FW P-51 Old Crow

[ridgerunner]

Summary: How to set/adjust correct amount of "toe-in"?

I'm finally getting around to assembling my Freewing 1410mm P-51D "Old Crow". I've checked out all the servos with a servo tester and they all work just fine. I've disassembled and reassembled the landing gear adding loctite to all the metal-on-metal fasteners (especially the set screws). I've read through all the threads, both here and over on RCG, and want to set up the main gear with a small amount of toe-in. The method of adjustment I'm going to use is to (very slightly) bend the ductile main bar (trunion?) at its curved portion.

How does one measure the amount of toe in?

[Jet Fixer]

Summary: How to set/adjust correct amount of "toe-in"?

I'm finally getting around to assembling my Freewing 1410mm P-51D "Old Crow". I've checked out all the servos with a servo tester and they all work just fine. I've disassembled and reassembled the landing gear adding loctite to all the metal-on-metal fasteners (especially the set screws). I've read through all the threads, both here and over on RCG, and want to set up the main gear with a small amount of toe-in. The method of adjustment I'm going to use is to (very slightly) bend the ductile main bar (trunion?) at its curved portion.

How does one measure the amount of toe in?

I just had to eyeball mine. If you look closely straight down the trunion you can see a mold mark on the surface where the attachment screw goes through to connect it to the strut. That will give you a reference to use. Be careful when twisting it though. I broke one last night.

[Jet Fixer]

Fortunately, my gear retraction and extension have always been flawless.
This probkem was really common on the Iron Ass version...but with a few exceptions, seemed to be corrected on Old Crow when they beefed up the retract servo motors. Check the thread on RCG I mentioned in an earlier post...there were quite a bucketload of posts on your gear issue. The only suggestion that comes to my mind is to delay gear retraction, don’t accelerate too much, but reduce power while retracting the gear. That big 2-blade prop blast may be generating far more air resistance to the servo/door combo than your actual airspeed at that moment, if you’re at full power. Something else to check is not to be pulling up into a climb at retraction...the combination of airload and prop thrust together with “G” loading could overstress your retacts. Just a thought. Maybe someone else can offer a fix...
DB

I got two really good flights today. Again, thanks for the assist. Trim is perfect. 0 pitch and 0 roll required for level flight. Still need to work out the flap mix. Yours is way too aggressive for my setup. I'm going to be close to neutral mix I think. Here is a highlight reel from today....

[deadbug]

got two really good flights today. Again, thanks for the assist. Trim is perfect. 0 pitch and 0 roll required for level flight. Still need to work out the flap mix. Yours is way too aggressive for my setup. I'm going to be close to neutral mix I think. Here is a highlight reel from today....

Great job! Nice flying. Now aren’t you glad you didn't get rid of her?
If your flap extensions didn't match mine exactly, my mixes wouldn't have worked for you. IIRC, your flap extensions were less than mine, so there would be less of a need for up elevator mix.
Again—great job...glad I could help.
DB

[markparode@gmail.com]

Almost finished assembling my new Old Crow but after about 6 times one of the main gear is stuck in the retracted position. I can hear the mechanism running when activated but no movement at all with the gear. I cannot access the mechanism because the gear door covers 2 or the screws that hold it in place. Anyone have any suggestions?

[Grossman56]

Try increasing your servo throws, I've had that and it helped. It sounds like its not completing the retract movement. If that doesn't work, pull the wing off and use a servo tester on the retract, that might work, it should, I've tested mine with a servo tester and it retracted and extended.

Grossman56

[Jet Fixer]

Almost finished assembling my new Old Crow but after about 6 times one of the main gear is stuck in the retracted position. I can hear the mechanism running when activated but no movement at all with the gear. I cannot access the mechanism because the gear door covers 2 or the screws that hold it in place. Anyone have any suggestions?

