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You ever have "One of Them Rockets"?

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Woody's Workshop

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About 5 years ago, my son brought his girl friend over for dinner.
We got to discussing rockets.
Since I was constantly working on the house this was one of the off times from rocketry.
We dug out my stuff, pulled out the old trusted Wizard and put it up a few times.
After they left, I got to thinking what a great little rocket that was.
I wondered how a bigger version would do.

So I sim'ed an upscale. And one a little larger, and larger, and larger.
So now I've made several sim's, and they all did well after fudging around with different Engines.
So on with the builds.
BT-50, BT-55, BT-60, BT-70, BT-80. Even a downscale to BT-5, and a BT-20 mini engine.
Now, I had a little trouble with the BT-70. I tried to use Great Stuff to foam the can.
That didn't work out so well, so I ordered another EM and tube. Problem solved.

In the process, I lost our house, the wood shop and all.
Everything was packed in boxes and put in storage at my buddy's old farm house.
Couple years passed and I finally got to dig out my rocket stuff and set up a little shop in the master bedroom here in the apartment.
When I pulled the BT-50 18mm EM Wizard out of the box...one of the fins was split all the way to the fillet. No other rocket was damaged what so ever.
Cut a new fin, applied several coats of TB, sanded smooth, glued it on and did the fillets, sanded all nice and smooth.

Then, someone brought bed bugs into the apartment.
Had to box everything up again and take it out to have the place heat treated.
Few weeks ago, I got that same rocket out of the box, and I'll be Danged if one of the fins wasn't all gouged up and nicked.
Didn't feel it was bad enough to replace the fin. Patched up the fin wood filler, coated with TB and sanded smooth.
At this point I was a little afraid that the balsa I had used might be too soft, I decided to paper the fins.
Cut a template, papered all the fins so they overlapped on the edges, and applied several coats of BT.
Sanded it smooth, but went through in a few places, so I decided I needed to add a couple coats more.

Got up the next day, and I'll be Danged, if the friggin paper did delaminate! ARRRGGGG. Wrinkles and bubbles all over the place.
So, I took the ol' Xacto knife out, cut down the edges and peeled the paper off, and all the TB down to the base coat.
That should have rang a bell, but I kept going.
When I was done, I sat the rocket down, and it slowly twisted and fell over.
All 3 fins were cracked just at the top of the fillets, now totally useless.
Now I face the terrible fact of carving those nice fillets off, to make and mount 3 new fins.

I am thinking this rocket is an omen or something.
Maybe I should make the fins out out of plywood, like on all of it's bigger brothers?
Or should I use balsa, use Epoxy instead of TB for all the procedures mentioned above?
Or should I put what's left in the trash can and start over?
Should I just forget about this one?
Or is it telling me to switch to BT-56 size tube?
Although, I would have to find, or custom order a matching nose cone in balsa.
This is just, "One of Them Rockets" that plague you every now and again.
 
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dhbarr

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Stick a d21 in there; if it survives, it's a battle-scarred vet worth saving. If it shreds, it didn't have guts and/or moxie.
 

Zeus-cat

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I hate to be picky, but your post is very difficult to read; at least for me. Can you use the Enter key a few times to make it into paragraphs?
 

Steve Shannon

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I hate to be picky, but your post is very difficult to read; at least for me. Can you use the Enter key a few times to make it into paragraphs?
I see paragraphs. Maybe he edited it after your post?

I would pitch the rocket and start over. When you're in a hole, stop digging.
 

Woody's Workshop

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Against the popular advice to give it up...
The other night I decided to cut new fins from balsa.
Sanded all to size, leading edge tapered, everything mounted in the fin jig.
Then I noticed it...I cut the fins wrong to the grain of the balsa.

Tonight I cut another set of fins out (the correct way) and they are ready to go on.
Just sitting here trying to decide weather to go TiteBond, or Epoxy.
It's only 18mm engine mount, but I'm thinking I'd better go more bullet proof.

Since I can't sleep, it would be faster to use epoxy.
Then again, I have several other projects that need attention.
And I am getting anxious to start the build thread on sanding TiteBond.
But no batteries for the camera.

Just one delema after another...
 

Kruegon

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Just me, but this would be my tactic at this point…

Cut new fins. Cut new body tube. Cut new lug. Salvage nose, MMT, and shock cord. Rebuild.

We all do our fins differently. If you don't currently, you may find that CAing the edges helps greatly with fin split.
 

tomsteve

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"Just one delema after another..."

I believe von braun had that same experience for a while.
 

Woody's Workshop

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Hear I go again.
Sanding the fillets on this Wizard from Hell, and I notice they ain't centered.
Like gravity pulled them to side. So I look at the engine mount end.
Damn, I glued the fins on right over the center of the lines, perfectly.
Only thing is, I must have marked the lines off center and should have lined up one side of the fin to the line.
Oh well, I'll finish it. Just won't decal this one. I'll build another for the decals.
I guess it got the best of me this time, what can I say?
 

HHaase

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I have an estes Ricochet that's become 'that kit'. Flown it a dozen times now, each time it's popped a fin.
At this point I think it's more epoxy than cardboard and balsa. Looks atrocious. But at least the darn fins stay on there now!

Mainly I just keep flying it because I have it set up for split recovery and it's good for a 'first flight' of the day to judge wind without travelling too far.

-Hans
 

byoungblood

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I have an old Estes Sizzler from the 80s that I can't keep fins on. When I built it around 87-88 time frame, I launched it probably 3-4 times and it popped a fin. Glued it back on, popped another one. Taught the Space Exploration merit badge when I worked at a Boy Scout camp in the early 90s and launched it weekly there. Popped some fins at least a couple more times.

Put it away and stored it for a number of years, and when I got it out, all the fins had popped. Went back and made some replacements, sanded down to the bare tube, and before I could even launch it again, it popped one of the fins I just put back on. It is still sitting on my workbench, forlorn, with only one fin on it. I want to fly it again, since it and my Bullpup are the only two surviving rockets from my younger years (if you don't count the couple I have in various stages of completion) but I may just call it quits and retire it for good.
 
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