Avaiojet

I'm being offered much advice on engine choice for my scratch built C-101 project. I appreciate that. Thank you, to all the modelers who have offered suggestions and help. In many other areas also.

Seems as though the Gold 44, highly recommended BTW, could be an excellent choice for this size model. The model is small, with a span of only 46" if scale, and 50", if I choose to cheat a bit.

Keep in mind the short fuselage at 56".

The question is:

Who is flying the smallest model using the Gold 44?

My interest is wingspan, total weight, wing loading and obviously, performance.

Thanks in advance,

Charles

thunderchief

Charles ,
What is your wing area?
Glenn

Avaiojet

Glenn,

I never did the math, but I will tonight. Quick guess would be around 360 to 380 sqs.

Thing is, I see no reason to factor in the area of the fuselage between the root cords.

Charles

Jgwright

Charles

I have probably had the most number of MW44 powered models. The smallest was the FW Ta183 and that was 38" long and 44 " wingspan. The plane nearest your planform is the L39 Savex. This is 48" wingspan and a superb flyer.

These 2 videos will give you a good guide.

http://www.youtube.com/watch?v=95cB9qXflLk

http://www.youtube.com/watch?v=Bc2pmSFVdVA

John

rcguy!

My Feedback: (69)

My R44+ has almost 1,000 sq inches. Alan Cardash Nano has 913 sq inches. "Depending" on subject....750 sq inches is a minimum I would go. I had a R44 at this size and it was "twitchy".

Dave

Avaiojet

John.

Thanks.

I certainly would like to have the spicifics on the L-39 pictured in that vedio? If this is your model please tell me the math.

Wing area, and overall total weight will be fine. At least a beginning.

Could well be the parameters to which I could follow. That model could also help in the placement of the turbine and related items.

Does "resemble" the outlines and moments of the C-101.

Charles

Jgwright

Charles

Sorry, I do not have the model any longer, but the weight was 9.5 lbs dry. The lightest for the L39 with MW44 is 8.5 lbs. You should be aiming for around 9 lbs. I had 3 of these planes over the years and they all flew great. With the latest gold they are a little overpowered. There is a massive thread on this combination http://www.rcuniverse.com/forum/m_13...63/key_/tm.htm . You want to keep the engine as near C of G as you can and have the fuel tank just in front touching the engine. In practice with small planes this usually means the C of G is near the engine starter so that the difference between empty and full fuel does not upset the flying too much. Use a Wren single walled pipe to save weight. The lightest strong retracts are Springair and you want some light tyres. The only thing that will increase your weight is brakes (which we do not have to fit in the UK). However there are some small light weight brakes about. I would use wire legs as they will save weight and stand a lot of punishment. Dont be tempted to fit huge fuel tanks, We used to fly with 950cc or if there was room and a large enough wing a 1200cc tank.

John

Boomerang1

I've got a Bobcat 50 with about 650 sq in & it weighs about 9 pounds + fuel.

It's powered by an earlier silver cased 44 & it flys like a missile at full throttle, most of my flying is done at about 1/2 stick although I don't think that equals 1/2 power as the thrust is not linear to the stick.

Like John suggests it's fitted with Spring Air retracts & wire legs. I don't use brakes on it, not reqd in Oz.
I know the AMA requires brakes on turbines, I think it was Dave (rcguy) that provided details of this simple, light brake. - John.

Avaiojet

John,

That link is valuable information. Thank you for that. That L-39 is perfect to model my scratch C-101 after. Basicly all the same math. Mine may be a bit heavier, but I can cheat on my span and increase it to 50" or 52".

As far as the placement of the engine, just aft or partically on the CG would be warrented. I need to acquire ALL the components related to the engine then facter in normal R/C stuff to determane placement for balance. Fuel included. This is important.

Here's the thing. I need a "spent" Gold 44. That is, one not running. I need this non running engine to fit it into my model now. If I purchase a new one, I'm going through my warrentee needlessly, taking up warrentee running time for the build. I should purchase the engine and have it ready to mount, when the airframe is completed.

Especially with me, takes me forever to finish a model. I'll go through the warrentee time and never run the engine.

Anyone got a non running Gold 44 they can lend?

BTW. Is there a turbine just as small as the Gold 44 that delivers more thrust. Doesn't matter if it costs a bit more. Could kick it up a notch.

Charles

craigdyer

Hi Avaiojet

Why don't you just mock one up out of foam, balsa etc and add lead to get the weight of the MW44. A rough estimate would be all that is needed to get an idea of CG. I don't think there would be too many non running 44's out there.

Hope this helps.

Regards, Craig Dyer