Strykaas

Hello,

I'm about to start building my micro biplane aircraft, wing span around 0.60 m / 23'' (Christen Eagle or Pitts ...), and I'm looking for a good engine. Basically I would go for an OS10 or OS15 (BTW, is the OS15 not too heavy for such an aircraft ?). I also have the opportunity to buy a MVVS 12 GFS/R ABC RC.

My purpose is to have an easy engine (not necessarily the most powerful). Which one would you advocate ? Are there any other brand in terms of user friendliness ?

Thanks !

William Robison

My Feedback: (3)

Strykaas:

A 23" span biplane with a 0.10 engine is liable to be a rocketship. Or a lead sled, if it's heavy. Are you sure you don't want to go bigger?

The engine? Most all available are good, and should do well.

Bill.

Bipe Flyer

I agree with Bill. A .10 is too much both in terms of power and weight for a 23" bipe. I've attached a couple of pictures. The Ultimate has a 25" span and uses a Norvel .061. The Bipe Stik has a span of 28" on the top and 24" on the bottom and is powered with a Norvel .074. Originally the Bipe Stik had a Thunder Tiger .07. The Cloud Buster (white plane) has a 30" span and used a Norvel .074. All 3 planes have ample power. With the .074, the Bipe Stik has unlimited vertical. For ease of operation and good power I'd suggest about a 26" to 30" span with a Norvel .074 and keep the weight under 25 oz, which should be easy.

Strykaas

Thanks Bipe Flyer for your thorough advice .

I still have a few more questions :

1) Rudder issue : Your Bipe Stick has a rudder. Is it really efficient / useful on such a little aircraft ?

2) For these micro Bipes, can u tell me more about the flying volume needed ?

3) I do not know the Norvel engines (they 're not available here) : Are they glows ? If so, which nitro percentage do they require ? Do they use specific plugs ?

4) How heavy is your Bipe Stick to be able to perform unlimited (and out of sight )vertical ?

5) I've checked out the performance of these eninges :

OS10 LA : 0.27 BHP for 112 grams
OS15 LA : 0.41 BHP for 138 grams
Norvel .074 : 0.38 BHP for 75 grams

What can I conclude from that ? Are these performance comparable (same nitro percentage etc ...) ?

I would think an OS10LA is more powerful than a Norvel .074 on the same nitro %.
What do u think ?



Thanks.

flyinrog

My Feedback: (1)

Hey strykaas, I dont have the experience these guys do but, I agree from what I do know the OS 10 is very user friendly but heavy,, listen to them about wingspan and weight
for your questions
rudder would be needed to assist in manuvers. and ground handling, if you just want to float around you dont need it.

"flying volume needed"? zoom over my head

Norvel, great engine..do a search,, high nitro (25%) fuel (glow) and not standard plug,, uses a glow head like cox (sort of) a norvel .074 is said to have the power of a.10 and way less weight..
I would guess BipeFlyers planes at under 20 oz, but just a guess

Rog

ElectRick

My Feedback: (2)

Bipeflyer,

Where did you get the Ultimate you posted a photo of? Is it scratchbuilt or a kit? If scratch, from whose plans?

Thanks,
Rick

William Robison

My Feedback: (3)

Strykaas:

Your own numbers show the Norvel 0.074 more powerful than the OS 10LA. And unless France has the Norvel on an "Import banned" list you can order one from England or here in the USA. And order some extra glow heads at the same time.

The OS LA series is not high performance, intended for casual sport use. The Norvel is a screamer, it wants to go fast. You have to decide if you want a fast responsive plane with the Norvel, or just to make holes in the sky with the OS engine.

ElectRick:

Contradiction sir. If Bipe's Ultimate is scratch built he did not use anyone's plans.

Bill.

Strykaas

William,

Nope, you're wrong [sm=stupid.gif] . These are numbers from different manufacturers wich therefore cannot be directly compared. On which fuel were the measures perfomed ? (especially nitro percentage, temperature, humidity, measure equipment, propellers, etc...). These numbers were all the more suprising to me as .10 is 133% of .075... That's why I'm asking for your help to find out the real truth.

