Goldfinger II: Built! Flown!.......repaired

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Nytrunner

Pop lugs, not drugs
Joined
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Anyone who's got the Tandem-X launch set knows the Crossfire ISX. I love these little things. The original Goldfinger accidentally went to Florida with a friend three years ago so its time to rebuild. (Built a couple with more conventional finish in between, 1 disappeared in the clouds, the other has flown on A B and C without incident as I learned when not to launch)
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I saw a Tandem set on ebay for $10 because the owner (not a rocketeer) thought a couple tube wrinkles would make it unsafe. My gain!
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The plastic aft nozzle is easily liberated with a hacksaw blade and cleaned up with 220. Slotted tubes make marking the motor mount a piece of cake and a spent C6 helped make sure everything fit properly.
Time to glue up and forget for awhile
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Next post: Fins!
 
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I've been on an airfoil kick sine my L1 build. I don't have access to a floor mounted belt sander anymore, but balsa is conveniently easy to do by hand (I'll just postpone plywood foiling till I buy/borrow a sander). I won't say their a perfect superellipse, but they're close enough for me.
The thin trailing taper is a little flexy, but superglue will fix that.
Does anyone else think those mini fin attachments look like little millenium Falcons? I can't shake the thought.
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Second time using superglue to seal balsa fins, and I like it. It seals the fins a bit, makes finishing a little easier, and stiffens the fins a tad. Never had to coat such a tiny piece so the pliers were invaluable.

Now to fill spirals and try to do something about those tube wrinkles.
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I've had tube wrinkles like that before. I put a mandrel inside to keep the tube straight, a little CA to firm it up, and then filler the outside. Flys just fine.

Same thing occurred to me when I built mine - those ARE little Millennium Falcons. Just without the cockpit.
 
What happened to your Tube?
Maybe harden it from the inside with CA than sand it from the outside?
You could probably still peel away the 35 ounces of glassine layer if you are careful, then harden what's left with CA before a sanding and a wrap of .75oz. FG cloth. That would keep you under the listed weight for the Crossfire if you go light on the paint.
It's one of my favorite designs, and I have a few of them, in various ways of being built.
 
What happened to your Tube?

It came that way. The original owner was worried about it so they put the launch set on ebay for ~1/3 the original price. I figured I could fix it up. And you'll love the paintjob :cool:

Definitely giving the CA/sanding a shot. Thanks!
I haven't glassed a tube before, so I don't think I'll test it on such a small tube. But that is going in the Future Folder for sure.
 
I've had tube wrinkles like that before. I put a mandrel inside to keep the tube straight, a little CA to firm it up, and then filler the outside. Flys just fine.

Same thing occurred to me when I built mine - those ARE little Millennium Falcons. Just without the cockpit.

Mandrel, mandrel, I hope when you say mandrel you mean D motor on a stick cuz thats what I've got at hand lol.

And thank god, I was hoping I wasn't just seeing things in anticipation of Rogue One.
 
Mandrel, mandrel, I hope when you say mandrel you mean D motor on a stick cuz thats what I've got at hand lol.

And thank god, I was hoping I wasn't just seeing things in anticipation of Rogue One.

I've made a mandrel from spent D Motors before, gluing them together, then sanding them smooth, and using filler and primer to build them up to the required dimension. Worked out great. I ran a piece or 1/8" launch rod through the exhaust nozzles to get them all stacked before the CA was applied. Great 24mm Mandrel.
 
The tube sanded down pretty nicely, but the wrinkles aren't completely covered yet. I'm calling an end to the filling phase and will revisit the surface during the prime/sand cycle.

Motor mount is set in place, nozzle went on smoothly, and the motor hook is free to flex. Figured I'd use the filler one more time to smooth out the nozzle/tube seam.
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I usually tack my fins in place with a couple dots of super glue. With the mini-Falcons in place its time for Elmers fillets! I usually repeat the fillet application a couple more times.
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With the first round drying overnight, I thought I'd take a naked-rocket picture. And in the process, the picture helpfully pointed out that my launch lug was still unattached... That has been rectified.
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I'll either get a second fillet round on in the morning or after I get back from work. May be able to start priming ~wednesday.
 
