RC Foam plane repair thread!!!!

[Younggun]

Making this thread in an attempt to show how easy and cheap these planes can be to repair. Will do my best to document the process as best I can, maybe it will help someone else here if they decide to start playing with these things.

NOTE: You should always remove the battery as soon as you recover the plane. If a LiPo battery is damaged in the crash it could short and catch fire.

First things first. Gotta go over the whole plane and make sure we find all the damage.

I'd already done a visual inspection of the plane. Noted any damage on the wings, control surfaces, and fuselage. Some matters, some is cosmetic. In that inspection I found:

Tail section of fuselage broken just in front of horizontal stabilizer- Must be repaired

Moderate scuffing on left wing leading edge- Could probably fly with little effect on handling.

Lots of cracks on the cowl-Must be repaired or removed.

Steer wheel loose, turns freely- could hand launch, could probably remove all gear and belly land the plane, better to fix though.

Light bend at very tip of prop, no stress mark- generally, you would never attempt to repair a prop, especially if there is a white stress mark. In this case it is such a small area and no stress mark it might be fixable. Would probably only cause very light vibration, if any if not repaired. NEVER attempt any repairs on a wood prop.

Broken servo arm on right Aileron-must be repaired.

The important thing is to carefully look over the entire plane and make a note of any damage you see. Last thing you want is to get it out back together just to crash again because you didn't notice a crack in the wing.

 

[Younggun]

Ok, so we've checked over the plane, packed it up, and got it back to the house. Time to check more stuff.

The battery should already be removed. If it was not damaged it should be recharged and ready to go. But NOT in the plane.


This will apply to the apprentice, but much will cross over.


First thing to do is remove the prop. For 2 reasons: 1. I need to remove the prop so I can take the cowl of and check the firewall and engine mount. 2. Because we will be plugging the battery back in and don't want to lose any fingers.

So, prop removed, cowl removed. Check over the motor mount and firewall. Make sure everything is tight, no crack, no stress marks.

Check the propeller shaft. Make sure it's tight, no wobble when it's turned. The motor should spin freely. Make sure there is no dirt in the housing. These motors are pretty tough and usually the mount or prop will give before the motor is damaged.

Next check the ESC, receiver, and servos to make sure they are still securely mounted and there is no obvious damage. Look over the push rods that run through the fuselage and check for bends of breaks. Check the horns connected to the servos.

If it looks good, it's time to install the battery and power the plane on. Actuate all the servos one at a time. Listen for any grinding or binding sounds. If it sounds good, put a little resistance on the push rods and make sure they still sound good. Run the motor up a little (prop still removed) and listen for any strange noise of vibration.

Make a note of anything that is found and remove the battery again.

Make sure you check EVERYTHING. Just like before, you don't want to crash your newly repaired plane because you brushed over your post crash inspection.


I found that the nose/steer wheel was turning freely because the horn had been pulled lose from the servo. Easy fix.

Everything else is working fine.


Next, the repairs begin.

 

[F350-6]

This thread would be better with pictures.

 

[Younggun]

They are coming with the repairs. Guess I could do some showing the parts that are checked.

 

[Younggun]

I didn't check my engine mount very well earlier.

 

[Younggun]

Pics not working tonight for some reason.

 

[Younggun]

Ok, so I somehow missed this earlier.

This shows exactly what you should be looking for when checking plastic parts. That is the lower side of the engine mount. I didn't see it standing over it checking the engine. I went ahead and pulled the mount loose to check it from all angles.

Putting pressure on it from different directions I'd say it isn't weakened to the point that it will break in my next flight, but it definitely needs to have a replacement on standby and watched closely.

I also noticed that the firewall was pulled loose at the top.

No pressure

With pressure on the motor

This can be fixed with a little foam safe CA. (Foam safe superglue)

 

[Younggun]

Ran to Walmart this morning and picked up some strapping tape. Rounded up some toothpics, carbon fiber rods would be ideal but I don't feel like waiting and they might be considered overkill for this model plane.

I inserted 4 toothpicks in one side of the break, making sure to get them as straight as possible. I went on at a time, putting the to sides together making a hole in the opposite side for them to hit and checking alignment before going to the next.

Once everything was going together and aligning properly, I removed the toothpicks and applied foam safe CA to one half and inserted it back in to the broken tail section to glue them in place.

I measured out 3 pieces of strapping tape and hung from the edge of the table for later use.

Then applied CA to the protruding portion of the toothpicks and the foam where the to halves will meet. Put them together and make sure everything is lined up before it dries. Not much time.

Apply the strapping tape across the break where possible for additional strength.

Let everything dry and apply some stress to the area to make sure it is strong. In this case, the fuselage is flexing ahead of the break.

The whole idea is to create a repair that is stronger then the original. I think that has been accomplished.

While I had the CA out, I went ahead and glued the firewall back in place. It was originally done with silicone which would allow for easier removal later, I'm not really concerned with that and will cross that bridge later if I need to.

 

[orbitup]

Well on your way to getting your A&P license.

 

[Dawico]

Looks better than some of the repairs on my military truck.

 

[Younggun]

 

[ScorpionHunter]

I doubt the fixes would have affected it much, but you might also want to check the balance before you fly it just to be on the safe side.

 

[Younggun]

I doubt the fixes would have affected it much, but you might also want to check the balance before you fly it just to be on the safe side.

Yeah, I'm gonna give it a good goin over before it goes in the air. I've got the balance point marked on the underside of the wings for convenience.

Gonna pick up a small piece of balsa to put at the front of the battery compartment, I noticed a dent where the battery has been hitting it and the foam isn't real thick there. Will probably compensate for any weight I've added at the back in toothpicks and tape.

 

[Shotgun Jeremy]

Man, I'm gonna have to drop off my R/C quadcopter with you. It's a limited edition so I wanna get the foam fixed and keep it as a display piece.

 

[Younggun]

Man, I'm gonna have to drop off my R/C quadcopter with you. It's a limited edition so I wanna get the foam fixed and keep it as a display piece.

Display it flying around in the air as it was meant to be!

Limited edition in what way? Didn't know they did that for quadrocopters.

 

[Shotgun Jeremy]

It came in a special edition Call of Duty Black Ops package. Pretty fun to fly, but after I cracked the foam blade protector in one corner, I put it away for display only. I'm scared to do any more damage to it. Lol

 

[orbitup]

Very tactical

 

[Younggun]

It came in a special edition Call of Duty Black Ops package. Pretty fun to fly, but after I cracked the foam blade protector in one corner, I put it away for display only. I'm scared to do any more damage to it. Lol

That would be an easy fix.

 

[Younggun]

Made a servo arm out of a plastic coat hanger today. Worked in ground testing but using it for flight would be incredible risky and slightly stupid. I won't try it unless I can't pick up a new one tomorrow and the weather is nice.

 

[Shotgun Jeremy]

Yea, there may just be too much wind resistance while flying for the tensile strength of the bar.

Then again, I've never played with airplanes. Just the off road racing trucks and buggies.