ocelot31454

I'm building a 1/2A Royal P-51 Mustang. The plans call for a .049-.051 engine. Originally, the plans call for rudder to be fixed and the plane hand launched. I guess that's why the plans show a non R/C engine. I have modified the rudder to be servo controlled. I also would like to change the engine to a servo controlled one. I have a new Cox Tee Dee .049 and wondered the throttle sleeve that I see offered can be put on it. If not, I have a Norvel .074 that is for an R/C plane. The hobby shop where I get most of my supplies doesn't think a .049 will be big enough. The problem is the Norvel just barely fits. I do have an OS LA15 but I'm afraid that would be too much engine.
I was also wondering about converting from the glow engine to electric but I honestly don't know anything about the electrics.
I was wondering if anyone out there might by any chance have a complete set of plans for the Royal 1/2A Mustang. a friend gave me this one when he got arthritis and couldn’t work on it any more. He had already cut the plans apart, therefore I don't think I have the whole plan. The only parts I have are the patterns for the fuselage and wing and ribs.
Thanks

flyinrog

My Feedback: (1)

A throttle sleeve is best if it is already machined to the engine,,if you just buy one it may be too loose to work or too tight to fit...its a gamble... a .15 is way to big for a 1/2a model, if the norvel can be fitted, it'll be the better match, you can always throttle back...Rog

combatpigg

My Feedback: (3)

How big is this plane and how much does it weigh with all your proposed gear?
The first commercial 1/2A kit P51 I built [either Global or House of Balsa] barely got off the ground with a 1/2A engine, but flew quite nicely with a OS.15 and no rudder.

ocelot31454

The Wing span is 35 1/4 and the fuselage is 25 5/8 long and 2 1/2 at the widest point. As for weight I haven't weighed all the servos (4, 1 standard and 3 Micro), the battery and fuel tank. Tank holds 2 1/2 oz I believe. Guessing I'm gonna say between 3-5 lbs when complete including the silkspan and finish.

coriolan

That's way too heavy, the H.O.B. 1/2A planes were about 20<22 oz flying weight with the heavy flight pack of the time on two channels and were just barely flying with a TD .049/.051. Your Norvel .074 would be a perfect match and can be shoe-horned in the mustang. The Royal kits were more scale than the Fred Reese HOB and might end up heavier and much faster flyers. Trottle isn't really an asset on 1/2A, just ad another servo weight! Unless you have a very smooth flying strip ROG would be tricky and so the rudder is not really needed. 1/2A fly best when light and aileron/elevator is enough control to do almost anything once in the air. Having no trottle servo,no rudder servo and no landing gear hanging down will greatly improve the flyability.

Toysareforkids

My Feedback: (4)

I have the Royal 1/2A Zero with a OS ..10 with a DuBro flat muffler and it's full sheeted, with silk and painted, with3 Futaba mini servosand it weighs 2lbs flight ready. It has no wheels, no rudder.You hand launch it, and it flies great. The plane it's self weighs nothing.
I also have the 1/2A Corsair still waiting to be built. I wish I had the Mustang also.
I have pic's, but their on my other pc and I have to set it back up to get them off it.


Pat

MJD

My Feedback: (1)

3-5lb? I don't think so..

The .074 is a logical choice, as it is lightweight and has good power. And throttles. If you must use four channels ditch the standard servo, that's almost an ounce right there, aka 4-5% of the projected dry weight. Use servos along the lines of HS-65's, a lightweight receiver, and what do you have in mind for the Rx battery? 2.5 oz is a big tank - what kind of tank is this, I am not familiar with a 2.5oz size?

If you are going to get much over 24-25oz, start shedding options IMHO.

ocelot31454

I have enough of it assembled to get a rough weight. I was way off before. With OUT fuel, paint and mounting hardwear it weighsin at 2 lbs on the house scales which are pretty accuret. I still haven'theard if anyone might have a complete set of plans,( blue print and directions) so I now guess it will probably weigh in at between 2-2 1/2 lbs. I also still need to find a canopy to fit this model so any help would be great.

MJD

My Feedback: (1)

So that's 2lb with all the radio gear and the TD or Norvel, and no paint?

ocelot31454

Give or take a couple of onces, yes. Is the .074 going to be too big?

ocelot31454

Oh! the fuel tank is 2oz and round. I thought it was a dubro, but all they list is sq. But they do list a 2.5 oz tank.

hllywdb

36" span and 2- 2 1/2 lbs? Sounds much more like a Norvel 15, Magnum 15, or K&B Aero 18 to me. I don't like going over 20oz with a 74 or 09 on that small a wing, the wing loading gets too high. You will need power and speed to keep that in the air. Like MJD said, time to start shedding some options to get the weight down.

combatpigg

My Feedback: (3)

A 2 pound model needs a .15 to be sporty enough to keep me from dozing off at the controls. No less than a .10.
If there isn't room to accomodate a .15, then figure out where a new firewall should go and give the plane a complete nose job.
Hopefully the wing is up to the task.

ocelot31454

Thanks, that answers one question. Now, any recommendations on prop size? As I can't find a four blade I'd settle for three to keep the realism in place. Thanks again.

MJD

My Feedback: (1)

3-blade for a .15 on a 2lb aircraft, 7-4. I think MAS might be the only one available. For a .10 I'd run a two-blade 7-4.

When they are spinning you can't tell how many blades they have.. it is not uncommon for a scale enthusiast to have a display prop then fit a more efficient (in these sizes) two-blader for flight.

You can make a nice display prop from two wood props.