Motor bicycling taken to a higher level

Discussion in 'General Questions' started by Fabian, Jan 4, 2014.

  1. Fabian

    Fabian Well-Known Member

    Now this is motor bicycling

    Last edited by a moderator: Dec 15, 2015

  2. Fabian

    Fabian Well-Known Member

    Jim, what sprocket set do i need to order from SickBikeParts to enable the shift kit to operate the lift fan system?
  3. keatonx

    keatonx Member

    The one with the built in flux capacitor!
  4. HeadSmess

    HeadSmess Well-Known Member

    using the coanda effect is a far more efficient lift production than trying to counteract weight with sheer thrust. plus you have some type of wing for when it all goes wrong. i thought i was onto something when i thought of it as a kid. beaten. as usual :( been done waaaaaay back.

    VTOL has never really been a huge success :( yes, helicopters and hawker harriers, etc... but one, its considered the most dangerous maneouvre to perform in an aircraft, and two, its the least efficient. a chopper uses a lot less fuel by taxiing and taking off like any other aircraft.

    of course, as you use fuel, the payload decreases so you use slightly less...

    i do admit, what with GPS and fancy puters and all that...the idea of flying cars becomes semi feasible. restricted flight paths, all aspects of the flight being controlled by a computer, with absolutely NO operator intervention, other than to select destination.

    otherwise...we would have people slamming into each other constantly. they say the road toll here of a mere 8 or so people annually is "horrific" and "avoidable" if people just did the speed limit :jester:

    travelling at 600km/h, head on at someone else doing 600km/h... by the time you can tell if their ABOVE you, BELOW you, to the LEFT OR RIGHT... or directly in front...theres no time to react! at least when your on the ground, with a lane marker...theres really, most of the time, only one place a vehicle can be. they cant be above you. or below you. so, unless theyre asleep drunk or stupid, they must be to one side of you!

    get into outer space, travelling at 100,000kmh+....well, all this star wars footage of flying through an asteroid field may look good on screen...reality you would be dematerialised instantly :eek: every minute, youve basically travelled across australia, if not the world... every second is a few hundred kilometres... can you tell what way something 200km away is travelling? better be quick! be there in a second to find out! halve that if theyre heading directly at you!

    oh, and at 100,000km/h... a brick would need as much power to stop or change direction as it would if say, the titanic was doing 100km/h... thats inertia for you.

    those calculations they make for space flight have to be SPOT ON, you simply cant carry enough fuel to be able to correct course all the time.
    everyone from uri gagarian ill say micheal collins cus everyone forgets about poor old mikey, but rants on about buzz and neil... were completely insane to have put their trust in those machines! but, it was worth it i guess.

    dont get me wrong! i would LOVE some type of little "flivver" i could zip under the radar on! the nearest beach is 10km away in a straight line! its 70km away by road!

    but this video is just another example of someone with a LOT of money throwing it away with no real concern about the final results...
  5. HeadSmess

    HeadSmess Well-Known Member


    now pedal powered planes....are just feasible.

    strap on a dinky lil RC motor and i guess you could call it a motor assisted aero-cycle :)
  6. keatonx

    keatonx Member

    There's no way a HT will make enough thrust with the air blowing downwards like headsmess said cuz the thrust bears all the weight instead of wings. But I thing MAYBE a ht might work in a plane/powered hanglider
  7. HeadSmess

    HeadSmess Well-Known Member

    there were quite a few ultra lights that got up in the air with just a lil victa 160cc lawnmower engine...with a few tweaks of course ;)

    and only early in the morning, mid winter...
  8. keatonx

    keatonx Member

    I'm actually considering, for a crazy experiment, making a tiny plane, powered by a lawnboy 2 cycle mower engine that I have (6.5hp), that sits upon a cheap inflatable tube/dinghy. With a wingspan of around 15ft (long wings, and I'm only 115lbs) Made out of wood and the wings would be corrugated plastic (the stuff they use for lawn signs and stuff) screwed into a wood frame. I would use on the lake at my cottage (hence the dinghy), and would fly not more than 8/10 ft above the water so when (not if) things go real bad I just fall a few feet into the water. Of course this sounds really dangerous! I'd definitely make a steel shroud around the prop, or just make it a ducted fan and put a steel grate over the inlet and outlet.

