Design and build an 'Ultralight'

[Deskpilot]

Thanks for the offer Harris, I'll get back to you if I need help.

 

Ozzie, great find, and thanks for going to so much trouble. I went to Scotts site but keep getting error 404 ?? Anyway folks, I'm not alone in my endevours. Would be great to be able the follow up on each of those planes. Any ideas as to how?

 

Photo #1 Is that an electric motor haning there? Looks very heavy and complicated whatever it is.

 

Photo #2 Light, simple and easy belt tension.

 

Photo #3 The hidden prop, I like it.

 

Photo #4 Make that into a shoulder/mid wing and a tricycle u/c and it's more what I'm after. I wish there was a photo of the engine/prop installation for this one.

 

 

[Guest ozzie]

Vintage UltraLight Association try this link

[Deskpilot]

Cheers Ozzie, already sent an email to Scott.

 

 

[Guest zutug]

I have a Dragon fly by Bob Bailey.it looks like what yo[ATTACH]7382.vB[/ATTACH] are doing.

 

 

 

[Downunder]

I'm a bit late on the scene but for your prop hub, there are combined bearings with both radial and thrust properties built in. See the SKF web site.

 

SKF Group - Bearings and units Lubrication solutions Mechatronics Seals Services - SKF.com (Rolling Bearings)-Angular contact ball bearings,

 

Combined needle roller bearings,

 

Probably need a shoulder on the mounting sleeve (to push against) or a good way of fixing the inner race.

 

Regards,

 

R J Mitchell

 

 

[Deskpilot]

Hi guys,

 

Zutug, don't want to offend you but your Dragon Fly is nothing like what I'm proposing. Please read my whole thread to see why.

 

RJ, thanks for your input and link. It'll be a while before I need to actually specify my needs re bearings, but it's nice to have the links handy.

 

 

[Deskpilot]

As an aside, have you all seen my post 'The Lightning that never Flew' under the Military heading. No feed back as yet so I don't know how many of you go there.

 

 

[Guest ROM]

A home designed and built fabric and tube ultralight with a gear driven 4 bladed scimitar prop mounted on and rotating around the tail boom is / was located at the private Lethbridge strip in southern Victoria.

 

Overhead wing design.

 

The fuel tank was located behind the pilot with the engine behind the fuel tank and slung beneath the tail boom and driving the prop through an open set of spur gears.

 

The howl from those open spur gears must have been horrendous.

 

The rudder / elevators were a crucifix to keep the prop clear of the ground.

 

It was hangared at Lethbridge some 3 or 4 years ago when I last saw it and may still be there.

 

 

[Deskpilot]

Any one else have knowledge of this plane? Sounds a little like the Russian design I came across recently. Search this site, some interesting stuff there. It's in English.

 

Swift - Soviet Homebuilt Ultralight & Aircraft directory

 

 

[topspeed]

Hello Mr.Manfield,

 

I think this concept or yours is interesting and in several point better than mine at economical fast aeroplane

 

I recall Edson Fessenden Gallaudet of Rhode Island USA had that same concept in the early 1910s.

 

See ya gentlemen and ladies later !

 

rgds,

 

Juke from Up North ( Finland ).

 

 

[Deskpilot]

Hi Topspeed, to our forums. You're already known to a few of our members as we also go onto the Key Publishing Ltd Aviation Forums - Powered by vBulletin site. I took some time out this morning a perused your blog. Wish I could read Finnish. Tell me/us, why were you banned from your home sites? Sure, you have some 'out there' idea's but there's got to be more than that to get banned. I warn you, in a friendly way, we also have a banning system so choose your words carefully.

 

We've both come up with the problem of varying weight pilots. My answer is to design for the heaviest and have a compartment on the nose to add weight for the lighter ones. It should be easy enough to produce a graded scale and affix it to the aircraft for permanent referrence (ie, in case the aircraft is sold).

 

BTW, Mr. Mansfield is rather formal. Call me Deskpilot or Doug.

 

 

[topspeed]

Key Publishing Ltd Aviation Forums - Powered by vBulletin [/url]site. I took some time out this morning a perused your blog. Wish I could read Finnish. Tell me/us, why were you banned from your home sites? Sure, you have some 'out there' idea's but there's got to be more than that to get banned. I warn you, in a friendly way, we also have a banning system so choose your words carefully.We've both come up with the problem of varying weight pilots. My answer is to design for the heaviest and have a compartment on the nose to add weight for the lighter ones. It should be easy enough to produce a graded scale and affix it to the aircraft for permanent referrence (ie, in case the aircraft is sold).

