Microlighters

Hi all micro lighters,

I am still a land lubber microlight wannabe at this stage. For several years I have been eyeing you guys in the air enviously. A couple of things have kept me on land. The noisy motors and high fuel consumptions.

I am bringing in an electric powered off road bike, the Blade XT, soon for distribution in SA. This bike has a 29Hp & 55 Nm that should make it work in a microlight. With two Lithium Ion battery packs and one motor the weight will be similar to a normal petrol motor with full fuel tank. Flight time should be at least 3 hours with the two battery packs. The system has been in development for 10 years & has proved to be very reliable.

Necessity is the mother of invention so I am looking for some interested parties who may be interested n helping me develop such a machine.

All I need is to purchase a good machine minus its motor & fuel tank, a Stealth propeller and a team of enthusiastic helpers.

You can find more info on the bike at http://www.wildsands.co.za/blade_tx3.htm

Any advice, ideas or volunteers??

J Bax (Durban)
083 788 5636
jbax@wildsands.co.za

Me thinks 29 hp is a little on the light side ..... My Rotax 503 has 52 hp (up hear at the reef 43hp).

She'll definetely be a single seater and not di=esigned for big okes. :D

Welcome Stealth and hope you get flying real soon.

Electric angle @ 29hp sound interesting... but I spose the skeptic in me will wonder if it will have the kind of output in terms of power/torque & responsiveness, etc to hack it for flight

Probably not be viable for going too far from the home patch from a recharging point of view

Could be an option if your going to fly some kind of solo hyperlight, low level over a large flat open spaces

We sort of look at Rotax 503 (50hp) as being the absolute Minimum nowadays for reliability, output, etc and it will lift most dual microlights

But then the Otto, Wilbur and Octave all managed to get larger, heavier ships up in the air starting with just 9hp and later settled on the formula in region of 50lbs/hp back in 1900)
... so with your 29horses and modern technology you should be able to lift at least 1450lbs/657kg which is way over the legal microlight limit of 450kg :D

Trike seems obvious answer, but nothing stopping you looking at a whole serious of fixed wing machines, all mfg will likley supply planes without motor and the gubbins, but will need you to do the weight & balance really carefully again im sure

Good Luck !

Thanks for the positive feedback. As a matter of interest, what is the torque of the rotax motors? The electric motor has 55 Nm and the torque curve is totally flat, in other words, max torque is available right from the begining. Also an electric 29Hp is probably equal to the 50hp of a petrol motor in real terms.

I think that this motor will do just fine for a solo flight. I don't have a problem with that as it is the birth of a new concept.

The aim of the exercise is to get the concept off the ground. If I can successfully do that, I am sure I can get the chaps at ElectricMoto to develop a more powerful motor if need be. Range is also not an issue as this will be a prototype. A three hour silent flight will do me just fine for now.

What I really need is someone who can advise me on what machine will best be suited to this appication (As light as possible solo machine - but strength must not be compromised) and someone who can supply me with such a machine. Even better would be to also find someone to help me put it all togeather.

First Dieselfan with his diesel fantasies and now Stealth with his quiet lectric plans.

The idea is very intrigueing! I would like to see some more of it (just out of curiosity)

Best I can suggest is to visit as many fields as possible and check out all the undercarriages out there!

Stealth,

Could you give me an idea of the weights of the motor and the battery pack? Also what would the price be?

I have different application and only need to get to 2000' - You know some of us don't like noisy engines!

Stealth wrote:Also an electric 29Hp is probably equal to the 50hp of a petrol motor in real terms.

Hi Stealth,

How do you figure that 29Hp = 50Hp?? Remember, you are talking about “after the internal inefficiencies of both are ruled out” because Hp is a measured output.

What you could be considering is that 2-stroke power bands are found at some 5 000+ rpm and that with the g/box reduction, the propeller ends up being only some 4% efficient.

Junkie wrote:Trike seems obvious answer, but nothing stopping you looking at a whole serious of fixed wing machines.

