Help!

[rbeckey]

Guys, I've been building off and on for thirty years. I've built every skill level more than once, but I'm having a very hard time right now with my ACME SPITFIRE! I cannot get the half in, half out thing with the CR no matter what I do. I am trying to assemble the first section, and I can't seem to hold the tube in place, align the second ring and push it in half way all at once. I've been working on it for 30 minutes! I took a pencil and rubbed it along the inside of the tube along the cut to flare it out a bit where the cutting had pushed it in, and I sanded the CR a bit to make it less tight, but I still can't align everything and get that CR just HALF way in. It either goes all the way in, or the one side goes in and the other stays out, or I push the first section tube out of place! ARRGGGHH!

 

[n3tjm]

The tubes do not have to be perfectly centered on the ediges of the centering rigns. Just have it to hold the tube in place. Then let the glue dry, add the nezt tube and centering ring, align, glue, let dry... and so on. The most difficult one will be the top ring.

 

[rbeckey]

I came up with a solution, I hope. I carefully aligned the tube and the first CR and pushed it into place. I then put a small bead of 5 minute epoxy along the BT/CR joint. I then pushed the second CR into place at the end of the first section of tube, without worrying about a perfect half in half out fit. I DID NOT glue this. When the first CR/BT sets, I'll worry about the half in half out bit, get the secongd CR where I want it and glue it. When it sets I'll do the same all the way up. This way I'm only trying to align one part at a time.

 

[jflis]

I've received a few comments (not many though) about the complexity of that part of the assembly steps.

I need to review how I word those steps and add words to the effect that this "half in/half out" on the centering rings is *not* as critical as it sounds.

The *primary* purpose of the centering rings is two fold.

1) provide strength to the joint (which it does even if it is flush with one tube or the other (sure it would be stronger if it spanned BOTH tubes, but there is enough strength added even when flush))

2) assure the *roundness* of the body tube at the joint (which it does even if it is flush)

Understand, one of my early prototypes (which flies fine) doesn't even HAVE these rings. But, without the rings it is a REAL bear to build. I added the rings to ease the assembly, not make it more complicated.

I also realize (for this and some other kits) that I need to put a hints/tips section on the web for each kit cuz these are great questions and the answer would help everyone!

jim

 

[powderburner]

rbeckey,

I have only put together one of my Spits, and I definitely remember having a little trouble with what you mentioned. I think the next one I build will be done differently.

I will go ahead and recess the CRs a teeny bit into the top of each section of BT, maybe by about 1/32 or so. I plan to use balsa scraps to cut little blocks or tabs, and glue them around the perimeter of the CR in 6 or 8 places, sticking up above the joint by maybe 1/16 (1 or 2 mm for you Brits out there), so the next BT section can use them as 'locaters' and slip over them to sit on the adjoining lower BT edge-to-edge. I am then going to apply a ring of epoxy around the inside of this joint, let it set overnight, and begin to stack on the next (did I mention that I build stuff slower than molasses in January?)

About the only other way to beat this would be for FlisKits to include twice as many CRs in the kit, and put one inside the BT on each side of the joint, but then you will still have an edge-to-edge butt joint between the BT pieces. But the extra CRs would sure hold things in place!?!

 

[Austin]

I have built two Acme's and they went together well. I can understand where there may be some difficulty, but I didn't experience that nor did my Son...but he did have me watching him. I used Alphaetic Resin (Yellow Glue) as it tacs faster and dries faster than white glue. Each ring was placed just inside the upper lip of the respective bodytube, just enough to hold it. This gave more room to insert the bottom of the next tube on, where I wanted the glue joint to be the strongest.

Hope this helps,

Carl

 

[powderburner]

Originally posted by CTulanko
Each ring was placed just inside the upper lip of the respective bodytube, just enough to hold it.

Yeah, that's what I did the first time. I spent a lot of time dry-fitting the CRs in place, tapping this side just so, tapping the inside with a pencil to correct, tapping the first side again . . .

There has to be a faster, more 'concrete', less artsy-craftsy way to do this

 

[swimmer]

rbeckey,

Half in and half out...I had the same problem (?) well, not really a problem. I did the best I could and the joints did not come out perfect. But, after I got my Spitfire done, it is one solid piece of rocket. You'll find out that the joints are secure and rigid when you are finished. Be sure to glue the outside of the joint also.

Just wait till you fly it..........

 

[corpse]

can you push it in from the other side?
push it all the way through the tube intell it comes out were you want it .

 

[rbeckey]

The idea I posted above worked quite well. When the epoxy set, I pulled the second CR and put glue on the inside of the top of the first tube section and the BT 50, then slid the CR back in place, gently tapping it into place, half in and half out. Now it is set and ready for the next process.

 

[powderburner]

rbeckey,

You may have saved me some self-inflicted, unnecessary work on my next Spit build-------Thanks!

Actually, I have been seriously thinking of making the joint deliberately mis-matched, and even cutting the bottom edge of each tube in a crooked pattern and a bit long (to add to the overall 'effect' of the ACME Spitfire) on the outside of the bend; this type of joint could also help hold things together a bit more securely. But it means I would have to mod the fin wrap patterns, and the upper edge of each wrap would have to be tucked under the overhanging tube above it.

 

[rbeckey]

I made a minor mod, doubling the 110 pound card stock in the tail and epoxying the layers together. The result feels almost as stiff as a regular BT. I also put a healthy dollop of epoxy in the point of the NC.
I didn't want to smear the purty printing, so I cut out the printed tail pattern and taped it with double sided tape to a piece of paper. I then taped quarter inch wide strips of paper on the fin attachment points, only taping on the base paper, and taped a mask across the glue tab. I then sprayed it with clear enamel and took off all the masking. That way I was able to wipe up little glue spots, etc. without smearing the ink. I also made a strip of color on label paper and sprayed it, for the strip of exposed BT at the top of the tail cone.

 

[eugenefl]

Originally posted by jflis
I also realize (for this and some other kits) that I need to put a hints/tips section on the web for each kit cuz these are great questions and the answer would help everyone!

jim

While you're at it, since we all know how slow business is , don't forget to add <a href="https://www.rocketryforum.com/showthread.php?s=&threadid=4608&highlight=Nomad">this Nomad</a> thread to the hints page. By the way, when can we expect to see a Deuce's Shrine page? Jim, listen to the voices in your head - "If you build it, they will come..." In your spare time though...we wouldn't want you slackin' on product development.

 

[rbeckey]

New Acme Spitfire ready to fly! (Except for launch lugs. Still thinking that one over.)

 

[jflis]

My God Man! What did you DO to that thing??? It's all, well, crooked and.. man, it just ain't RIGHT!

Lookin' good, dude

 

[rbeckey]

You should have seen the instructions. This madman had me cuttin' a perfectly good body tube, which is not so unusual, but none of the cuts were straight. Took me years to learn how to do a perfectly straight tube cut, now I gotta slice and dice every which way. I put the pieces together as best I could, but this is what I got.
Hey Jim, taking a lesson from Art Applewhite, I covered the inside of the NC with fiberglass wallboard tape and 5 minute Devcon, which doesn't bleed through paper. Thing is as hard as a rock.

 

[rbeckey]

I just had a thought. How cool is it that the man who designed the Acme Spitfire complimented the one I built! That's pretty darn cool!

 

[jflis]

 

[swimmer]

rbeckey,

That is a great looking Spitfire and get ready for a fun time when you launch it.


You probably already do this but I display my rockets using CD's with a spent motor epoxied to the center of it. Works good to take the lean out of the Spitfire when you are displaying it.