Mustang Fever

My Feedback: (2)

Thanks, Beagle.

In the words of Bill Murray in Stripes, "There must be something wrong with us. There's something seriously wrong with us!"

Mustang Fever

My Feedback: (2)

After I got the outer door fiberglassed and fitted into the opening, I was able to use tracing paper to trace the outline of the opening around the retracts and the end of the door. The kind of "horseshoe" shaped filler piece is the result. It's 1/16 balsa, as is the outer door, and will get glassed after it has dried. I plan to glue the hinge to both the door and the filler afterwards. I used Elmer's nano glue to glue the inner door hinge to the door, and it works really well.

Riddle4U

Scott, with all due respect. Light pushrod systems are prefferable in my opinion (and just my opinion). The small weight of a servo is multiplied by the arm (and long), of the tail moment. A few ounces in the tail is HUGE. I know the pushrods are not weightless, and pull-pull are even lighter; to build an overall lighter plane I would suggest against it (tail servo). If your engine is so heavy (my 1.20 O.S. might be) that you require tail-weight (almost never the case), than OK. This 3D inspired movement to have an enormous amount of servos, with supposedly reduced slop e.t.c. has run it's course. Hold all of your combined servos in one hand, and you will immiediately see that it is time to use our quality high-speed/high-torque servos to account for themselves. That is to say run PUSHRODS! 100Oz/in. servos can run centrally (importantly at the center of gravity). We are getting lazy, and the radio manufacturers just love selling expensive servos. Best regards, and hope your plane comes out terrific! ..again just my opinion. Oh..and I appreciate your idea of not having pushrod exits (I do like your thinking), but we already have four servos hanging in the wing with big hatches, servo arms, and somewhat long pushrods at exit(well, I did stick with TF's one aileron servo, but two flap servos). I actually think TF did a great job with this P-51 design. One thing I want to do, and which would differentiate from the nice ARF they have now, is to add the faired-in section at the rear of the canopy where it meets the fuselage top. I'm going to cut a piece of soft balsa following the top-view of the rear canopy (more or less a narrow horse shoe), hold some sand paper over the top of that part of the fuselage, and sand-down the part till it conforms with the fuselage cross section. Than radius that additional balsa so as to make the nice smooth transition from rear canopy to fuselage. Sorry about my dissertation above..Ha ha! Anything we can do to get a quizzical inquiry from that ARF flier the better!!!

Riddle4U

Bob, I'll second the emotion on "Landing gear support system". Very funny. It was second to my exhaust manifold in halting my progress, ha ha. Your gear doors look quite scale, and I'm glad people take the time for these once in awhile(like me). When you finally are at the field, you may get this question: "WHAT! That's a Top Flite?, MY ARF didn't come with a gear and doors like that. Is yours a newer version?" Ha ha ha ha....

saramos

Hi Riddle,

Weight is one of the potential deal breakers on my idea. I'm not doing this to get max torque or 3d performance, but rather to have all linkages hidden and achieve a more scale result. I will be using a rotary drive setup on the ailerons, and changing the flaps to work from torque rods with the servos in the fuse section of the wing. The two potential problems with using the rotary drive for the rudder are weight, and potential flexing of the drive setup. I would really like to have none of the linkages, rods, horns visible anywhere on the plane, but may need to compromise with the rudder.

Scott

Riddle4U

That sounds good Scott. I would be happy just to get the aileron external aparatus to be close to scale; there must be some horn and linkage on the real one. The problem always becomes flutter with short (scale) control horns, e.t.c. As I mentioned I'm just using one good servo (high speed/torque) for ailerons, and I wish I had thought of modifying flaps to a torque rod arrangement as you mention (I'd use one good servo). The idea or goal for me is to keep the total weight down, as always, while maintaining or improving the scale appearance. Is there a pic of your "rotary" arrangement on the ailerons? Just curious. -Eric

tony-howard

My Feedback: (224)

The aileron linkage on the full scale Mustang is completely internal. And both very unusual - at least for us modelers - and very hard to describe.

saramos

Here's a picture of the RDS setup.

You can find more info at:
http://www.irfmachineworks.com/rds/

Scott

Riddle4U

Thank you Scott. That is the same linkage design shown in the Brian Taylor 82" Corsair plans. I think there might be a pick on "Going for it, 82" Corsair build"- which is RWright or something. He is doing a nice job on his Corsair (wants to do folding wings...aahem). Are you using that funky servo or just the linkage? I'll have to dig through this thread a bit more, but holy cow it is big! Sounds like you got a good handle on matters.

saramos

I'll be using the Hitec HS-125MG slim wing servos. They measure 1.18" x .39" x 1.33" and shoud fit nicely in the wing. They weigh .84 oz and at 6V have 48.6 oz.in torque.
I have a build thread going here too: http://www.rcuniverse.com/forum/m_47...tm.htm#4787216


Scott

Mustang Fever

My Feedback: (2)

Well, guys, I bailed out. I've had enough of this landing gear door business to last forever, so all of that stuff went in the trash bin today. I'm filling in around the struts and tires with 1/16th sheet.