    Another thing is that before I even install the engine, I could hold onto a waterski rope and get towed by my family's boat, to see if it will even take off and be stable in the air in the first place.

    If I ever actually do it I would only use it once, a meter off the water, fly in a straight line, get a nice video then park it.

    Be easy on me now, it's just a crazy daydream I've had for a while :jester:
  9. HeadSmess

    HeadSmess Well-Known Member

    look into "ground effect" vehicles.

    russians made a monster of a plane using the basically just "skims" above the water. no, not a hovercraft.

    and not quite a plane, either! they wont get much more than a few metres off the ground. very short stumpy wings, they "trap" a pocket of air under there. inverted tips and all that sort of stuff.

    ive seen one "flying" down on the river near me. homebuilt. try youtube, the commercial kit looks pretty fun!

    and FAST. read, water cops dont stand a CHANCE, especially on rough water :jester:

    be very careful. flying is awesome, the FAA or NOT. hence why one must stay "under the radar"
  10. darwin

    darwin Well-Known Member

    HeadSmess ever hear of the V-22? If not bing it.
  11. HeadSmess

    HeadSmess Well-Known Member

    yep, the big tilt rotor type. its not the only one.

    still suffer the same problems as every other VTOL...a lot of power required for it! vtol, is, as any pilot will tell you, extremely dangerous, especially if youre in a confined space. air starts doing a big vortex around the blades, and uh lift. kick up the collective, air flows faster, until the blades stall... then weeeee! down you go! uncontrollably. smack, bang, splat. those blades do a lot of damage when they hit things! argggh! black hawk DOWN black hawk DOWN!!!!!

    and just like a helicopter...they use a lot less fuel when taking off from a runway in the usual speed up then pull back on the stick...

    now a catapult, like on a carrier....oh yeah baby! launched! hope the afterburners are working and you got full power as you go over the edge!

    it was off an aircraft carrier that they first discovered, by accident, that the ejection seat worked under water. LT. Macfarlane, 1954, in a wyvern. throttles died on him as he got flicked off...

    a lot luckier than one of the earlier test pilots, P J Page, who was fired out at 400MPH from a meteor in '47... well, he survived... with a broken neck, legs smashed up, etc etc etc... he had to go down with the seat, as he couldnt run the risk of freeing himself, and having his personal chute tangle up.

    and lastly, id rather be in a helicopter when it loses engine power than any other type of VTOL. autorotation. you can still land quite smoothly with no engine in one!

    the v-22...what happens if all power is lost while the rotors are vertical? you cant even glide then... how do you tilt the wings back?

    (same way actually, they have collective pitch control, so ok...if the blades are halfway between the two positions and you lose power...)
    Last edited: Jan 4, 2014
  12. Fabian

    Fabian Well-Known Member

    The V-22 is an awesome piece of engineering. Shame about it's unreliability issues, and the fact that it can't autorotate, and the fact that if the the drive shafts suffer mechanical failure, you are pretty much dead, and the fact that it costs over $100 million per aircraft and the fact that it killed a heck of a lot of people in testing and the fact that it is a horrendously expensive aircraft to maintain.

    Those small things aside, the V-22 is an awesome piece of engineering with great capability.


    It's been done before at a fraction of the cost; quite possibly with greater reliability and service intervals and increased payload if scaling up the design.

