Little wing Autogyro

[asra]

Is any one out there building a Little wing Gyro. I've just started on a side by side version (my modification)and I would like to hear from other Little wing builders. DarylDaryl Patterson

[asra]

OK Daryl, sounds interesting, what are you going to use as fuel tanks and a powerplant? What is the overall width of the fuselage and what is your intended length from the firewall to the rudder tip? I have been looking at something similar but to keep with the asthetics of the traditional machine, I believe 4100mm is not long enough. I have nearly completed a SupaPup (and that has been an experience)and the construction layout is similar and 4800mm in length. I understand the two seat version is longer again.Best Regards

[asra]

The fuselage will be 850mm wide at the top and bottom and 1000mm at the middle frame (similar to a skyfox). It will be 100mm longer than a LW5 (from the firewall back)because it will be powered by a Jabiru 3300 (maybe Subaru). The tail surfaces will be increased in area and made in a slightly different way. The fuel tanks may be two 40 litre seat tanks (I've got to get their dimensions) It probably quicker to say that at this stage only the undarcarriage is interchangable with an LW5. Its also going to have the mother of all prerotors ( probably hyraulic unless someone knows of a soft start starter motor that will spin a set or rotors up to atleast 200 rpm. I have the capability, it's the money that's the problem (the wife wont get a second job).Daryl Patterson

[asra]

Daryl, I just went out and measured my Jery Goodwin seat tank, it is 17" or 430mm wide, slightly narrower at the top and front.May I suggest that the Jabiru is not a good choice? Being direct drive and being obliged to run a smaller diameter prop it is best suited to fast slippery craft. I don't think any of us will be able to claim that for our gyros!Don't forget that the thrust per HP is greater with big diameter props.It's great to see more people going tractor, while it has its own set of problems, I think they are less than what we are seeing with the big pushers.John EvansThink logically and do things well, think laterally and do things better.

[asra]

Well I am glad someone else came forth with that. A Jabiru was tried unsuccessfully in Qld although it was a cooling problem being a pusher, it also couldn't get the thrust up being a direct drive. I seriously believe you are going to have to look for an alternative.Best RegardsBarry FergusonHirth DistrubutorAustralia & New ZealandPh (07)5464-4993Int +61 7 5464-4993

[asra]

Thanks John and Barry. That's the main reservation I have about the Jabiru engine. I like the Jabiru for its simple design (and its about 35 kg lighter than a Subaru). I'll soon find out the static thrust of a Jabiru 3300 and compare it to the Subaru. The 4 cylinder Hirth is an outside chance, but a lot of people hate the sound of 2-stokes. I better make the fuselage a little bit wider.Daryl Patterson

[asra]

Ron Heron uses the F30U (carb model) on his LW, he said it was an engine ideally suited to the application however, being a free air installation, he said it took him a while to get used to and feel comfortable with the higher temps. I'm not sure yet as I do have to locate some better pictures of the installation but I am positive the high temps are due to the cooling shroud design used. I also believe the detuned model, the F30K (none here in Australia) or the F30E (three here in Australia) would be a better choice due to the very flat power curve. It also runs a lot cooler and very smooth through the power changes. Daryl, it really doesn't sound that much like a two stroke under load or a cruise and more like a powerful outboard engine when idling. I was a VW person once but I have no problem with this beast.RegardsBarry

[asra]

Thanks Barry. When I check the Hirth website is said up to 110hp but the F30ES is rated at 102hp? Has anyone measured the thrust produced by a F30 ES? What is the installed wieght of a F30ES.I have 700 hours of ultralight flying, mostly behind a 503. I have no problem with 2-stokes but most people seem to hate the sound. When I started in Ultralights a lot of people thought I had mental problems. Now that I tell people I'm getting into Gyros they shage their heads and try not to make eye contact. I want to do my bit to promote Gyros without giving the more ignorant people in aviation any more excuses to hate Gyros. Daryl Patterson

[birdy]

Don't suppose you'v concidered a 4banger rotax Daryl???I almost put a 3300 jab on me RAF,till I heard bout the cooling problems.If there wasn't a visability problem with the tractor setup,I'd use one for mustering.Ignorance is bliss............but only till you realise you were.

[asra]

Thanks Birdy. The 912 is a good engine, but a 3300 Jabiru is priced between the 912S and the 914 with more HP that both. I still need to find out the thrust it will produce(if Jabiru can't tell me soon I'll find out myself). 3300 Jabirus aren't rated at max power continuously (unlike the 2200). I suspect because of cooling issues. Partly because of less than optimum fuel mixture control (which they appear to be getting on top of) and simple having a heat dispensation problem. This is a laws of phyisics thing not an instillation problem. A 3300 in a pusher configuration at this stage of its developement may be all a bit too much. This is all just my opinion.Why do I want 120HP? I designed me present aircraft to take a 912. When I stopped work to become a housewife the budget went south, so I installed a 503 (saving $10,000). Three years latter my wife wanted to sell our suburban house and shift to a small country town and renovate a bluestone church into a house. I took my eye off the ball and the next thing I know my morgage went from $0 to $300,000. I often think about the $10,000 I saved. I wont get fooled again.Daryl Patterson

[Tim]

Daryl, even though the Jabiru is a good engine, it matters little what horsepower it can produce if it cannot transfer the HP into thrust required for a low speed aircraft like a gyro. The only way to do this is with a slower turning large diameter prop,(reduction drive). To achieve its horsepower the Jabiru needs to spin to approx 3200 and at that speed they are limited to a comparatively small prop of approx 55" in diameter.Tim McClure

[asra]

A simple 'rule of thumb' for calculating prop rpm and diameter is to use the constant 201,655. If you divide either the prop rpm or diameter in inches you will get the other. It's just a rough guide on what will work, and will vary with things such as the thickness of the prop blade, the air passing over the cambered surface going transonic earlier on a thick blade.Did you know that the term 'rule of thumb' was originally to do with the the diameter of what you were allowed to beat your wife with? i.e. nothing thicker than your thumb.[]John EvansThink logically and do things well, think laterally and do things better.

[Tim]

Crikey, a 3/4" iron bar could do some damage.Tim McClure

[asra]

You're a brute Tim McClure!What they don't tell us is what happens to us when we try to comply with this rule. I don't think there is any thing governing what we can be hit with!John EvansThink logically and do things well, think laterally and do things better.

[asra]

A simple 'rule of thumb' for calculating prop rpm and diameter is to use the constant 201,655. If you divide either the prop rpm or diameter in inches you will get the other.John i'm obviously behind the eight ball abit here, but could you explain that part of your post abit more pleaseMark