it would also be easier to transport............. even my old Royal Cessna Skymaster plan also has plug in screw fixed booms.


The span alone isn't fully helpful. We need the chord in order to determine the square footage of wing area and calculate weight to square foot of wing.

Larger planes can have higher wing loadings than smaller planes. You can fly a 10 foot span 16 inch chord plane at 50 ounces per square foot quite easily. You wouldn't get a standard speed 400 plane off the ground with those numbers.

Dan

[Mark Harris]

I have this prototype i built today (attached). Its a 1/3rd scale or so of what i want to build (1.8m wingspan).

I test threw it today, it flew 28m on just a really light throw.

On the full size version i plan to have a motor in a protruded in the centre of the wing, and the tail booms mounted a little lower. This will allow me to put upto around a 12" prop on it. Was thinking of powering it with a Eflight Power10 or Power15. From here it could be scaled up further i guess.

I plan on putting a few hours work in on the wing tomorrow.

[kd7ost]

I have this prototype i built today (attached). Its a 1/3rd scale or so of what i want to build (1.8m wingspan).

I test threw it today, it flew 28m on just a really light throw.

On the full size version i plan to have a motor in a protruded in the centre of the wing, and the tail booms mounted a little lower. This will allow me to put upto around a 12" prop on it. Was thinking of powering it with a Eflight Power10 or Power15. From here it could be scaled up further i guess.

I plan on putting a few hours work in on the wing tomorrow.

Nice,

A builder in the fray. :D

Dan

[Mark Harris]

I'm a friend of Crash Pilots, i've been meaning to do this for about 7 months now. This thread + the UAV electronics and such i've been doing pushed me into action hehe.

Guess we'll see how well my plane comes out haha.

[Connexxion]

Nice,

where did you get the plans from?And how much time did you need to build this bird?

Finally someone who puts the action to the words!

[kostixx007]

2 connexxion :
Price we are aiming for is around 900-1200$ quality is compareable to high end- F3J sailplanes

[Airboatflyingshp]

KD lost....I had automatically been thinking about variable chords and span, it just needs an adequate wing panel/root and attachment.

If your center section between the booms has a wide chord, a max chord size - it will provide you with a stronger attachment for your fuselage power /payload pod and the more rigid attachment of the booms.......... at the extreme this takes you towards a pusher version of the Burnelli idea http://www.airbornegrafix.com/HistoricAircraft/Burnelli/OtherBurnelli.htm
but with plug in outer panels and a fuse/payload pod underneath.

Jumping back to Peter -the other aicraft that fits the layout is the Airspeed Argosy.

[Mark Harris]

Nice,

where did you get the plans from?And how much time did you need to build this bird?

Finally someone who puts the action to the words!

I did reply to this, but it didnt seem to post. the plane took around 3 hours to build, and then that again to cover it (first time i've worked with tissue paper/dope). That 3 hours is design and cutting and building.

I made a launcher for it today, it passed its flight test so i thought i'd rocket power it a little *evil grin*.

Only just got started on the wings for the UAV today. cut out the templates, but still need to sand the down to the correct size then i can make all the spars.

[Mark Harris]

Well, i've started to build the wing. Only had about an hour and a half to spend on it so far. Had to build to ramp of death for my little prototype. 2x A10-PT rocket motors should make it go pretty fast ;)

Wing spar construction photos attached and a rough layout of the wing so far. Also attached is the ramp of death :D

[Connexxion]

Thanks Mark,

the prototype already looks neat,but do you have enough space between the booms?

I'll be following your progeress every day,so keep us up to date(please).

[kd7ost]

KD lost....I had automatically been thinking about variable chords and span, it just needs an adequate wing panel/root and attachment.

If your center section between the booms has a wide chord, a max chord size - it will provide you with a stronger attachment for your fuselage power /payload pod and the more rigid attachment of the booms.......... at the extreme this takes you towards a pusher version of the Burnelli idea http://www.airbornegrafix.com/HistoricAircraft/Burnelli/OtherBurnelli.htm
but with plug in outer panels and a fuse/payload pod underneath.

Jumping back to Peter -the other aicraft that fits the layout is the Airspeed Argosy.


Not sure if "KD lost" was a figurative punch at the back of my head or not. :rolleyes:

I've got a handle on my projects. ;) I'll be happy to stay out of your build thread. Sounds like you guys have a handle on it.

Dan

[Brandon Crash]

wow, this thread has moved on some.....

I was looking at a set of wings from nasty toes, 2 parrallel mid sections, and then a pair of swept tips, giving in the region of 8' span. Alas he doesn't ship outside the US (not even to canada). :( So I've got to either nail the foam cutting thing, or clear some bench space, and bash the balsa.

