UFO Helithruster

[aussie_paul]

True Paul.... with vehicles, they prolly do fuel consumption testing on dynos or "theoretically" and in certain conditions with people trained to drive as frugally as possible with blueprinted engines on fuel to a perfect grade with the first prototypes.... I bet when the production models start getting driven on the street by Joe Average, they don"t get anywhere near the supposed fuel consumption.... same for emissions

[gyroo]

Yeah - fuel consumption figures!As the owner of one of Jeff Henley-Smith"s as yet un-run Italian Simonini Victor 2 Plus 2-stroke engines - supposedly 102 hp - and with "published" figures of 82hp at 5400rpm burning 9 litres per hour, although I"m not a member of the Australian Skeptics Society I reckon I just as well should be because I scoff at those "published" figures.Perversely, unlike most engine owners who want to talk down their fuel burn, I"m actually looking forward to seeing how much fuel the Victor 2 Plus will REALLY consume!

[gyroo]

Hi Browny,Are you speaking from experience with one?Mark R

[RossM]

My latest creation has an 80 litre tank, simply because the Westach fuel gauge I"ve got has 16 segments on the 270 degree sweep dial - 1 segment equals 5 litres - in Meerkat language "Simple" (and, yes, before you all start at me - the tank is completely symmetrical and will drain evenly from top to bottom).Mark, HobbyCAD from Hervey Bay posted on RotaryforumI had to purchase 2 senders to achieve a PERFECT linear reading. This is what you do:Go to the Westach Instruments site, or speak to Pete at Westach, tell him Francois at Seabird referred you. They have capacitive senders in LONG lengths. Get one that will go all the way from the top to the bottom of your seat-tank, even if it bends down to the front, to hit that low spot. You purchase a longer one, you can cut the end down. Order one with no alarms, a stock one with linear output, 0V to 5V. Install it into your tank. Connect a 12V power supply, and a multimeter to the output. Now, liter by liter, add fuel, and take the sender output reading for each liter you added. Do this until it"s full. You will then see the voltage output is not linear. Send this table to Pete. He then programs you a sender with a correction table, so that the output becomes linear, for that response curve you sent him. This is the second unit you must buy. (Sell the old linear one). For the second custom calibrated unit, you can order it with an alarm output, you can select when. I have my alarm trigger at 12% remaining.With this custom response table sender, your output will be a perfectly smooth 0V to 5V in equal steps from empty to full. Perfectly linear response !! Not the cheap 5-programmable-point stuff, this method can have hundreds of points.I don"t know what you will be using as a gauge, but there are a lot of 0V-5V instruments out there. Go for a 270 degree arc display, not the cheap 80 degree stuff. With a 270 degree arc, you can clearly see where your fuel quantity is.So you can calibrate a fuel sender to make the gauge perfectly linear, no matter what shape the fuel tank is.

[gyroo]

Well spotted Ross,but you"re assuming I"m using a seat tank, which I"m not. The tank is a high box shape 24 inches high, completely symmetrical (ie the cross-sectional area doesn"t change from top to bottom). No need for the double sender method.Mark R

[Brian]

I always love listening/ watching fuel figure talk & hearing what others are getting etc & from a well calibrated fuel flow meter plus putting fuel into the gyro from a pretty accurate fuel meter I can say that my Rosco 2.2 suby average over 12 months was 16.5 LPH. Best I saw on the fuel flow meter was a 13.7 for about an hour & the worst tank full was 18 . something, shocking air & was struggling to breath let alone fly

[gbw]

While you guys are on fuel economy, might I ask why gyros do not have small wings like a Cartercopter. As speed increases, the wings would develop lift which would mean the rotor did not have to "lift" as much, so the disk would flatten and provide less drag. The Cartercopter has more tricks up its sleeve, but it is chasing much higher speeds.Graham

[MadMuz]

While you guys are on fuel economy, might I ask why gyros do not have small wings like a Cartercopter. As speed increases, the wings would develop lift which would mean the rotor did not have to "lift" as much, so the disk would flatten and provide less drag. The Cartercopter has more tricks up its sleeve, but it is chasing much higher speeds.Graham Graham, as you prolly know, the enemy of gyros is unweighted rotors.... anything less than .5G is dangerous.... so gyros as we run them need to stay at around a G (positively loaded) Therefore, any "lifting surface" such as small wings that carry weight, will reduce the loading on the rotors, so therefore, for us they are a no-no... Carter are not building gyros as we know them, not to mention they are having a lot of issues.... I don"t know how they are approaching their attempts, but a guess would be when the wings take over, the rotors must be reduced in pitch so they are letting the wings carry the machine and it would be my guess that the rotors are driven as opposed to autorotating, because autorotating rotors would slow down and lose their rigidity once the wings are doing their thing..... Our style of gyros with 2 blade teetering rotors could not do what they do if wings were added, or even lift from a cabin design could unload them... IMOGyros are gyros.... they are slow (in the aviation world) and draggy and will prolly always be so.... I like them just the way they are, personally

