what's this then?

[bugdevheli]

:D :D

http://img.photobucket.com/albums/v28/eboki/not%20sophs%20stuff/heli002.jpg

[kissmysquirrel]

Something Father Christmas might shove in his 'sack'?:E

Looks like a widowmaker to me.

[Sudden Stop]

Looks like a close up of something your nephew would demand you glue together straight after unwrapping on the living room floor on christmas morning :ok:

[rotorcraig]

Looks like a widowmaker to meCome on, it could be worse! (http://www.math.byu.edu/~stafford/plummerfamily/jon/acecraft/photos/Learn/LearnToFly.html)

http://www.math.byu.edu/~stafford/plummerfamily/jon/acecraft/news/KitPlanes/GENH-4OshkoshDemo.jpg

RC

[UwantME2landWHERE!]

Maybe no help, but another pic.

http://www.deltaweb.co.uk/eagles/weston06.htm

[wg13_dummy]

The big thick centre post would be a tad obstrusive for forward look out.

WTF is that on the head on the first picture??

[g-mady]

Just seen that second pic in Heli Life this month - says they have 4, 2stroke engines, and if one fails the others allow you to fly (I imagine it means land safely!)

I havn't been able to work out how Yaw is achieved on it though???

MADY

[Overt Auk]

wg13

That is the rotary clothes dryer. It's on the Aussie mods list.

OA

[kissmysquirrel]

So technically then its a multi engine for the purposes of certification?:hmm:

Wnder if you'd actually survive 8 hours for the initial conversion. maybe you get a medal as well as a type rating on it?:E :E

[rotorcraig]

Another photo, and a bit of an explanation this time...

http://www.hmfriends.org.uk/images/hd06copebug3_73.jpg
Ben Cope's Bug Mk.3, G-BXTV, evolved from his Mk.1 simulator displayed at Helidays in 2002.

Credit: Friends of the [Weston-super-Mare] Helicopter Museum (http://www.hmfriends.org.uk/hd06subgal.htm)

RC

[rotorcraig]

Bugdevheli, looks like Santa came early this year (http://www.pprune.org/forums/showthread.php?t=113241)?

RC

[on21]

I was just wondering what this machine is like for a jolly, compared to say an R22 as a personal helicopter? Does it have any terrible traits (other than the ones every other helicopter suffers from)?

http://www1.airliners.net/open.file?id=1094204&WxsIERv=PU-7%20Uryv-Fcbeg%20Xbzcerff%20Puneyvr&Wm=0&WdsYXMg=Hagvgyrq%20%28PU7-Uryv-Fcbeg%29&QtODMg=Ylbaf%20-%20Oeba%20%28YLA%20%2F%20YSYL%29&ERDLTkt=Senapr&ktODMp=Whar%2016%2C%202006&BP=0&WNEb25u=Wnpdhrf%20Yvraneq&xsIERvdWdsY=V-8300&MgTUQtODMgKE=Ng%20Nivnrkcb%20-%20Punffvrh&YXMgTUQtODMgKERD=1044&NEb25uZWxs=2006-08-13%2001%3A55%3A38&ODJ9dvCE=&O89Dcjdg=&static=yes&width=1100&height=856&sok=JURER%20%20%28ZNGPU%20%28nvepensg%2Cnveyvar%2Ccynpr%2Ccu bgb_qngr%2Cpbhagel%2Cerznex%2Ccubgbtencure%2Crznvy%2Clrne%2C ert%2Cnvepensg_trarevp%2Cpa%2Cpbqr%29%20NTNVAFG%20%28%27%2B% 22PU-7%22%20%2B%22Uryv-Fcbeg%22%27%20VA%20OBBYRNA%20ZBQR%29%29%20%20BEQRE%20OL%20cu bgb_vq%20QRFP&photo_nr=1&prev_id=&next_id=NEXTID

[CRAN]

Bug,

Looks like you have been busy!

Try not to take too much notice of the nay-sayers, why don't you tell us a little about it?

What engine does it use?

What does the feature on top of the hub do?

What performance does it have?

What are you going to do with it next?

Looking forward to your reply!

CRAN
:ok:

[Graviman]

Looks like a lot of dedication has gone into that little machine, BugDevHeli!

What powertrain does it use, or was it all developed for that machine? Looks like R22 MR G/box. Lot of development...

Mart

[slowrotor]

I think it looks very good. Sort of bug-like, I like the cockpit shape.
Lets here more about the design!

