rossmick

Added 45 degree gussets to the throttle servo plate.
Looked at wing hold down and decided to reinforce the attach point.
1: Added ply filler plate behind and above ARF's installed attach point.
2-3; Then added 1/4" stiffener plate to support the hold down, it should not come loose or tear out quite so easily now.



1; View of my installed tubes in wing for servo wiring. Notice, I have left the strings in the wing just in case they may be used in the future.
2; Use of heat shrink tubing to secure the servo extension connections. All servos are now installed in the wing. I used the digital 130 oz. servos for the flaps.



1; Wing attached. I would like to make the air scoop removable, but am not sure it is worth the effort. Slowly the plane is coming together.

rossmick

Sjanc

I will try your approach and see if it helps on the wrinkling situation. Interesting data on props and speed, thanks. DA recommended the 22-12 for the DA 60 as well, so we will see how in works.

chris923

My Feedback: (53)

Doom,

Sorry I don' t have pics of the install. I do have pics of one G62 on an engine test stand. It has the same installation as on the plane. On Other installs I didn't use an isolation mount, I have never had vibration issue with my G62's. They have all been converted by RC Ignitions.

Ross,
I have a picture of one of my Mustang ARF wings. In August, I needed wing quickly and didn't have the time for proper wing fixes. This is a big mistake. On the Mustangs 3rd flight ( no hard landings) the front half of the wing on the right side completely separated from the wing in front of the spar box. If you look at the picture, you will see the shear webs were installed with the grain parallel to the spar not perpendicular. I sent this picture to Hobby Services at Hobbico, and they sent me a new wing without a fuss. That is why all TF P51 ARF wings need to be modified.

fujiman

My Feedback: (133)

this why i went with a foam wing for mine. wish i had just built my 51 from plans or the kit version. these TF arf/arc kits are very poor quality (JUST MY OPINION).

chris923

My Feedback: (53)

Fujiman,

Yes, the wings are poor, however, I have never had a problem with the fuse.

fujiman

My Feedback: (133)

wonder why TF doesn't address build quality of their arfs???????!!!!!!!! they get plenty of money for them!!!!!!!! oh well life goes on. turning mine into Precious Metal look a like reno racer. DLE55RA, down and locked converted Sierra retracts, special glass cowl, elevator re-position kit, flat black/chrome finish, named......''JANIES GUN''. I'll post some pics when finished. thanks guys for all your posted!!!!!!!

sjhanc

My Feedback: (3)

The structural problem with the fuse shows up between 100-200 flts. The aft wing bulkhead is tabbed into the airply fuse side wall reinforcements creating a couple of slots that reduce the longitudinal side strength because there is less than 2 inches of ply (total) connecting the front end to the tail cone. I lost my second D model to this defect. Made a huge crater in the grass runway. Since then I reinforce this area by installing 3/4 inch angle stock (4 pieces) front and rear of the aft bulkhead on both sides. I have since spotted several TF P 51 A/C with a fatigue crack in the turtle deck sheeting above the aft bulk head. I brought it to their attention but I don't know if they made repairs. This applies to B/C and D models ARF and KITS unless they have been glassed.

In a high G turn there is a considerable load at this point in the fuse, it is supporting the full weight of the front end times the g-force and the down force of the elevators on the back end. The extra strength of the balsa laminations is not enough to make up for the failure of the ply side reinforcements.

fujiman

My Feedback: (133)

WOW!!!!!!!!!! maybe we shouldn't go past a .60 glow engine to power this model!!!!!!!!! one defect after another. wish i could sell mine at this point!!!!!!!!

chris923

My Feedback: (53)

Fujiman,

rossmick

Yesterday was a Colonoscopy, so not much got done. I swear I'll never do one again because of the prep you have to do the day before.
Today, did get started on removable air scoop. Rear hold down done and blind nut installed. Will do the front hold down tomorrow - photos then.
Well, Century Jets does not seemed to have shipped the gear as promised, and I am not a happy camper. Numerous unanswered phone calls, I hope I have not made a large mistake.