[Tim]

I recall a pilot at a national championship at Lameroo a few years back. He had an enclosed gyro with a 4 cyl Hirth 2 stroke (110 hp I think). He was ecstatic after the "economy exercise" when at most economical slow cruise he only used 27 Lph. When asked what it is like at high power settings he replied "ouch".There are those that subscribe to the theory that in any given efficient petrol engine, to do the same work, it will use

[gyroo]

Graham, as you prolly know, the enemy of gyros is unweighted rotors.... anything less than .5G is dangerous.... so gyros as we run them need to stay at around a G (positively loaded) Therefore, any "lifting surface" such as small wings that carry weight, will reduce the loading on the rotors, so therefore, for us they are a no-no...Dear Muz, I beg to differ with you on this one. It"s not at all the same thing as placing a rotor into reduced-g by part-bunting over or nosing-over at

[gbw]

"In other words, I don"t see much of a dynamic hazard associated with fitting stub wings to a gyro to relieve 1/3 or slightly more of the gross weight from the rotor."Thanks Mark, and Madmuz. The early gyros were basically airplanes with a rotating wing on top. In the main, they have evolved to a pusher prop with the bloke hanging from the rotating wing. In Carters version the pitch is reduced on the rotor as speed increases, and the wings provide more lift. To me it seems people have concentrated on manoeuvrability. For cross country stub wings would seem an advantage, as with the current form, fuel economy seems very closely linked to weight.Graham

[MadMuz]

Mark, I think you will find that if one of our teetering 2 blade gyros had wings that could relieve the rotor of 1/3 of the weight of the machine, the rotors would slow down as they are carrying less weight, then the machine is pushed faster than normal with the disk very flat, turning slowly with less rigidity, the rotors flying into any downdraught (or the wings copping an updraught and taking more off the rotors) would be disasterous?

[gyroo]

Hi again Muz,I reckon it"s much more a question of whether its practical as distinct from whether its hazardous. I agree that the slowing of the rotor would need to be accompanied by having a highly tip weighted rotor along Magni lines but with a much heavier set of tip weights. Carter has extremely heavily weighted tips for his slowed rotor designs.Why I"m commenting on practicality is because one needs to consider the extra structural weight and additional parasite drag with any stub wings, as well as the heavier rotor weight due to heavy tip weights. Also, it would be not much help installing stub wings like a Bell Cobra had because the very low aspect ratio would lead to high induced drag, and so any efficiency gain achieved from slowing the rotor and having it operate at a lower disk angle of attack would be lost by the overall drag increase caused by the supplemental wing and the extra structural weight.Carter has chosen to opt for high aspect ratio wings in his designs and I"d bet quite a few bucks on the probability that he found out quite early that he needed to have high aspect ratios for the slowed-rotor and supplemental wing combination to be in any way competitive against either a wing alone or a rotor alone. I remain entirely unconvinced that Carter"s research is going anywhere, but I guess it"s important to have research projects like his going on for the sake of pure research. Like you, I"m strongly of the view that supplemental wings on our small and light machines simply wouldn"t be worthwhile or practical. I completely agree with you that the best and simplest lifting mechanism for our gyros is a rotor alone.I only jumped into this digressing thread because your earlier post made mention of the hazard of reduced-g with teetering rotors, which is not precisely "on-point" in any discussion about slowed rotors and supplemental lift devices. I can see where you"re coming from, but I don"t share your apprehension about the level of potential hazard. After all, our rotors transition through stages during takeoff and during landing where they are only producing 1/3, 1/2, 2/3, 3/4 etc the amount of lift needed for the machine to be airborne, yet the rotors respond "normally" during these transitions (other than in a high-speed rotor-flapping incident - but that"s caused by a different process yet again).Cheers,Mark R

[mad max]

Just back from Auckland checking the new UFO now called a Sky rider with a Suzuki Hayabusa 1340cc M/C engine with Patrony prop. A UFO cabin with carbon fibre tri tail. I found it will comply easy with the 600 kg weight limits allowing for two big beaf eating ausies (and a petite blond between them.) During a test flight with one up the 90 kg pilot never went to full throttle. More info. and photos shall be posted at a later date.

[MadMuz]

That"s great Max, I look forward to seeing those pics