[rotorcraig]

I'd like to hear more about it!

Was thinking at work today ... how would one go about type conversion to a single seater???!! What do the CAA say about the logistics of adding one to a PPL(H) licence?

RC

[bugdevheli]

crangravyslorotorcraig. Thanks for the less urine extracting fedback. The machine has a total auw of 500lbs a 20 ft rotor span and is powered by a BMW 750cc watercooled engine. Rotor blades are shortened 22 with a carbon kevlar composite root. Tail rotor, carbon fibre. Tail rotor driven via conventional drive shaft to tail gearbox. cyclic and collective via push pull cables with a device that permits the phase lag to be manually adjusted during testing. Power is transmitted via 5 vee belts, the engine being pivoted at its rear end and is pushed down by a motor and worm gear to tension the belts.. skid gear is a mixture of carbon and alloy. The screens are blown in polycarbonate. The little device propped on top of the rotor is a 5 foot model of my patented ring rotor system. This rotor system provides very high inertia without the necessity for a huge hub whilst at the same time reduces tip losses to a minimum due to its blade ring tiplets. Bug 3 is currently being tested ground tethered to prove as far as is possible any weaknesses in any critical components. Once this testing programme is completed a full sized ring rotor, which is under construction will be fitted ,and the necessary testing to verify that the fluid dynamic analysis that has been carried out on the ring rotor,works as the test results would suggest, I may then be somewhere near the goal of producing a vlh machine that is reasonably safe .

[bugdevheli]

crangravyslorotorcraig. Thanks for the less urine extracting fedback. The machine has a total auw of 500lbs a 20 ft rotor span and is powered by a BMW 750cc watercooled engine. Rotor blades are shortened 22 with a carbon kevlar composite root. Tail rotor, carbon fibre. Tail rotor driven via conventional drive shaft to tail gearbox. cyclic and collective via push pull cables with a device that permits the phase lag to be manually adjusted during testing. Power is transmitted via 5 vee belts, the engine being pivoted at its rear end and is pushed down by a motor and worm gear to tension the belts.. skid gear is a mixture of carbon and alloy. The screens are blown in polycarbonate. The little device propped on top of the rotor is a 5 foot model of my patented ring rotor system. This rotor system provides very high inertia without the necessity for a huge hub whilst at the same time reduces tip losses to a minimum due to its blade ring tiplets. Bug 3 is currently being tested ground tethered to prove as far as is possible any weaknesses in any critical components. Once this testing programme is completed a full sized ring rotor, which is under construction will be fitted ,and the necessary testing to verify that the fluid dynamic analysis that has been carried out on the ring rotor,works as the test results would suggest, I may then be somewhere near the goal of producing a vlh machine that is reasonably safe .

[kissmysquirrel]

I didn't realise it was April 1st.:E It is only a simulator, right? ;)

So why is a part of it for sale on Ebay then?
http://cgi.ebay.co.uk/HELICOPTER-FLIGHT-SIMULATOR_W0QQitemZ190059834029QQihZ009QQcategoryZ2983QQssPa geNameZWDVWQQrdZ1QQcmdZViewItem

[bugdevheli]

In reply to kiss my squirrel. 1. The machine on the pprune post is a complete homebuilt helicopter. the advert on ebay is meant to asses the likely market for a simulator that looks very similar to the one you see on prune. So as not to offend ebay by simply using there service as an advertising means, i have offered for sale (as the advert clearly states) a fibre glass body. 2, As it is approaching the festive season i thought it might raise a few serious queries as to what the object was on top of the rotor shaft. WRONG AGAIN ,oh well, perhaps this explanation clears it all up. or maybe!!!

[slowrotor]

Bug,
Is the 5 foot rotor ring model a test for a full size 20 foot ring?

[bugdevheli]

slowrotor. Yes. I have been researching this system for the last twelve months. The objective was to determine whether it was possible to increase inertia without placing unacceptable loads on the blades, and without the necessity to have a heavy hub to carry the centrifugal forces. I have also during the development managed to reduce the tip loss factor quite dramatically. I am in the process of manufacturing a full size rotor system which i will be testing during next summer. Bug

[UwantME2landWHERE!]

Never mind all the research.....:confused:

Get it certified and start selling them.....I'll put an order in for one of the first 'B' versions.