Mark, The concept looks great, I want video of the prototype under rocket power!! :D

Hmmmmmmm just spotted a pair of 100" wings in the corner, need a bit of tlc.... and recovering, but they are ready built. Carl goldberg if I remember.

Can't figure the picture thing out... Do I need to post them on-line first?

[d_wheel]

I hope you don't mind me jumping in here with my latest project. It's not a twin boom pusher, but instead has a single boom. Having taken the week off and planning to do quite a bit of flying, I found myself grounded because of weather. Only got in 3 flights Wednesday morning before the wind once again came up to gale force. This left me pacing the floor so I decided to do something constructive with the time.

I have been kicking this idea around for some time now, and finally got around to "building" a prototype. One of my favorite all time fun-to-fly airplanes is the Ugly Stik. I was learning to fly back when Phil Kraft designed the Stik and have had at least one in my hangar ever since. Its stability and very forgiving flight characteristics seemed to make it a natural as a photographic vehicle except for 1 thing. The darn propeller up front was in the way. Some time back I thought of cutting the fuselage off just behind the wing, adding a boom on the bottom to attach the tail feathers, and installing the motor on top with the propeller just far enough aft to clear the wing. I have been flying a 40 size Big Stik for over 5 years, with various engine, radio, electirc motor configurations, and felt like it was a good candidate.

It only took a little over 2 days to get the first part of the job done (cutting off the fuselage and bolting on the boom and tail), and it certainly looks it! Not a pretty thing to look at but should prove whether or not the concept will work. Before moving the motor to the rear, I test flew this arrangement with it in the original position up front. That was the 3 flights I got in Wednesday morning. It flew perfectly! No problems at all.

The boom is from a Raptor 50. It is mounted to the bottom of the fuselage with 2 Raptor 50 horizontal fin mounts, screwed into hard wood rails which were glued into place. The tail feathers are bolted to a Raptor 50 horizontal fin which was cut off leaving about 1 inch on each side. This is in turn mounted to the boom with it's original mounting hardware. The servos are held in place by double sided tape. Servo wires run through the boom.

After the first flights, I fabricated the motor mounts from hard wood. The vertical pieces are glued to the plywood on the inside of the fuselage just behind the wing with Gorilla glue. The motor mounts themselves are screwed in place so that I can experiment with thrust angles more easily. It looks like the wind will be down to less than 15 mph tomorrow, so I should be able to give it a test flight in this configuration!

The motor is a Mega 22-20-2, connected to a Monster Gear Box - 6.3/1 gear ratio, and 15x10 APC electric prop. Battery is a 5s2p A123, speed control 45 amp CC. With the motor up front it flew very well at 1/2 throttle and gives me about 12 minutes in the air with good throttle management.

If it works well enough, I plan to do the same to a Great Planes Giant Stik. Haven't decided what motor yet, but I have flown this monster with an AXI 5330-18 and 10S LiPo and it is a GREAT performer.

Here's a picture of my hack job (I hope).

PusherStikProfile.jpg

Later;

D.W.

[Mark Harris]

Attached are pictures of it under power. Gotta get a new firewire cable, current one isnt working, so no video until then.

kd7ost, Your plane is incredibly impressive. What motor and prop do you have?

Connexxion, The booms will be mounted lower and slightly further out on the one i am building now.

More wing progress attached. Need 1 more spar glued into place on the end (the board i'm using isnt long enough hehe). Taking a lunch break now but then back to the other wing.

[Mark Harris]

Started my own thread: http://www.rcgroups.com/forums/showthread.php?t=672003#post7277072

[Airboatflyingshp]

Not sure if "KD lost" was a figurative punch at the back of my head or not. :rolleyes:

I've got a handle on my projects. ;) I'll be happy to stay out of your build thread. Sounds like you guys have a handle on it.

Dan

Sorry Dan I hadn't spotted it, my Dyslexic error....................apologies it definitely was not intended.. I'm Mildly dyslexic, dysphasic and I occasionally miss read or type up something odd but this time dohh ..........:o :o I read what my brain was expecting in a name ie a letter not a number :o

I once miss read a 3 as a 5 in a exam and spent ages wandering why I couldn't balance the equation......... my maths tutor new I new how to work out that type of equation...he quickly spotted my Faux pa being himself a dyslexic............... and just started chuckling he got me to re read it several times then do the same with my version :rolleyes: .

Its definitely not in my nature to side swipe anyone like that .I'm here to learn and share ideas not score points against strangers............ Sorry OK?