    Last edited by a moderator: Dec 15, 2015
  13. HeadSmess

    HeadSmess Well-Known Member

    i thought of this when i was eight years old....

    unfortunately it was patented a long time before i was even born, so... cant even claim simultaneous creation :(

    but the freaking thing works! and note exactly where the propwash goes. it is NOT lifting directly from "thrust".
    Fabian likes this.
  14. Fabian

    Fabian Well-Known Member

    Crikey, that is a terrific post HeadSmess. I love Formula 1 for the aero side of things as well as the many other innovative systems on the cars; Coanda exhausts being one sneaky trick to get around reduction regulations.

    Even though the Coanda effect is put to good use, it's interesting to note that he uses vortex generators to assist flow attachment over the control surfaces.

    This video is a great representation of non axial airflow creating lift through the Coanda effect:

    Last edited by a moderator: Dec 15, 2015
  15. HeadSmess

    HeadSmess Well-Known Member

    well im 31 and it took me that long to get round to making this...

    PICT0192 (Small).JPG

    i was drunk :) it became a keyring.

    but yeah...i always pictured high speed compressor type turbine, storing in a torus. let the air escape through the thinnest slot possible over the large disc, but with two contra-rotating turbines... converging airstreams creating thrust in one direction... all nicely shaped for maximum aerodynamics and so forth. use the fact that the air will be spinning.

    iunno. all i ever really did was make some nozzle for the aircompressor that will lift a kilo or so...but thats bernouli...

    might do it one day ha ha.
  16. Fabian

    Fabian Well-Known Member

    HeadSmess, maybe you should have a quiet chat to Adrian Newey. I am sure he would be all ears!!!
  17. HeadSmess

    HeadSmess Well-Known Member

    i came to the conclusion, about 10 years ago, that coanda effect isnt that great.


    my nozzle for the can lift simply because the "jet" is in the centre of a 6 inch disc.

    high speed air, low pressure. you create a very thin layer of high speed air, that then "sucks" whatever is being lifted to the flat surface, despite having air escaping from that nozzle at 100psi. (whatever airspeed that is on a 1.2mm nozzle, someone else can do the maths and figure out). its a proximity thing. more than an inch or so clearance and the airjet simply pushes anything away.

    same deal as trying to lift paper off a desk by blowing under it... just keeps sucking itself down.

    hang on...just like a carby throat and jet! :jester:

    anyway. coanda effect...high speed fluids will stick to a surface. i learnt that lesson all too often while brazing...get the torch the wrong way on a piece of steel and the flame would cling to it and come back, hit you in the face or hand or something... as akin to plain simple blowback, the coanda effect was a curiousity. took a long time before i found out what it was called. yep, science teachers sure know a lot... ha ha. half have never seen it before, half dont care... strange, tis what happens with a decanting rod...

    but... theory says its moving fast, so it should be low pressure?

    exactly correct, and exactly WHY it clings to the surface.

    the atmosphere pushes DOWN on that low pressure layer of air. if it was upside down it would push up. etc etc.

    the atmosphere plays the same role as the disc with my aircompressor nozzle.

    the atmosphere, unlike my disc, is not solid and inflexible, but simply keeps moving in relationship to whatever surface this high speed layer of air clings too.

    therefore the atmosphere will push down on the "coanda film" for want of a better name. lift. once again, any old shape section of wing will FLY, with the correct angle of attack, the ideal shape is just, well...ideal... :p but it has to move through the air. as do heli blades, gyro blades, etc...

    coanda does have some effect, reduces the amount of thrust required... but wont ever achieve complete unassisted (downthrust of propwash) lift. as i always liked to think, just lower the air pressure more than normally so across an airfoil? and the thing will produce more lift?

    nope. doesnt work :( air pushes down on the layer with as much force as it pushes up on the underside.

    thats the conclusion i came to.

    laminar flow and turbulence and thickness of layer, surface tension, sure theres a lot of factors come into play, but...

    that video i found is awesome :) makes me dream again despite knowing its pointless.
  18. Fabian

    Fabian Well-Known Member

    You need to have a quiet chat to Adrian Newey. His opinion may be somewhat different.