Now Junkman, Trikes are the meanest drag creating inefficient flying machines ever built or designed – but I love mine !!!

Lightweight fixed wing should first be considered by Stealth - something like "Miss Behaving" [below].

Regards
John ZU-CIB

John Young wrote:the propeller ends up being only some 4% efficient.

S*** That's even less efficient than the most inefficient beast of all - the steam locomotive.

Electric power is an interesting proposition, though. Stealth, how about getting a slightly LESS powerful and much lighter motor and trying it out on a Doodlebug (supine paragliding harness and hanglider wing...) That engine, the Radne Raket, is just 14hp, iirc.

Rooikat

This is a tricky question to answer mathematically. All I know is that you take a 500w electric scooter (with the correct controller) and dice it against a 2 1/2 hp petrol jobbie and the electric eats it in acceleration, up steep hills and in towing power.

The Blade XT MX bike only has one gear and can hold its own against a 30 Hp 2T mx bike. Put a gearbox on the XT and the 2t will only see dust.

Maybe the combination of the flat torque output of the electric motor combined with the Hp output makes it that much more powerful. As for props, I have no clue; I leave it up to you guys to advise me on that one.

All I want to do it to put this baby together, balance it out and try it out. The proof of the pudding is in the eating.

The motor is less than 10kg and the batteries are about 30kg each.

Why do you guys keep advising a fixed wing???

All criticism and ideas are welcome.

JP

Stealth wrote:This is a tricky question to answer mathematically. All I know is that you take a 500w electric scooter (with the correct controller) and dice it against a 2 1/2 hp petrol jobbie and the electric eats it in acceleration, up steep hills and in towing power.

Simple My Dear Sherlock – it is called “bottom-end torque” – a 2-stroke engine has no bottom-end torque to speak of.

Stealth wrote:Maybe the combination of the flat torque output of the electric motor combined with the Hp output makes it that much more powerful.

Not more powerful – just more bottom-end torque.

Stealth wrote:All I want to do it to put this baby together, balance it out and try it out. The proof of the pudding is in the eating.

You will do a lot of eating all right – that is eating a lot of grass chin first!!

Stealth wrote:As for props, I have no clue; I leave it up to you guys to advise me on that one. Why do you guys keep advising a fixed wing???

Stealth – my assumption is that you are an eager young man with a healthy dollop of ambition. Good. Bum lifts and go to as many airfields as you care to visit and look, and ask as many questions as you can. Why do the fixed wing aircraft with 582’s substantially outperform flex wing?? Borrow books and take up an offer of the odd flip. Etc. Etc.

Email me - I will be happy to exchange details and give you the odd lift to the airfield.

Good luck.

Regards
John ZU-CIB

so what about two of these motors feeding a single gearbox to give a combined 58hp? with an endurance of 1h30?

That should do the trick...plus an additional battery that will give 10 more minutes in an emergency.....

just think of the stealth neighborhood watching you could do?

The concept is great, and works just fine. There is already one production aircraft using only electric power - a self launching glider. Uses a synchronous motor and LiIon batteries.

I have quite a bit of experience with this for RC aircraft, with a number of electric setups in the 1-2hp range. I also have the software tools to do the prop matching for max efficiency. If you can send me the motor and battery details, I could do some prop matching for you, and let you know what is possible.

Sounds like fun!

-justin

Oh yeah, you don't have to worry about the batteries going flat. LiIon batteries have a VERY predictable discharge. It is easy to add a battery monitor that will let you know (a) how much battery time remains at current power levels and (b) how much battery time remains at full throttle.

Much more accurate than fuel gauges .

-justin

Ah ha, thanks for all the feedback chaps. Things are hectic getting the holiday stock. ready. I will contact you all individually soon. At the moment I am gathering as much data as I can and with the right team we can start to put things togeather by June 2007.

Keep the advice rolling in.

Thanks
JP (Stealth)

How about fitting some bicycle type pedals with a battery charging system, when the bat gets abit low you can trap like mad and recharge.....unlimitted airtime........