Sounds like the major fix to most of the structural problems is glassing the model. I will cross my fingers that the wing holds up until then.

fujiman

My Feedback: (133)

i went with sierra gear for my 51 air operated then had them converted to electric. very expensive!!!!!!!! now the electric gears are available. oh well, this thing has become a deep money pit but can't stop now!!!!!!!

sjhanc

My Feedback: (3)

Deleted. Sorry, it somehow got posted twice, see the next post.

sjhanc

My Feedback: (3)

I hope you guys don't get the wrong idea from my advice on the structural repairs on the TF P 51. In spite of the defects which caused the loss of 2 of my planes and the loss of two more that I deem as preventable ( my fault). I have more than 750 successful flights on this model, and I have video of almost all of these flights thanks to a friend who enjoys aiming a heavy camera at P 51 aircraft. I only pass along this advice hoping that others can use it to improve their own chances.

In almost 50 years of flying RC aircraft none have given me more pleasure and more positive feedback from spectators and other flyers than P 51's. Every time I manage to grease a landing people stop by my pit area to remark on how much they enjoyed watching that landing. In the 70's I had approximately 35 flights out of two .60 size TF mustangs before I went on to jets and that experience, which I never forgot brought me back to the current GS kit and ARF versions that TF has made available.

I don't think you will ever find another aircraft both RC and full size that has as large a fan base as the P 51.
In response to chris923, I also don't pull high g's with my models, I even have the control deflections dialed back a bit and I use a lot of exponential to soften the inputs. The plane that had the wing joiner failure had 202 flights on it and I was executing a slow roll in formation with a Skyraider when the right wing panel just fell off (Top Flite has fixed this problem). I was able to control the plane in knife-edge just enough to hard land almost level minimizing damage to the rest of it and was able to salvage a lot of parts to use in later models. The engine was not damaged. The plane that had the fuse failure had 317 flights when during speed trials using radar as the radar operator called out 122 mph the plane (in level flight) began to nose down. The fuse took on a banana shape and the vertical dive it executed from 40 feet completely destroyed it. None of the pieces excavated from the crater were salvageable. The Fox 2.4 is still in the junk box as not economically repairable. The spinner was molded around the crankcase.

In spite of the structural deficiencies (that can be corrected), the TF P 51 is a joy to fly and at 21 lbs. is very easy to land. At the heavier gross weight that I fly at now (29 lbs.) I use 53 degrees of flap deflection which requires a constant 40% throttle all the way to touchdown but is easily controllable and touch down speed is only slightly higher than at 21 lbs.

The power plant I am using now is the Rimfire 50cc brushless motor, Castle 120hv esc, 12s 5300mah battery, and Graupner 22-12 prop which produces a nice prop rip at 8400rpm.
Other props, such as the Xoar 22-14E, and APC 22-12EW, will go faster and have better rate of climb but no prop rip so spectators are not impressed. Use of the Axi 5345 series or Hacker 80mm motors with these prop could get the plane up to the 120-130mph range (but you better reinforce the plane (glass)) and would spin the props up high enough to get an excellent prop rip but at considerable expense and you would need Thunder Power batteries.

The power systems I am playing with now are in anticipation of the new Hanger Nine 60cc P 51 about to be released which has a larger wing and better airfoil so will be able to carry the 12s 2p batteries that are necessary for at least 10 minute duration with enough left for 2 landing approaches. Right now I have 5 minutes and 2 landing approaches. I have a more powerful brushless motor that can swing APC 26-15E props or 24-14 4 blades. Development of the current TF p 51 has maxed out because the symmetrical airfoil absorbs too much power and can't glide along at reduced power at high gross weight.

fujiman

My Feedback: (133)

looking back in this thread and remembering all the mods to the wing scared the heck out of me so i ordered a foam wing and i'm building the center section as if it were one piece with the outer panels added to the center section. also beefed up with cordon fiber strips and fiber glassed. the fuse will have all the issues dealt with also, firewall, wing saddle, weak tail attachment, etc. hopefully all weak links will be covered, except just piling it into the ground!!!!!!!! a lot of extra work and expense for it being an arc kit.

Shaun Evans

Fuji,

Who makes a foam wing for the TF Mustang?