It looks great. Don't sweat the small stuff or hurt your head over it, it will fly better the less you add anyway, and it has a pretty good chance of not being your first Crossfire ISX, especially if you plan on using the "Rocket go Bye-Bye" Chute' provided in the kit.
 
Thanks Top!

I've some good success/luck using spill holes to decrease the drift for little guys like the crossfire. Although I'm considering adapting the spill hole cutout from my White Sorcerer II (Est Magician) to make an 6-8" parachute (haven't measured that cutout yet) and try it out on a lightweight rocket. If I did, it'd be my other crossfire, Redcross II.
 
Laid some larger radius Elmers fillets and left them to dry while I went to see Hacksaw Ridge with some friends. I'm more of a Marvel/DC fan so it was rougher than my usual theater trips, but its a very well done movie. Good historical callbacks for WWII buffs also.

I really need to sleep for work tomorrow, but the election results are keeping me up.....
 
And I have a motor on a stick now! No more painted fingers!
No more absentmindedly smeared noses!
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That tube crinkle is proving pretty resilient, so I doubt it'll go away completely, but I think it may get a little better after a couple prime/sand cycles.
First round of primer raised some fuzzy fibers, so I'll take those down tomorrow and recoat.
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There are a few grain lines visible on the fins, but all I did was a coat of thin superglue so no complaining here. More important to me is that the sealed fins didn't drink the paint in like a camel, and they didn't raise balsa fibers.
 
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I have the same little rocket! Just gotta sand her up and paint her as soon as I get the chance.
Looking great so far!
 
Thanks Colvin! I've only just started putting some work on the finish of my rockets.
While I was in college it was basically "Let me throw it together and launch it whenever I can spare a few minutes", as evidenced by my 1st surviving Crossfire, the Redcross II
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I have the same little rocket! Just gotta sand her up and paint her as soon as I get the chance.
Looking great so far!

The Crossfire is a great flyer. Did you get yours from the Tandem launch set or as a standalone? Fortunately, I've learned how not to lose little high performance models like this as well.
Spill holes (or, as others have pointed out, a streamer) and proper motors for the field will bring it back every time and not make you sad over hours of finish work lost.

Back to updates: Its in round 2 of the prime/sand cycle, so nothing visually interesting to show. I'll do round 3 tomorrow and maybe fix my 3 fin Stratocruiser, but I'll be out teaching some TARC kids about OpenRocket in the afternoon, so the fix can probably wait.
 
I got mine from the Tandem kit.
Between moving all of my stuff around, I lost the decals. I'll do the best I can with what I have left though. :)
The Amazon still exists, but my almost two year old daughter is following in my footsteps and loves it.
I let her have it and walk around making ssshhhhhhhhhh sounds and saying "WOW!!" The occasional stepping or sitting on it happens.
Well worth the sacrifice if you ask me. Pure joy! :D (Plus I'll have a flying friend in a couple more years!)
 
Getting your kiddo interested is fantastic. Hopefully she doesn't grow up thinking they're "lame" in a decade or so.


First Amazon didn't cure properly at the joint section, so at ejection the front separated neatly and continued on a beautiful ballistic path into some woods.

I recently replaced it from the bargain Tandem I got on Ebay. Spliced the Sticker and sprayed a gloss black undercoat with red highlights.
Then I learned a valuable lesson about Rustoleum 2X clear coat. Unlike the colors which I've had success applying 48+ hours after the previous color, the clear coat contains Toluene. To get the previous color cured safely, it needs like a week+ or the Tolune screws it up. Imagine my surprise when I apply a couple light coats and all of a sudden I get these weird scaly patches.
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Fortunately, it couldn't have happened on a better rocket. Amazon sounds wild, Monza sounds like monster (in my head at least) and the irregular, mottled, scaly look of the affected paint fit in with the overall theme. If I tried to duplicate the pattern distribution, I doubt I could. This was pure good fortune. At least I used Acrylic clear on my newly refinished L1 rocket. I would have been pretty irked to get scaly patches on it.
 
Primer is away! After the 3rd primer round dried, I took the opportunity to practice wetsanding with 220, then 500. It felt pretty smooth after that so I went to the paint.
Krylon metallic 18kt gold was what stood out when shopping around for spray paint, so that's what got used.