You should be able to get the doors off even if the gear is retracted. I use a small flat blade screwdriver between the door and gear bucket at the hinge point. Insert the blade and give a slight twist while lifting the door up. The linkage will still be attached to the strut, but there should be enough room to op that off once the door is loose. You can do the same with the inner door but it is a little trickier. After that, you may have to open the actuator up and look for internal damage. The servos are metal gears so they probably aren't stripped, but they may have gotten misaligned so the motor won't turn them. That should not have happened unless something in the housing came loose or broke.

[ICM]

Down to the bone yard.

That's how they sat, you can see the minimal damage to the wing a little wrinkling on the picture right side, I can repair that and either reapply the Flite Metal or not, HMMMMMM...

Grossman56

I have similar minor wrinkling on the fuse of one I picked up from a friend. How did you repair yours?

[Grossman56]

I used light weight spackle for deeper wrinkles, for lighter ones I filled them in using Minwax spar Varathane, it takes a few coats. These particular wings are from My Little Gal II, the Hmmm, was the trigger for the rebuild. Recently, I stripped the nose and resanded and filled with the spackle then recovered it with Flite Metal.
The paint I used was pretty thick as well, almost the consistency of whipped Cream Cheese. The first one is made by Delta Creative. It's called Ceramcoat Metallic Silver. The second one is Sargent Art Metallic Acrylic paint silver. Both I found on Amazon and have had good success with them the Sargent being ever so slightly darker than the other, both are thick and water based, so they will fill in some minor wrinkles by themselves. I just finished rebuilding a Bearcat that sat in the junk box for 5 years, did what I could with the spackle, painted it black then a dark blue which came out pretty close.

Grossman56

[ICM]

Thanks Gross. How did you get rid of the ridges on the wrinkles, sand them down?

[Grossman56]

Yep I got a set of the block sander from Wally World and some 220 grit and finer, works great.

Grossman56

[ICM]

Thanks again. I've assembled the necessary materials/paint, ready to tackle the wrinkles and restore my bird to its former pristine appearance.

[Grossman56]

As an example, my old P 40 had some pretty bad gatoring, so I used the Spar Urethane and 220 grit sand paper. Coat, coat sand, coat coat sand. Eight times if I remember right, eventually, the gatoring filled in. I was questioned about the extra weight, but I never noticed any difference in performance.
Stupid me, took her outside for some pics on the back deck and forgot about her so she gatored again. I'll have to go through the process again, but I recoated it with Minwax flat Urethane and she looks good, as in authentic good, the P-40's that the Flying Tigers were flying were pieces of junk that would have been scrapped out in the states.
Anyway, back on topic, you can work most things out with a bit of patience, heck I even redid the Avanti's leading edge doing the same thing.

Grossman56

[Grossman56]

I was just looking at the Mustang page on Motion RC and one fellow in the review section was having trouble with landing gear alignment. I've had that with this plane and the FMS Mustang as well. You pull the pin that joins the landing gear to the retract and you file it to a slightly different angle. I've done this several times, especially when making my own pins. It's a simple fix.

Grossman56

[RAFALR30]

[RAFALR30]

My Crow...but not old :-)

https://youtube.com/watch?v=JIxh18_i9TY&feature=share

[Brant25]

Thinking seriously about getting an Old Crow for this spring (maybe now is better?). Are the retract issues mostly solved? What are the chances this thread will continue for a while?
Thanks for any input,
Brant

[Grossman56]

Nothing has really changed on this airplane in regards to retracts, the same retracts that were on the "Iron Ass' version. It's getting to be an old airframe, still good but definitely not a beginner airplane. Personally, I prefer the FMS P51D. Just sayin'

Grossman56

[Brant25]

Thanks, Grossman. All options considered.

[Brant25]

ESC Timing?? Has anyone increased the timing on the 80 amp Freewing ESC from stock "low" (3.75 deg) to "medium" (15 deg) or even high (26.25 deg). Could this be an acceptable way to improve the performance using the 14x8x4 blade prop?