 

BTW, Mr. Mansfield is rather formal. Call me Deskpilot or Doug.

Hello Doug,

 

Since I have nothing to hide and I wanna be straight I did mention in my blog being banned from three finnish aviation forums.

 

I have really no direct answer to why I was banned. It would require a lenghty story, but I think it is because I am too direct bringing my ideas into forums. There is very little toleration if I repeat something too many times. I do have to confess that I claimed that a pusher of mine ( in the specs ) would have a mileage of 300+. I did not have much basis on that except that I calculated the drag and knew the fuel consumption of the APT 11.6 cu in engine at 65% power ( 1.7 liters/hr )..and the drag was .34 sq ft ( about 1/16th of a Cessna 172 ). It all depends how fast the plane could cruise at 65% power..if it is less than 100 mph then the 300 mpg is baloney. We cannot be really sure unless a plane is built and flown.

 

I have a written ( e-mail ) from a finnish EAA certified testpilot that he would fly the plane if built. TKK ( technical university ) educated Air Force test pilot declined after commenting it 5 times..saying he does not like small aeroplanes.

 

The banns started earlier because I also commented on a golf site and on a model aviation site. Some of the model builders were also golfers and for some reason also the stories I told about golfing weren't credible to few engineers of TKK ( see I am from the neck of the woods..from northern Finland ). One of the not credible stories was my 270 yard stroke with a 5 iron ( which went 50 meters past the hole..and took 20 minutes to find the ball and also bent the shaft of the club). My clubs are 1 inch longer than normal. I used to use 2 iron ( stiff shaft + 2 inch longer ) for driving like Tiger Woods in early nineties and regularly teed 235 meters with it. Few years ago I broke my back and used heavy medication ( Tramall...opiats and panacod..it has codein..which Howard Hughes was addicted to ) and spent my time in the web telling tales of my most incredible golf stories as a GF player with par( even ) rounds ( 9 holes max ).I also introduced my Reno Racer TS II in 2003..which became a laughing stock here among educated aero engineers.

 

Just in top of that there is a "dude" here in my towns province that actually has built 4 aeroplanes with VW engine that are all of his own designs made outa fertiliser sacks with unorthodox controls..has no flight training and several of his planes has been confiscated and he keeps flying. One of the planes is a low wing monoplane without ailerons. One of his kites is in a museum in Jyväskylä.

 

Last bann came when I reminded that we have one existing FAI record made with VL-70 Vinka...a flight from Helsinki/Finland to Odense/Denmark ( 1010 km ) at average speed of 35,4 km/h in 1000-1750 kg class. Next day I also mentioned about an ardent opponent of mine in the net being either too fat for his Fournier 4 or the Fournier 4 was smaller than I remembered..he was doing phony strafing runs in his Fournier 4 in a picture cavalcade...which I considered ridicilous abuse of a motorized glider. I think I earned the bann..so I have no regrets. I am also sorry for the personal "assault".

 

I have never been banned from a foreign site. Also my back is good..I just cycled 50 km last nite and I am under no medication ( for a year and a half by now ).

 

rgds,

 

Juke

 

 

Just kidding !

 

 

[sain]

EAA certified testpilot

I didn't think the EAA certified anything? You might want to rethink making use of that particular testpilot.

 

 

[Guest ozzie]

The EAA did/does do a lot of testing on various designs and STC's ect. For example the Mogas STC.

 

Ozzie

 

 

[topspeed]

I didn't think the EAA certified anything? You might want to rethink making use of that particular testpilot.

Ok I may have misunderstood. He is a member of EAA. He has testflown finnish ac designs previously. Certainly EAA has not educated him or anything that sorta. He has also presented some suspicion about the changes of this ac bringing anything that I have claimed it could. Thence I may reconsider using him as a test pilot.

 

I think my easiest way now is to make a model and see how it flies.

 

My original thinking is very annoying for some of the TKK students who spent 5 years stydyin Navier Stokes etc equations. I may be wrong here...some of the TKK students think I am all right some have doubts..or just being arrogant.

 

For instance if I calculated that the drag of my kite is .34 sq ft and Cessna 172 Skylark has 5.5 sq ft of FPEA ( 16 times more ). It has 160 hp engine and cruises at 140 mph..then I simply assume that when I have proportionally more hp:s per drag and less wingloading in my kite I have to ( be able to ) go nearly as fast or faster.

