JP8650

My Feedback: (-1)

Hey George, I just wanted to take a second and congratulate you on a Job well done so far!!!! It is nice to see someone that takes pride in their work and doesnt hog out their cowling and plane to make something fit!!! I have built many of these 51s and each time I build one (for myself or someone else) I learn something new each time and enjoy building these kits! So Job Well Done my friend!

gmohr

Thanks for the kind words! I've suprised myself a bit on this build hahah. It's a very good kit, but requires quite a bit more woodworking skills than any of my past builds. I've certainly learned a lot on this one...

Regards,
G

JP8650

My Feedback: (-1)

Your most welcome! any thoughts on how you want to cover her?

OSUAV8R

Hi Everyone, I am new to the forum, and have a questin. I have read up to page 30 so the answer may be inthe next 50 pages.. I am just to tired to read it tonight LOL

I am wondering what everyone uses servo wise in their Mustang. and is the prefered method one servo per aileron?

I have the tail feathers done and my CJM retracts coming tomorrow


Thanks

Nate

JP8650

My Feedback: (-1)

To answer your question, I use hitec 5985 on Elev. and or 5955 and either hitec 5645 or 5985 on the ailerons. The reason I use these servos is because I fly a YS 1.20 to YS 1.60 for power. Now you can use a lesser of a servo if you are flying s 2 stroke or a smaller 4 stroke.

OSUAV8R

Iwill be using an OS 120 FS

Thanks

gmohr

I'm probably covering it with Monokote, with some Ultracote for certain trim sections. I'm both looking forward to it, and scared to death of it, lol. The amount of compound curves will make this a real challenge.

On the servo front, I'm using...

Aileron - Hitec HS125 MG Thin
Flap - Hitec HS225 MG
Elevator/Rudder - Spektrum DS821
Throttle - Hitec HS65

Regards,
George

JP8650

My Feedback: (-1)

I think you will find it will be fairly easy to cover. Though I will say you will front of it in a few pieces! as well as the chin and depending on how you cover it you can get the wing fillets in one piece. And covering those and the top of the cowling will be your most timely parts of it......It takes me about 80+ hours to cover a T/F P-51. And im sure most of that is because i have a bad habit about making sure everything is perfect...lol

gmohr

Hi again!

I've got the wing setup, servo's installed, and control surfaces working. Here's a few pics of the installation. I've surface mounted the servos to 3/32nd ply hatches, which are themselves flush mounted to the level of the wing skins. Makes for a neat and tidey install, and very low slop. Those thin Hitec aileron servos are really nice units.

Regards,
George

OSUAV8R

Will a standard size servo not fit? Why use the thin servos? I assume they cost more then a sandard size one

JP8650

My Feedback: (-1)

yes they should! I have standard size servos all around in mine....maybe hes cutting down on weight ?

Riddle4U

George, really nice quality on the construction. I went with belcranks for the ailerons, probably not as slop free a method for sure. I'll use one high torque/high speed expensive servo in the middle. I hope it'll be Ok? My tip mass will be lower...yeaaa..that's it?! I guess it worked fine for the contest winning prototype. I'm keeping the links and servo arms buried in the wing on mine. Your set-up is what the bigger acro types use, so maybe better your way. I dunno.

CRJDriver

My Feedback: (57)

Guys, I have built the 1/7th TF Mustang and have been flying it continuously since 1992. Itis powered by a OS 61 SF engine and -Tec Pitts muffler. I went with the stock aileron setup driven by just a standard FUTABA S 148 (BB conv) servo and has worked flawlessly over 17 years of faithful regular service. This airplane is fast with this setup and flies like a pattern ship. IMHO, you really don't need to go overboard with expensive hi-torque/digital servos in this model unless of course you prefer to OVER power this airplane by a large margin. Remember, it is a fairly light machine when assembled per the plan. That said, I do plan on replacing the aileron servo soon because I beleive that 17 years has probably exceeded the useful life of the brushes/gear train. You're gonna love this airplane! It's a real sweetheart! Nice job on the builds guys!! Here is a picture of mine done up like the box.

Regards,

Chris

Riddle4U

Thanks Chris. Yours is nicely finished, I plan on the stock scheme for my first one also. I always thought this one could come out pretty light as you say. I am sure your confidance-building comments will inspire us all. It sounds like your saying my stock belcrank/aileron set up will work just fine? Is the central ball link set-up on the central servo secure enough (i.e. won't pop off)? i'd like to see some more pics! Particularly from the belly side. I am psyched to finish her up now!

CRJDriver

My Feedback: (57)

Yes, the stock ball link setup works perfectly. In fact, I just removed my original aileron servo (17 years old) and replaced it with a Hi-Tec HB-635. The original servo still performs as advertised and I had a spare Hi-Tec on the shelf. It took quite a bit of force to get that ball link to release from the ball which was very surprising after all these years. I will snap some shots of the belly and upload them for you.

Chris

skyriter

Nice looking plane. I have seen posts that indicate that the position of the CG on the plans may not be where it should be. Where did you locate yours? Must be correct, as your plane looks as good as new after 17 years of flying. Also did you do any extra work on the landing gear?

Bruce

OSUAV8R

can some of you wak me through how you got your retracts to sit a bit lower onto the wing?  I have CJM retracts (1/2" strut) and 4" wheels,  I would love to get the entire wheel in the well, but if its not possible... I'll live, but i would at least like to have upper gear doors.