[Airboatflyingshp]

Mark I like the JATO experiment have you seen the old Opel rocket gliders I think jetex did a version I have a 3 view somewhere?

[Mark Harris]

Hmm havent seen them. Rocket products are few and far between here sadly, rocket motors are around 7 times what they sell for in the USA.

[kd7ost]

kd7ost, Your plane is incredibly impressive. What motor and prop do you have?



Thanks Mark,

It's getting almost three years old now. I designed it for the express purpose of taking vertical agricultural photography.

It has a 102 inch span and is 87 inches long. It weighs 20 pounds. Power is from a Fuji BT32A. I've used 18x8 wooden zinger pushers but have out swapped to a Master Airscrew 16x10 glass filled nylon three bladed prop.

The plane features a small board camera in a nose turret that I can move in pitch from 0 degrees to down beyond 90 degrees. I built a video switch that operates from that same pulse I use to move that camera. It works fine but doesn't have great Hysteresis for switching. I can work with it though in my application.

The idea is I take off and get to altitude. Using the nose camera I work with the crop manager, land owner what have you to view the downlink to ensure I'm heading to the right field. As I move over the field, I rotate the nose camera down and steer with rudder to stay centered on the field. The FOV of the small camera closely replicates my Fuji finepix E510 in the fixed, vibration isolated vertical mount mid fuselage.

I have the nose camera and video switch set up so that as I'm nearing the edge of the field, the pulse I'm using to tilt the nose camera activates the video switch and puts the Fuji camera AV output on line. Now I can see whet the still camera sees and can make any final little flight tweaks to frame up the field. Once centered, I simply activate the shutter and take the picture.

The plane uses a co-pilot set on roll so when I'm flying with the downlink I simply steer around with rudders. The engine is slightly pitched up so that under full throttle the plane slightly climbs. In this way I don't have to pitch and roll from the AV downlink view. That's a little risky and the pilot might stall. I found early on that when I'm looking vertical from the plane the illusion is that you're descending. Your brain tells you to pull up elevator and if overdone a stall will ensue. I use a GPS overlay with altitude readouts. The altitude is in meters but its still instrumentation. I can glance at the numbers and tell I'm not gaining or losing altitude. I finally got used to the down view and trust my system to work like designed and set up.

There is a PDC-10 from UNAV onboard with a GPS that I can activate from a spare channel or, PCM failsafe will activate it and cause the plane to loiter over my position. This is in case of interference, transmitter to receiver link loss or if I just get turned around and want to get back overhead in the most expeditious manner. I use a spotter and operate from remote agriculture areas.

As of today, I haven’t reset the trip information on the GPS and it has logged a little in excess of 2,200 miles.

Here’s a link to a video showing how it looks from the downlink.
One problem that is causing me to redesign to a single tail boom is that everything on this plane is pretty much on line. The engine has plenty of ground clearance but on a take off run on gravel it has a habit of vacuuming rocks. The wooden ones have shattered pretty bad and at 25.00 a pop I couldn’t keep replacing props. The three bladed prop helped out but it still pulls up rocks. I’ve thrown a few blades on a gravel takeoff run and you can tell when that happens. It sets up quite a buzz and you lose power fast. I’ve reverted to taking off on dirt, grass or pavement as a result. The next gasser will have a few design features changed to simplify operations internally and raise the engine higher to keep it clear of FOD.

Short Ag thread with link to video.

http://www.rcgroups.com/forums/showthread.php?t=571185

I built an electric single tail boom that incorporates some of those changes. It’s only 6.5 pounds so I just hand launch it anyway but the prop has a lot more clearance. I call that one the Dragonfly and did a rather extensive build thread on it here.

http://www.rcgroups.com/forums/showthread.php?t=573747

Dan

[kd7ost]

Sorry Dan I hadn't spotted it, my Dyslexic error....................apologies it definitely was not intended.. I'm Mildly dyslexic, dysphasic and I occasionally miss read or type up something odd but this time dohh ..........:o :o I read what my brain was expecting in a name ie a letter not a number :o

I once miss read a 3 as a 5 in a exam and spent ages wandering why I couldn't balance the equation......... my maths tutor new I new how to work out that type of equation...he quickly spotted my Faux pa being himself a dyslexic............... and just started chuckling he got me to re read it several times then do the same with my version :rolleyes: .

Its definitely not in my nature to side swipe anyone like that .I'm here to learn and share ideas not score points against strangers............ Sorry OK?