I just wasn't that pleased with the job I was doing, and it all struck me as having a high unreliability potential. I want this airplane to not only look nice, but to fly good and be reliable.

More pics later.

Riddle4U

Sounds like you were on the right track. I guess I don't understand, are you bailing on gear doors entirely?[sm=cry_smile.gif]

Mustang Fever

My Feedback: (2)

I think so, Riddle. I think the skills required to make them work correctly and be reliable are beyond me. I could only use one hinge per door, due to the shape, and I don't think the setup is going to be strong enough. I have nightmares about a door coming loose in flight and jamming up one side of the system.

saramos

I'm sorry to hear that you're giving up on them. I suppose that doesn't mean that you can't re-visit installing gear doors in the future. But I can certainly understand the desire to move on.

Scott

Riddle4U

Mustang fever, I'm going to get my TF "51" going again in the next couple weeks. I was planning on laying up fiberglass over a monokoted section of the wing before I make cut-outs. The inner doors definitely need two hinges. I think one needs to use the offset (dogleg lookin thinga ma jigger) style hinges, due to the airfoil curve in the middle. I'll take pics when I get there. Who knows, maybe I'll be cursing too!

Mustang Fever

My Feedback: (2)

Thanks for all the support, guys. I decided to put the Mustang up on the shelf for awhile. I guess I'm not ready to give up on the gear doors, but neither am I ready to keep working on them. I bought a Hangar 9 Sopwith Camel to put my .91 in, so now I can take my time with the 51.

Later.

I B BUCK

Hey Bob sometimes it's better to take a break from something. You'll be working on something else and all of a sudden an idea pops back in.
That Sopwith is pretty too. I shelved my stang and somehow I keep getting something new to play with. Iwasn't going to buy anything new
until I finished the mustang. Ended up with a free H-9 P-47 didn't even have to pay for the engine. The BCMA 26 cc gaser fits nice .

I know this is the TF 51 build site but had to share these.

Mustang Fever

My Feedback: (2)

Hangar 9 ARFs are really nice, aren't they? Very well engineered and lots of nice little touches- every fastener on my Sopwith that has to be R&R'd during setup was blind nutted.

bull51

Ticketec,

First of all, sorry to hear about and see your crash. But, repairs have her looking good as new. You have done a phenominal job. I hope to have a fraction of you ability someday.


Everyone is doing a fine job, in my opinion. I have to give thanks again to all of those who posted here and helped me though his kit.

I am getting started again and have some difficutly with the wing saddle. I've got the saddle on and the strip of balsa glued in, but the balsa filler, oh my gosh, what a pain in the neck. i can't get it to stay put. Is there a trick to this stuff? It would rather stick to my fingers thatn the balsa. And, when i get it on, its a lumpy mess. Any suggestions. Ill get pics of my progress loaded soon. Thanks.


*******EDIT: wing fillet is the part I'm having difficutly with, not the saddle. ******
Fillet is on and glued, strip of balsa on and glued.
Cant get the filler to stay where i want it. Any trick or techniques for using the filler?

Mustang Fever

My Feedback: (2)

Bull-

Is it the wing fillets that are giving you trouble?

bull51

Mustang,

Sorry, was very tired when I posted, yes it is the wing fillet. Fillet is on and secured, strip of balsa secured, but cant seem to get the balsa filler to cooperate. It just does not stick when I try to smooth it out. Sticks to my fingers instead of the fillet. Thanks

bull51

Here are those pics I mentioned

bigtim

My Feedback: (13)

this is a product I use and it works very well, Minwax wood filler,it builds up fast and sands nice and smooth,I add just a small amount of water to the can,and stir it well, to make it a little more creamy.
I then do moderatly thin coats to build up the surface,letting each layer dry between coats it drys fast, when I get to the final finish layers, I apply it with my finger and then dip it in some water to do the final smoothing let it dry fully then sand,if you add to much at once it will crack a bit but fills with the next coat, its made for wood and sticks really well to the surface.
heres my Top Flight P-47 before and after glassing and paint when the filler is sealed its hard as a rock.

bull51

Bigtim,

Thanks for the input. I have the Elmer's version, but have not tried it yet. I was concerned about the weight and the ability to sand it smooth. I guess I could try the minwax wood filler and see what happens. I just dont have the patients for the balsa filler. It take too much effort to get it to stay put, then, after all that, its a lumpy mess.

Mustang Fever

My Feedback: (2)

Bull:

The only other time I ever did wing fillets was on a Great Planes 40 size P-51. I used 45 minute epoxy mixed with micro balloons. (heavy on the micro balloons) It worked very well, but boy was it dusty when sanding it.

BTW. Started working on mine again today. Put a paper tube in each wing outboard of the flap servo bays, to allow threading the aileron servo extensions through the wing after it's sheeted, etc. I went back and forth on what to use for the ailerons, and finally settled on a pair of those HiTec thin, MG wing servos. Kinda pricey, but they fit real good and have plenty of oomph.