I have trimmed the rib a bit to lower the rail, but I dont want to do any more till I am sure I am not making a mistake..  How to you keep the two gear even? besides measuring both sides?

pics to follow

Riddle4U

OSUAV8R, it would take too much to completely describe every task in fitting a scale gear here with scale gear doors (if even one knew about CJM). I think I decoded your statement correctly (or not)? I spent weeks staring at the plans measuring..remeasuring, and comparing to the real thing..then back to the model. Each of us here has kinda found a solution in the end. If you ask one specific question, though, maybe one of us could help? For instance, I have a communication gap when you say "upper" gear doors. That means nothing to me. There are inner doors; and there are the doors attached to the main struts. Let's define terms first, then I or someone could advise. You need to do some more of your own work first, me thinks. Please devise your proper question. Getting a proper scale retract to work is one of the more difficult tasks in this nice hobby. One would have to personally look at your project to be of help as far as the way you framed the question, you understand. There are so many angles! Stare at it for many hours, and then if you can figure out what you want to know, I guarantee someone here can help you! This thread is NOT a magic wand.

CRJDriver

My Feedback: (57)

Skyriter, If I remember correctly - I balanced her according to the plans and this has served me extremely well for almost two decades. For what its worth, I have never built a Top Flite Gold Edition kit that didn't fly perfectly with a CG setup per the plan. There are no bad habits at all with this machine. Attached are pictures of the underside of my Mustang. These show the position of my Robart 605HD retracts with Robostruts fully retracted. This was the best that I could do at the time and has proved well. I beleive that getting these gear to nest so that the doors are flush was more of a challenge than I was up to when I built this. My GS P-51 however, I was able to get those perfectly flush with the underside of the wing but that is a different thrad for a different day. I have never work with CJ gear OSU so I am at a loss here. Maybe you can upload some pictures of what you have going on now and we might be able to offer you more assistance. Good Luck Guys!

Chris

Riddle4U

Thanks Chris! Just what doc ordered. We all want to help here, so not being belligerent OSU... Just check it out and be more specific, is all. We all want to help!

I don't mean to start any controversy, but CG has a range. Think about how heavy the full fuel tank is, and how much weight is burned off. Sport planes I have built, as well as my full scale knowledge indicates that for normal subsonic airfoils...about 30% MAC (mean aerodynamic chord), is generally pretty sufficient. Be conservative and call this maybe 27% with the tank dry. Then when you burn off fuel you are assured that the CG doesn't end up behind that. Most aircraft are pretty safe at this 25 to 30% behind the mean (average chord). This is simple when you don't have a swept wing. The Mustang is fairly normal here. Don't let the funny bend in the Mustang's leading edge throw you too much. Just don't go too far aft and you're stable (if a bit inefficient). If you follow the leading edge from tip to fuselage, and ignore the bend in the wing...go back behind the leading edge 27% for a start..maybe even to 30% (no fuel). The plane will fly! When you find it lethargic on climb (good airspeed), you'll know you can move it back a quarter inch, at least. Fact is; If CG couldn't range a bit...many more planes would crash. So yea, remember how much weight you lose in fuel! balance it dry about where I said and..oooh la la! Don't sue me Craig!

Edit: I just pulled the plan. The CG is at 4.88 inches behind the point where the wing meets the fuse in front. This is 31%! Pretty much to the rule! No worries! Don't go too much behind and yer happy! Yes Bruce...the CG on the plan is FINE! You could move it back if you're wanting more excitement (don't do it)!

OSUAV8R

Riddle, no worries, I was exhausted when I posted the last post. all I want to do is get the retracts to sit deep enough in the wing to allow me to use OUTER gear doors, I have no intention of putting on inner doors. I want to maintain the geopetry of the gear so that landings do not get difficult, i.e. tipping over. I will upload pics of what I have so far ASAP

Thanks

Riddle4U

Go by the plan profile for forward rake. Same as real one. Don't "tip over".

OSUAV8R

I plan on that, the trick is... getting the rails low enough to get the wheels to sit in the wing but not pop out the top... I was going to try lowering the rails more in the rib closer to the center, that should also help keep the legs vertical as opposed to splaying out... there is just very little room... I am not going to go nuts... I know it wont be even close to scale, but anything I can do to make it a little bit better would be nice..

that said... I really just want the gear to function properly  lol

Riddle4U

Seriously..it ain't that big an issue (gosh I hope). Just get out your X-Acto blade that works, or a Dremel...whatever. Take very small amounts of material at a time. Place the gear in. If it works almost..take off some more..repeat..almost..repeat..check it..remove some more. Believe me you'll get it accomplished. Surprise yourself!

This is the pride of building, and have fun!! You're building a model airplane...not bookshelves! Yes.. FUN! Slow down and feel the wood dust in your nostrils..good for the soul.

OSUAV8R

Riddle, I know it should be that easy, but after reading most of the thread, it seemed like it was very difficult.  and I wanted to make sure I wasn't doing something stupid.  it sounded like people were grinding down the rails, not the ribs. adn keeping both gear even is a major concern.  I love building and am very proud to say that I have NEVER flown an ARF

I just wanted to get some pearls of wisdom... thats all