No problems then Airboat. kd7ost is my Technician class Ham radio call sign so you're accidental letter swap looked pretty good. :D

I've accomplished quite a bit but I try not to come across like a know it all. It puts people off, and of course I certainly don't know it all. I do realize though, sometimes if I know a topic and jump in with answers or questions I can give the impression of being a know it all and I thought maybe I had ticked you off by my question. Threads are a slow way to get to know people.

It's all fixed now and thanks for the explanation. We're good. ;)

Dan

[workshop]

KD7OST,

You may not know it all but you come closer than anyone I know! :D

Thanks for the Pegasus write up. That vehicle is LEGANDARY on this forum and it is great to see those close up photos.

Airboatship (Clive) is a super guy and one hell of a researcher! I'm glad you guys worked it out but I'm afraid the new mnemonic for your callsign is sticking in my head... :rolleyes:

Jeff

[d_wheel]

I flew the PusherStik this morning and am pleased. It needs a bit of tweaking to get things just right (motor thrust angle) but that was not totally unexpected and shouldn't be a problem.

KD7OST, have you given any thought to the design of your single boom UAV? Please keep us informed if you come up with something.

Later;

D.W.

[kd7ost]

Thanks all,

I did start a build thread on the new "Pegasus2" here but it's grown quiet. I've been swamped at work and have had to shift other builds to the front. These are pretty big undertakings unless you get to just build full time. :(

Dan

http://www.rcgroups.com/forums/showthread.php?t=608052

[fly_asmara]

Hi All,

Interesting discussion. Thought I contribute some of my experience building tail boom pushers. I have a tail boom airframe here with me that I designed and built for various purposes related to UAV operations. From my experience building RC planes, this was the most challenging! Yeap, no plan to follow, no blue print - start from ground zero. But it was exciting because you can decide from the beginning what you want to carry onboard the aircraft i.e cameras, transmitters, magnetometers etc etc, work out their weights, place the CG and work through the design process. There was an element of 'unknown' as to whether the prototype will fly or not eventually, and if it does, good enough to be a UAV? 'Can the equations be trusted? Are these numbers for real?'. Out comes all the fundamental of flight books from the cabinet. The first few flight tests of the prototype were hair raising. CG is a big issue for tailboomers. All aircraft components built and assembled, I found that tail boom aircraft are very sensative to CG change than any other. Also make sure that the wings are designed with high aspect ratio. The extra directional stability will greatly help due to lack of fuselage-body-self-correcting factor.

Here are some photos of my plane.

It's inverted V-tail design. In terms of handling really the bird flew no different than any other conventional design, took less than 5mins to assmeble but to my eyes the airframe looks 'sweeter' and gives it a character with the inverted V-tail. Its made from composite material, mostly fiberglass and lightweight material. The airframe weighs approximately 8kg minus the engine. To date I have tested the airframe with UAV autopilot systems (200 flying hours with Micropilot MP2028g (hold on to your seats with this one) - and survived ;)), complete with camera pod installed with video cameras for live image transmission. At the moment I'm using a Zenoah 80cc engine to give it that extra push, but have also tested it with the 62 and works as well. Wing span is slightly more than 3m long tip to tip, and length is 2.5m. She has carried 15kg on 120m runway but given a longer runway the aircraft can take in a lot more.

I have a couple of theories why there aren't that many tail boom airframe out there in the market but feel free to kill them. It took me ages to design, test, and fabricate a tail boom airframe! Fine tuning the design alone is the most challenging part (and $$$$) to get the right stability and CG balanced. But perhaps the biggest stumbling block is the choice of engine. You need a pusher. Not many out there make pushers. If you are thinking of using of the shelves engine, try to guess why conventional propellars don't work as pushers :). I haven't read all the messages in the forum so if someone else have mentioned these 'theories' before, then I'm just a broken record :). Sorry ya.

Its great airframe to use to conduct aerial based projects because of the space available for you to put your stuffs in the fuselage. Most of my clients are companies. But I have to confess that the cost of making is not cheap. 4 persons job took between 3-5 months. Its hand made. I would love to hear from anyone who has any idea on ways to automate the production of complete composite structures such as wings (with spars and ribs etc).

I am also making the smaller scale tail boom version made from fiberglass perhaps for those who like to fly for fun. Its going to be made affordable so will be happy to come back into the forum and let everyone know when its ready :).

For your information, I am not from China :) but close, Malaysia.

Thanks for the chance to share:).

[Mark Harris]

Very sexy plane fly_asmara! Pitty about the inverted vtail though.. oh how i hate vtails haha.

Happen to have plans for this lovely plane?

[Airboatflyingshp]

Fine tuning the design alone is the most challenging part (and $$$$) to get the right stability and CG balanced.......................................... ..........