DLEVETT

My Feedback: (13)

Hi Fujiman,

Where did you order the wing from?
I am essentially done building my P-51 but would like to try that 3 piece wing that you mentioned.

thx
Dave

DLEVETT

My Feedback: (13)

lol, you beat me to asking the question.

sjhanc

My Feedback: (3)

Dynamic Balsa
dbalsa.com

sjhanc

My Feedback: (3)

On the wing I cut into the bottom sheeting 1/4 inch away from spars, ribs and leading and trailing edges. I save the sheeting I cut out and then install a 1/8 inch aircraft grade ply piece on both sides of the landing gear mounts stretching from the leading edge all the way back to about 4-5 inches behind the wing spars. The ply you install only needs to fill the space vertically between the spars and cover the lightning holes in the ribs. It needs to cover the landing gear hardwood pieces. These hard wood pieces are factory glued (if there is glue) with something that has the strength of paper glue. You can pry and wiggle the hardwood and remove them easily. Clean all the glue residue from the ribs and hardwood. reinstall them with whatever adhesive you like. Unless you use paper or rubber glue I don't think you can find glues on the hobby market as weak as the factory glue. I use brown Gorilla wood glue. While you are in there apply super glue every where you can reach in every access hole in the wing. My first arf had no glue from the inside LG. MNT. out to the wing tip of the right wing panel. I think somebody went to lunch when it was time to glue this panel. I have made mods. that were much more extensive than this but I think the procedure I have outlined is more than adequate and lighter. It is what I am currently using. You still have to land gently, a good bounce will damage a 20 lb. + airplane no matter how much you beef it. When finished install 1/2 inch wide balsa strips under the wing sheeting where you cut out the original sheet (follow the original grain) clean up the ledge you have created, install the original sheet pieces you cut out, they will fit perfectly. A little sanding and recover the areas you worked on and it is ready to fly.

chris923

My Feedback: (53)

This is more or less the way I fix my Mustang wings .

chris923

My Feedback: (53)

You will have a difficult time trying to do a three piece as in a Byrons. The gear placement, opposite the ailerons is different, it will require a fair amount or re-engineering. You you know someone who has done it with a TF Mustang, I would love to know how they did it! I sure it's possible, you would be better off modifying a Byron 3 piece wing to Fit. The wing span is almost identical.

ForcesR

sjhanc; I didn't know such a site existed; thank-you very, very much for sharing the link!!!

Roger

Shaun Evans

Sjhanc

Could I trouble you to post some pics of your foam wing? I would very definitely go with building a foam wing for the Mustang when I do one. That's great news that they have these. BTW, what kind of adhesive did you use (or do you plan to use) to sheet the cores?

rossmick

1: Modified air scoop. Front hold down plate epoxied in and attached with screws for extra security. Rear plate mounts on top of rear former hold down arm.
2-3; Rear hold down arm cut in to rear wing former and glued in place while bolted to air scoop held in place with tape and weight. I will Aero Poxy around the arm to help secure it.
4-5; Front hold down arms epoxied in. Right now the arms are just screwed in place, but will be epoxied and screwed now that I know they are in the correct position. I thought I would have to sand or shim to hit the correct height, but it came out right on the button. I will use a nylon bolt to hold scoop down and in position.
6: Air scoop in position and held down tightly.



1; Cut additional openings in standoff for access to the swivel for the throttle. Note, that now that all is in position I change out the standard nut for a Nylock nut on the swivel, This applies to all swivels.
2; Throttle servo mounted and attached.
3; Engine mounted with blue thread locker applied to stainless bolts.

sjhanc

My Feedback: (3)

Sorry, I have it but have not started building it yet. It includes the sheeting and necessary wood blocks. I have the ply gear mounts but I think I made them out of wood I already had on hand. I also made air ply root ribs. I looked at the kit and I don't see any spar wood which I will install anyway. I will also install a rib next to the landing gear mounts and shear webs between the mounts and the root rib. Last thing will be an air ply leading edge spar with lightning holes in it behind the balsa leading edge connecting the front of the gear mounts. I did this on my B model kit wing and it made the landing gear area of the wing exceptionally strong. this was done because the engine in that plane was the ZDZ 80 and the gross wt. was 29 lbs. I didn't want the kind of problems I had with the fragile TF wing. I also engineered a partial Fowler flap installation on that plane which produced impressive low speed handling. It could be slowed almost to walking speed and when it stalled would lower it's nose and continue flying. I will post pictures of the jig I built to set the location of the hinges in case any one else wants to try this. as a matter of fact, this design was copied from pictures of a man carrying Mustang that I saw in a magazine. Further research prove that this hinging is closer to the real mustang than the more common center hinging on most of the popular RC designs. Too bad North American didn't take advantage of the benefits of Fowler flaps as did Republic did with the P 47. If you have access to a set of Ziroli P 51 plans look at the flap design- you will see this. All you have to do is watch any RC P 47 landing and you can see the advantage.