(never fly the 'A' of anything) ;)

[helimutt]

as long as it comes in at under 10k, i'm sure it will be a hit.
Bugdev, I would like to make a wager with you that it'll never get certificated. Call me cynical but with EASA these days and the rest of the aviation system we have nowadays, a new 'type' isn't going to be easy to certify. :hmm:

[Graviman]

BugDevHeli,

That ring rotor is the business! :ok: I mentioned the possibility on Rotorheads a while back, since Bell apparently tried it in a tail rotor - the response at the time was that the aerodynamicists would fall about laughing. ;)

The way they work is clever. Normally the tip vortex gets washed away with the downwash, but the ring traps the vortex to rotate about it's circumference. The final result is that the airflow looks more like it would in a fenestron (30% effective radius increase), but without the weight penalty. The ring doesn't even need to be that stiff, since centrifugal force (by centripetal acceleration) takes care of shape. The rotor behaves like the theoretically ideal case of an infinite number of slender rotors.

I looked up some figure of Merit stuff in Prouty recently, and have come to some interesting conclusions. The number of blades is (all things being equal) chosen to keep the blade aspect ratio about 20:1 from memory. In fact a high solidity ratio is beneficial for hover figure of merit, and ring rotors will benefit from this. This will be equally true in forward flight, since Nr may be kept relatively slow. However, I would carefully investigate how forward flight affects the ring trapped vortex stability before going too far.

I have some other questions about the "delta3" trimmer, since i imagine you will eventually be aiming the ring rotor at a rigid head. Have you had to chose a specific Nr to get wee-wa d3 and coning d3 the same? I asked this since Comanche had variable "delta3" ( with d3=fn(Nr,Lock No.) ) although the 15% effective hinge offset would suggests ~10 degrees d3 (i use quotes because in both cases the change is affected by control system not head geometry). Since wee-wa is a result of rotor gyroscopic behaviour, increasing Nr will cause increased d3 correction. Since rotor coning is a result of rotor out of plane geometry, increasing Nr will cause reduced d3 correction. Since you are using R22 components i imagine 18 degrees is your starting point, but have you had to play with Nr for it to work?

I imagine you to be very familiar with rotor dynamics, i figured it from reading Frank Robinson's and Nick Lappos' stuff anyhow! :cool:


Mart

[CRAN]

Bug et al,

As you know I am a big fan of anyone attempting to pioneer anything that will improve the performance and safety of helicopters; kit built or otherwise and I thoroughly commend your progress to date. However, there is one glaringly obvious question that must be asked:

Why bother, attempting to pioneer new risky technologies on a machine where the cost (both purchase and operating) is the key market driver. There are few (if any) serious contenders for low-cost lightweight single and twin seat helicopters on the market anywhere. Why not use your engineering know-how to produce a £15K safe single seater and a £30K safe two seat recreational helicopter? Think of the number of people that you could sell to then... With a sufficiently simple machine there might even be a case for a NPPL(H)!

CRAN

[slowrotor]

Bug,
I don't see how a ring would have any less centrifugal loading on the hub than a blade with tip weights would have.

[bugdevheli]

slowrotor. heres a brain teaser for you. centrifugal force wants to pull the blades off. If the blades are retained by a ring are the blades still pulling directly on the hub, or are they now pushing on the ring? if they are pushing on the ring where is the load going then? Now consider that they both pull on the hub and push on the ring? Another little anomoly of course, no lead lag!

[slowrotor]

Bug,
Sure, that makes sense. But the ring is stressed in tension, same as any normal blade, so I am not sure that a ring is any better than direct tension to the hub.
I do think the ring has merit for lead lag as you suggest, and preventing flutter with multiple light blades.
I have a small RC model with a tip ring and very light duty blades, it can hit things without harm.

The ring could be a wire if the load is pure tension.

[bugdevheli]

slowrotor. When you surround the blades with a ring centrifugal force from the end of the blade is contained and redirected around the ring itself, the blades now have a certain ammount of pull on the hub and a certain ammount of push on the ring. Depending on the elasticity of the ring it is possible to put what ammount of centrifugal force you rquire on the hub itself. It is therefore possible to add as much weight to the ring to give the inertia required without loading the hub as is the case if you simply add tip weight to a conventional rotor blade. Regards Bug

[Graviman]

BugDevHeli,

This sounds like the turbine blade/disk vs blisk problem, if you want to do some viability homework. The secret is to minimise the mass in the ring, so that there is enough hoop stress left over to take some blade centrifugal "pressure" distribution. Then load can be shared between hub and ring.