And now I believe the name Goldfinger (II) makes a lot more sense:
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It was nearly impossible to take a picture without massive amounts of glare screwing with the image. Even changing the exposure just made the room black.
I'll let this cure for a day or so then install the shock cord and parachute.

Also got to go launch today with some HARA club members. I like having a photographer!
Monza flight.jpgRedcross II flight.jpgSAM flight.jpg
Thats the Monza (Amazon), Redcross II (the crossfire that won't die), and my first rocket SAM (Patriot)
 
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Your airfoiled fins look great. I just did mine stock with a rounded leading edge. It's currently sitting on my desk while I add glue fillets to the fins today.
 
Your airfoiled fins look great. I just did mine stock with a rounded leading edge. It's currently sitting on my desk while I add glue fillets to the fins today.

Thanks Tango! The inconsistency of my manual sanding will likely offset any drag reduction, but something about Square corners and airflow just doesn't sit right with me. (from a structural standpoint, neither does wood that I can cut with my fingernail, but it sure is easy to shape!) Now I've just got to buy or borrow a sander to work on my set of Pro Series II fins.

Make sure to post your results in the Crossfire gallery!
 
Make sure to post your results in the Crossfire gallery!

I didn't know there was such a thing. I will :wink:.

I didn't bother with trying to fill seems on this one. The BT seems were pretty tight - I couldn't even get my fingernail to catch - so I think I can get them to disappear pretty well with primer and paint.
 
I didn't know there was such a thing. I will

Here you go. Its in the Galleries forum
https://www.rocketryforum.com/showt...ire-ISX-(-1469)-Gallery&p=1637673#post1637673

Now for one last little build detail: the parachute......
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Forget where I read it, but someone recommended pre-crumpling the parachute from each attach point to help it pack and unfold better. Why not?
This looks like a ~2.5" radius spill hole job.

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With that, I should probably mark the thread finished. I have no clue when this is going to fly for the first time.
Thanks for reading! (Now I have to go buy more Elmers and Epoxy. I seem to have run out)
~Nytrunner
 
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I wouldn't call it finished yet... Not until the maiden flight. :wink: And for some reason, your last attachments didn't attach. At least I can't see them :(.
 
Well the forum agrees with you, because I can't seem to figure out how to edit the title.

And those are special Thorshammer photos. Only the worthy can see them.:cool:

*as a side note, the golden crossfire on a dowel makes a really nice Rocket-scepter*
 
Had a little incident on landing. I now feel silly for saying such a tiny rockey had nothing to worry about on recovery.
My guess is that the primer coats and heavy metallic paint combined with a generous spill hole to create the scene below.
My sister retrieved it and didn't even notice the missing fin, so there was no hope of finding it after the fact.

Oh well. I have a balsa sheet that I could probably repair it with. But....so shiny, so young, so full of potential, (and apparently so overweight...)
Also, there is a very stiff edge and shell of paint in a couple places which I find amusing.

I also crammed an Estes altimeter (Estimeter?) in there too. Maybe that screwed with the chute and line arrangement during deployment too.
To add insult to injury, I didn't even turn it on.

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Even though the flight ended poorly, I was reviewing my videos and discovered I caught the exchange trying to teach my mom how to use the launch controller.
I've been doing this for almost 4 years nd this is the first time I was able to get her out (since I don't know when I'll be back down again).
She really enjoyed it :)

[video=youtube;JmzKUkrnV1w]https://www.youtube.com/watch?v=JmzKUkrnV1w&feature=youtu.be[/video]
 
I love how Mom's reaction is just like everyone's first reaction, "That is so cool!" :lol:
 
So her experience with launching rockets is purely old spring loaded toys she remembered from the Gemini/Apollo days. I think those maybe went 20'. Let's just say she never had a handle on what my hobby entailed till now
 
Repairs underway!

I'm partially regretting putting a good fillet on it. If I hadn't the fin would have just popped out.
This incident pulled up paint, snapped the fin, and started tears in the body tube.

Now to see if I can have it back together in time to fly Saturday at Birmingham.....
received_695346280644056.jpgreceived_695353930643291.jpgNeed to knock that corner down a little.
 
I'm looking for something like this for my first project, Would you guys recommend this model?
 
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