Yes, in France, it may be not easy to find them. If I failed, I would be obliged to order it from US / UK through my credit card number... Isn't there any other way to pay ? You may think french people are quite apprehensive regarding giving credit card numbers, but you must know that french banks are not always with you here, in France, when something goes wrong, and you often have to pay for a fixed price anyway. This could finally make me buy a MVVS .12 ABC / OS15CVA (micro servos mandatory, for weight reasons) , which are imported here.

Last, what are the Norvel parts I'd better order directly with the engine ? You've talked about glow plugs ... How long do they last ? Which other parts ?

Thanks for sharing your experience !

Bipe Flyer

Yes, just as useful as on a larger plane. Knife edge, flat spins, snaps etc. are all possible.

I'm not sure what you're asking here.

They are glow engine manufactured in Russia. I've run mine anywhere from 10% to 35%, but I usually use 15% or 25%.

20 oz

Bipe Flyer

It's from my own plans. One of these days I'll clean them up and have them printed.

Strykaas

By flying volume, I meant the minimal space needed to fly your aircraft. That's definitely very important to me, because I fly on small fields !

Bipe Flyer

Semantics

They're my own plans, so it is scratch built.[sm=biggrin.gif]

William Robison

My Feedback: (3)

Strykaas:

Horsepower figures, even when they are all from the same manufacturer don't mean a lot, but they do give a relative idea. And in service tha Norvel 0.074 has shown itself to be effectively more powerful than the OS 10LA. This is, granted, partly because it has less weight to haul around.

BipeFlyer:

Sorry, I should have said "Anyone else's plans. We agree on the difference between scratch building and plan building.

Bill.

Strykaas

Thanks William

Japanman

I have built an about 600mm wingspan bipe with a reedvalve cox and a apc7by3. it didn`t go verticle, but it was made of white foam, covered in coloured packing tape and it was a blast to fly- it was so light with so much wing it seemed impossible to stall- and i flew generally right in the deck right in front of me. some of the most enjoyable flying i have ever done- contour flying, 'pylon' around trees, walking speed touch and goes- etc.
I would go with a norvel 0.074 engine- get maybee three plugs with it so long as you don`t run it over lean just one plug should last you forever- my norvel .061 is almost worn out and 4years old.. but i am still running the origional plug! so three should be safe.

J.M

BMatthews

If you are flying on very small fields then you may actually be better off with a slightly larger but lightly built model. A larger and lighter model can fly slower and closer in to the pilot. It also performs tighter maneuvers and lands in less room thanks again to it's lower flight speed.

So rather than aiming for something super small (rediculously small in my opinion) like a 23 inch bipe with these engines I think you are better off to aim at a 30 to 36 inch biplane model. The 30 inch size being for engines up to the Norvel 074 and the 36 inch size being for the OS 10 or 15. Your figures show the OS engines to be quite heavy so they need a larger model with more wing area to carry that weight. I would say that for the 10 you want about 300 sq inches area and for the 15 you would want 400. And a low construction and equipment weight is very important.

For any of these options I would recomend that you use the newer micro servos. Not the super micro parkflyer types as your flying speed would be high for the output torque but the slightly larger size such as the Hitec HS-81 would be good.

Strykaas

Matthews,

I agree with u, but my actual purpose with this aircraft is to be able to go and fly at the end of the day at the nearest football playground by bicycle, taking all my gear into my back pack, including the aircraft ... As a result, big airframes are irrelevant [&o] !

Bipe Flyer

How about a 38" span biplane with a Norvel .061? The blue bipe with tan wings in the first picture and the red with white wings in the second are models called "Old Bill". It's an excellent flying rudder/elevator/throttle design which can fly very slow and yet has enough power to loop.

MR Flyer57

When you get them finished, I want a set! All your plans are great, and I think that is the best plane you've made so far.
You'll have to get the next contest started, weren't you were planing on doing a GEE BEE until you opted for the ultimate?
MR Flyer57