Don't forget that if you are eventually going for the benefits of rigid rotor, only the hub can transfer the bending moments. The stabilising force keeping the blades in plane will also not be generated by the ring.

I remember a conversation with a colleague who had spent some time at Rolls. The ring in a blisk is more for aerodynamic reasons, to stop backflow leakage, and is only really strong enough to take it's own weight.

Don't take my word for this, but at least convince yourself the concept is right. If it is then best of luck keeping the tradition of innovation alive! :ok:

Mart

[slowrotor]

I think the ring would require more material to resist the outward force than a direct to hub tension rod.
Think of a high wire circus act. The force of a 170lb performer on the wire puts several thousand pounds of tension in the wire. On the other hand, a small wire could lift the performer straight up with just 170lb tension.

Sorry, I don't think the ring is better.

[bugdevheli]

Slowrotor,Graviman Thanks for constructive feedback. I dont want to give too many details on prune about the ring construction or tiplets and it has just cost me a small fortune the pay for the fluid dynamic analysis. What i can say is that the ring has a special profile that minimises airflow disruption during foreward flight and if sufficiently rigid in the horizontal axis to remove any blade flutter,or lead lag. The blades on my ring rotor adopt a different shape compared to conventional blades when under coning loads. the blades cone near the hub but go horizontal near the tips. As a side issue the rotor is very quiet more of a hum than a whop whop. Music to the ears! Based on the model it is possible to produce a rotor giving as much lift as a 22 having 5 times the inertia and being a little over half its weight.

[Graviman]

BugDevHeli,

Your post already tells me you are very serious about this concept. I understand what you are saying about the construction required to keep the tips horizontal, but out of respect for your commercial rights will not comment further. Very clever idea.

I imagine the ring aerodynamically performs well with forward flight climb/descent and with gusts?

Based on the model it is possible to produce a rotor giving as much lift as a 22 having 5 times the inertia and being a little over half its weight.

I wish you every success with this concept. I imagine you have a flight test program planned out for either the full size or the scale model. My experience with computer simulation (my specialisation is FEA) is that it is very good for establishing viability or comparing two alternates. The final performance will never be quite what the computer predicts, since the code is based on linear mathematical ideals. Testing is the only way to prove both the aerodynamics and the structure.

You may have hit the timing right on the head. Sikorsky will soon be demonstrating the X2, which is based on rigid rotor technology. Once you have test data to prove out your idea, i would seriously consider approaching them for either a technology development or licensing budget. I really can't comment about other manufacturers, since i gained any heli knowledge from the "local" Sikorsky representative. ;)

Mart

[bugdevheli]

Graviman. Thanks again for the positive observations. As you rightly say, all the prototypes and theoretical modelling only gives a rough idea of wether in the real world it will work. The only way foreward is to make a full size prototype and try it for real. If anyone out there has nice deep pockets then give me a call! The plan is to have a full size version on test, mounted on the homebuilt Bug3 by late summer next year. Thanks Bug.

[Graviman]

The plan is to have a full size version on test, mounted on the homebuilt Bug3 by late summer next year.

Bug, i'm sure you are responsibly going through the cert process but just a bit of advice from a fellow engineer. Since the drawings will have been done for one prototype, i would build two. The second one keep on the ground in a whirl tower, electrically driven so you can run it ~24/7. Continously cycle it through idle/takeoff/hover/climb/flight/extreme_manouvre/descend/auto/land/shutdown, or as much as you can simulate in a whirltower (use a 2nd or 3rd fan if possible for airflow). Keep a computer log if possible about completed cycles, and high speed film of the last 15 mins say (so you can see how any individual fault developed).

Since Bug3 uses proven R22 components, you need to be at least as convinced about reliability of your components as these. Regularly inspect the ground test prototype for cracks, i don't know what techniques exist for composite. I would suggest strain guaging stess hotspots, but don't know if kit exist to get strain data to static receiver. The idea is you can correlate ground accelerated durability test hours to actual flight hours (normally stress PSDF vs freq is compared). If there should be a design defect, you will detect it well before it puts anyone at risk. The flying prototype can then concentrate on performance development to begin with. This will also help the money men gain confidence in your product.

I imagine you have used some FEA code? I use I-deas for my day job, but wouldn't recommend it! :ugh:

Mart