 

http://en.wikipedia.org/wiki/Cessna_172

 

 

[topspeed]

who would have one ?

 

I was wondering since chief of the TKK flying club Mr.Juslin is actually interested of this design...

 

Who else is interested of a kite that has 200+ MPG and goes 165 mph and costs less than 20 000 usd to build ?

 

economical fast aeroplane

 

That could be handy in Australia when the distances are long.

 

 

[Guest steve woods]

The ultralight

 

I have really enjoyed reading this design process.

 

wondering what is the proposed speed range ?

 

could a VW be used with a pulley (simple and cheap but just a little heavy around 67kg with a hand start)

 

happy designing

 

steve

 

 

[Deskpilot]

Hi Steve, yes a vw would be suitable and as a proof of concept, I would try a triple belt setup. I have also considered a swing loaded switch on each being activated in the event of a belt failure. Three red lights on the dash and you just know you're in trouble.

 

As to speed, no idea at the moment but I'd be hoping for 80+

 

I haven't done a lot with it recently as my wife has been quite unwell and she takes priority. Lots of thoughts but no action.

 

Thanks for you interest.

 

 

[Guest steve woods]

tail plane

 

doug,

 

Sorry to hear about your wife and hope she is on the mend.

 

looking at your diagrams it looks as if the wing is a cantilever design.

 

my question is about the tailplane. all aluminum cantilever or fabric covered chrome moley design or something different.

 

due to flex in the boom i think push pull cables could be worth considering as push rods could exaggerate movement to the control surfaces

 

steve

 

 

[Deskpilot]

Thanks for your concern re the wife. A long recovery after major surgery is expected, not all physical in nature.

 

Yes my wings are to be self supporting cantilever design but removable from stub wings about 2 feet long. Problem is, this only gives me about 3 feet insertion into the main frame and considerable strength has to be built into the spars. Being as I'm using tubes, a separate inner of sorts will be added but I have to watch the weight. I have a few options but will need to do some testing before committing to a final design.

 

On the same theme, I'm looking at inner strength in the boom as well. A thick wall tube will help but the stresses at, and just aft of, the prop hub assembly might cause localized cracking, not a good thing. I have already decided on cable control lines, more for ease than anything else, but I take your point.

 

As for the tail plane, this is in a state of flux at the moment. The original design was to be alloy tubes with plywood ribs and foam infill to give some shape. This would be fabric covered and the whole lot self supporting in that no external bracing is wanted. Built onto its own tube that slips over the main boom by way of slots cut into the main and then clamped and pined at the rear end. Not easy to explain. I went for the crucifix style for 3 reasons.

 

1st, to provide protection from prop strike in a high nose up attitude on t/o and landing.

 

2nd, the plane has to be tail heavy when empty and therefore needs the bottom rudder to rest on.

 

3rd, joining the vertical and horizontal components is easier and stronger the either V or Y tail plane designs.

 

Recently I've been toying with the idea of and inverted Y but can't see it working with alloy tubes. As I said in the beginning, I don't want to result to welding because the average Joe doesn't have that skill.

 

My latest efforts have been in modeling the main body assembly, trying to get something that's reasonably streamlined using flat surfaces, and/or bent from flat sheets. I'll post a new picture when I have it more complete.

 

 

[Deskpilot]

Hot off the press

 

Pictures as promised. The line over the pilots head is the intended canopy shape. His left leg is amputated to show nose-wheel retract position only. I'm not an amputee.

 

Excuse the colours, haven't used my printer lately and the colours aren't mixing properly. To get pictures of my model I have to print the screen and then rescan back to my saved file. Bummer, but it works, most of the time.

 

Boom may be lengthened for better balance and nose-wheel assy is not 3D modeled yet.

 

 

 

 

[Guest steve woods]

the wing

 

about the wing

 

the design of the compression tubes I have nat seen before and why is there a leading edge spar?

 

 

[Deskpilot]

Steve, please read all the posts. This has been explained previously. I have also answered your PM.

 

 

[Guest ozzie]

Doug,

 

i'd look at the over all length, diameter and wall thickness of that rear drag tube to see if it can handle the compression loads for its current location. i would consider shorter and moving it to the inner aileron rib as it's max outboard position on the main spar. do not allow it to contact any rib.

 

Ozzie

 

 

[Deskpilot]

Thanks for the advice Ozzie, particularly "do not allow it to contact any rib"