Repairing blown body tube

[Scott_Rip]

I've been repairing some of my old Estes rockets lately. One that I need to take care of is my Mean Machine, which was damaged by a faulty Estes motor which blew a hole out the side. So, I'm replacing the engine mount and a fin. The body tube is damage, too. I has a hole blown through it, but the material is still all there. Has anybody ever had success with repairing body tubes like this? I just need to close the hole and still be able to insert a new motor mount.

 

[DaveCombs]

With the Mean Machine being as long as it is, I'd consider cutting off the entire fin can, putting on new fins and putting a new motor mount into the undamaged part of the body tube.

Alternately, if you wanted to preserve the original length, you could remove the entire damaged fin can, build an entirely new lower section (fin can and MMT) and use a coupler to join it to the remaining good body tube.

 

[Scott_Rip]

I've considered rebuilding the section, but I don't want to lose the decals, if possible. One idea I had is to just use a piece of printer paper as backing to close the hole down from the inside. Sanding that down and sanding down the centering rings should get the motor mount to still fit.

 

[DaveCombs]

Have you checked with either Excelsior or Tango Papa for repro decals? (I would, but their sites are blocked at my workplace.)

 

[Scott_Rip]

Hmmm...

Tango Papa has it for $12. Maybe I should just chop my tube a little short and repaint the whole thing purple.

Then again, for the sake of somebody having the experience, maybe I will just try the fix. That way, the next time somebody asks if they should do this I can run in screaming "Don't! Don't! You'll kill us all!"

 

[TeenRocketNerd]

without seeing a picture of the damage, it's hard to say if this would work, but:

is the blown out portion of the tube in an area where you could buy/install a length of bt-60 coupler spanning the damaged area? This would be much stronger than repairing it with a printer paper lining. Then, depending on where the damage is, you could either sand the upper centering ring down to fit inside the coupler (much as you would have to with your other mentioned method of repair). Or, you might be able to simple adjust the upper centering ring down lower, so it rests neatly just below the coupler?


Then, if this much is done, you can simply glue any remaining flaps of blown out body tube to the coupler with ca glue, and fill the damaged area as needed, if you're going to repaint. A new mean machine is in the $20-$30 range, IIRC, I wouldn't blow $12 on decals to fix a damaged one-that's just me.
just my 2 cents... post a picture if you can, that would be helpful.


Travis

 

[Scott_Rip]

I'm at work now, but I'll post a picture when I get home. I like the coupler idea, though. I just need to find one cheap.

 

[DaveCombs]

Make one.

Take body tube of the same size, cut a VERY small strip lengthwise out of it to reduce its diameter, and turn this "seam" where the cut edges meet away from the injured part of the body tube.

I do this to make motor blocks for BT-5s. (In this case, where the ID doesn't matter as much, you can just spiral the tube in on itself.)

 

[TeenRocketNerd]

Make one.

Take body tube of the same size, cut a VERY small strip lengthwise out of it to reduce its diameter, and turn this "seam" where the cut edges meet away from the injured part of the body tube.

I do this to make motor blocks for BT-5s. (In this case, where the ID doesn't matter as much, you can just spiral the tube in on itself.)

I'll echo What Dave said,

although there are two ways to make your own couper:

slit the tube, fold one end inside the other, then fit about half of the "coupler" into a regular piece of airframe and mark the overlap with a pen or pencil. Then, take scissors and cut along the line you just made. the coupler will now be the same diameter as the inside of the tube with no overlap- now glue the strip you cut out to the inside of the coupler for strength-


alternatively:


slit the length of bt-60 tube and slide half or so of it inside the corresponding airfame after you've applied glue to 1/8 to 1/4" of the inside flap of the coupler (here you are not cutting and piecing- you are just re-rolling and gluing)

BRS. hobbies does carry couplers for cheap also...

OT-Dave: motor blocks for BT-5's-why not just cut a 1/4" length of motor casing off of a used 13mm motor?

 

[Scott_Rip]

That's a good idea if I had spare BT-60 lying around. Unfortunately, I have yet to build up a stock of spare building supplies. I did find a paper coupler for $0.50 at Red Arrow Hobbies. The shipping is $6.50, but I ordered some other stuff with it that I've been meaning to get. I'll post before and after pics once I've done the work. Thanks for the suggestions!

 

[DaveCombs]

OT-Dave: motor blocks for BT-5's-why not just cut a 1/4" length of motor casing off of a used 13mm motor?

I'd do that, but at this point I don't actually have any spent 13mm cases! The only flyable 13mm I have right now is my Mosquito, and it hasn't left the Earth yet.

 

[Handeman]

I'd do that, but at this point I don't actually have any spent 13mm cases! The only flyable 13mm I have right now is my Mosquito, and it hasn't left the Earth yet.

What'ch ya wait'en on?:turtle:

 

[DaveCombs]

What'ch ya wait'en on?:turtle:

A free weekend, for one thing... This weekend is a road trip to Columbus, last week was Scout camp, the week before that was a business trip... I'm going through withdrawal!

 

[Handeman]

A free weekend, for one thing... This weekend is a road trip to Columbus, last week was Scout camp, the week before that was a business trip... I'm going through withdrawal!

I hear that. I made it to a launch in July, but the next one I'll get to will be Sept.:cry:

 

[Tom Swift]

I'd do that, but at this point I don't actually have any spent 13mm cases! The only flyable 13mm I have right now is my Mosquito, and it hasn't left the Earth yet.

And when you lose your Mosquito you STILL won't have any spent cases. Might as well launch it tonight from your front lawn and get it over with.

 

[Tom Swift]

Then again, for the sake of somebody having the experience, maybe I will just try the fix. That way, the next time somebody asks if they should do this I can run in screaming "Don't! Don't! You'll kill us all!"

:lol: THAT brought someone to my office to ask what I was laughing about!