What effect would adding canards even fixed ones have............. this is an applied question in this context Im wandering if it might ease the problem as well as bring the Canards anti stall characteristics to the UAV.

There is a huge general thread on Canards here http://www.rcgroups.com/forums/showthread.php?t=613556

Next bit you guys are hauling substantial and expensive payloads around, wing performance is important yet I dont often see wing fences and or tip plates/fins being used...........I'm thinking Canadair water bomber style.

[Myron]

Hey guys,

This is turning out to be a great thread.. Although we dont do alot with our twin boom designs any longer(the wing is the thing) but I thought I would throw in a few pics of our "test bed".. Gene is in Cali this week tweeking on the autopilot with the mfg and hopefully he will be bringing back some extra units for this bird and a a couple of our wings.. Anyway, here it is

87" wing
35" vacu formed ABS fuse.. Its solid as a rock and doesnt need formers and its basically completely hollow other than a 24oz tank.
G-26 with an 18x6 The motor is new and we ran it a little rich and the top speed was 67.9MPH.
Fly weight with just enough ballast in the nose was 17 lbs with 24oz of fuel. We expect to carry a total of 7lbs payload once we distribute the weight a bit more...

Myron

[Airboatflyingshp]

And there we were thinking we had our first LPG powered UAV........................... :rolleyes: ;) :D

[fly_asmara]

Hi guys,

Nice looking bird there Myron. When I saw the tanks in the fuselage I thought whooaa... something I saw once in the Fast and Furious:)). Canards and tip plates? Yeah it helps but perhaps really without them the aircraft flew really well already. When I was designing, I was forcing myself to minimise weight and drag on the bird. Hence, chuck away stuff I don't really need. After working out the pieces from 'educational flight testings' the real issue I had to iron out is not the airflow across the lifting surfaces but balancing the CG with all equipment onboard. And making sure the engine is strong and reliable too :). Hey Mark, heh heh.. inverted V-tails are the way to go. The plan is all over the place so afraid can't put anything up yet for now. All the best!

--
fly_asmara

[HELModels]

CG is a big issue for tailboomers. All aircraft components built and assembled, I found that tail boom aircraft are very sensative to CG change than any other. Also make sure that the wings are designed with high aspect ratio. The extra directional stability will greatly help due to lack of fuselage-body-self-correcting factor.

:).

Absolutely, fuselages do nothing for stability, they are always a destabilizing factor. The CG on a pod and boom pusher actually gives you more options. If the the CG needs to go way back, add a bigger motor. If the CG is too far back, add more equipment, like a bigger battery. You cant do that as easily with a conventional design. Pushers are arranged "around" the CG. BTW, that is a nice looking plane.

[Myron]

Hey Guys,

Someone out there is probabaly doing just that, powering a system with LP that is.. I dont think that is in the plans for us though! One thing I have discovered with this config with the tail sitting way up high is the ability to come in with the nose at a very high angle of attack which really slows the bird down fast for greaser landings. Also manipulating the payload for proper CG is easy.. Right now it has 2lbs of lead in the nose in front of the nose gear to get it to balance.. It has enough room in there to put almost anything in the 5-7 lb range evenly spaced. The 24oz tank is right under the center of the wing and we have room with a "bladder type" tank to get upwards of 48oz of fuel in it if we needed to.. We can also balast up the tail if we need to carry more weight in the nose...

Myron

[MX]

To keep this thread going:

I've got a set of ARF wings from a GreatPlanes Spirit Elite. It's 78.5" span with flaps and ailerons. 645 sq. in. area. I'm wondering how well that might work in an electric twin-boom design. I'm thinking I'll build a simple boxy pod for a fuselage. Figure around 3 - 4 pounds, AUW. Designing the electronics to go into the plane keeps me busy, so I don't have a lot of aircraft building time. I'm trying to pull together various ARF components into a useable platform for testing my electronics.

Opinions?

MX

[kd7ost]

It looks like a great wing. Flaps as well as ailerons look great. It might be hard to go in and "add structure" to the wings for booms. And the wings were probably not designed to handle that kind of weight putting torque up and down on the trailing edge.

It might be easier to build it up with a single tail boom like I did on my Dragonfly. I used a glider wing for that design but no flaps. It was a pretty simple box design as well. It would make your project go faster as you won't have to mess with the wings to attach booms.

Dan

[MX]

Yes, the torque on the wing was one of my concerns. I am also considering the single boom, but that requires the motor be up on a pylon for clearance. How do you compensate for the pitching effect of the motor? Just with some up elevator? Or is it insignificant?

MX