Wildman Rocketry Giveaway!


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  1. #1
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    6th June 2010
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    My quest for a perfect Fin Gluing Guide (FGG)

    Hi folks,

    After two years as a BAR, I still don't reliably get fins on my LPR rockets in a reliably perfect manner, particularly when there are multiple fins in line (like main fins plus higher canard fins).

    I have built bevel fin guides:

    Click image for larger version. 

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    And found them good but inaccuracies in construction techniques in my hands mean that while my fins are straight with respect to the long axis of the tube, and multiple fins (main plus canards for example) are coplanar, sometimes I'm off noticeably in that the fin plane doesn't intersect with the center of the tube. Further, the way I built it, if the canard fins are far up on the rocket there's not really room to attach them. I can think of design changes to address this, but I've found I prefer a tool that lets me get all three on at once.

    I've also bought and beefed up the Estes fin tool, by putting a solid 1/2" bolt in it for greater center mandrel stability:

    Click image for larger version. 

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    It's a good starter tool but I'm looking for something beefier and that has better vertically-stable guides for the fins. I know that variations on the theme Estes chose are commercially available, and would probably suit me well. But, I really wanted to build something I could adapt as my needs (and whims) change.

    And so, it begins.

    I will document my efforts here. I think I'm about 80% complete, and just haven't had time to document things. Stay tuned, over the coming week I'll document my stuff here. Let's see how it turns out!

    Stay tuned!

    Marc

    Thou shalt not violate causality within my historic light cone. Or Else.
    NAR member 92906

  2. #2
    Join Date
    19th January 2009
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    Marc
    Likely reason your fins are off center may be because your either not using the proper size fin stock shim Between the 45 cut Bevel blocks or there was a mistake setting up the jig or choosing the fin thickness material.
    It's really hard not to get fins centered, even heavily tapered fins, on the body tube with the use of the correct spacer shim.

    You are using spacer shims between the beveled plates of your fixture aren't you?

    Another point to remind ourselves is that Nothing on earth is ever Perfect. We can make things work very well but we're never completely satisfied with our work. Rememeber "Rocketry is Fun...damn it"

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Last edited by Micromeister; 15th February 2012 at 01:40 PM.
    Keep em Flyin Micronzied
    John
    Mrcluster/Micromeister
    Nar-15731
    Co-moderator MicroMaxRockets yahoo group.
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    Narhams Section 139 - ROMCC

  3. #3
    Join Date
    26th October 2011
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    South Shore, Massachusetts
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    Something Ive seen

    I have seen "lazer" lines down the tube and the like to make sure you get a fin on straight.

    Ive seen the toy lazers for a few dollars, and in my opinion a straight line is a straight line.

    If you got 2 of them and spaced them at the top of the tube facing the back end, and used them for each side of that fin.

    Id trust a lazer light over a level personally.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  4. #4
    Join Date
    18th January 2009
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    Orlando, Florida
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    I'm designing a new Odd'l Rockets fin alignment tool as we speak.
    Sorry - no pictures yet! Top Secret, ya know.
    It'll be best suited for LPR models from a BT-5 to BT-60. Beyond that, most MPR builders make their own jigs out of foamboard.

    This thing will lock in the engine mount and automatically center the engine hook between two fins, either 3 or 4 fin models.
    1/16", 3/32" and 1/8" fin thicknesses will work.

    Is it perfect? No. It won't hold a second fin above the larger fin below it. (That's what clothes pins and popsicle sticks were made for.)
    It's not designed for anything above 4 finned models.

    But - it will "lock" in the engine mount and hold fins for gluing alignment, radiating from the centerline of the body tube.
    In the prototypes I've had made, I'll insert the tool into finished rockets I've built.
    These were rockets where I thought the fins were equally spaced by "eyeballing" it. All of them were off!

    It will be affordable!
    It's close to being bagged up.
    I'll make an announcement when I get it just right!
    Hans "Chris" Michielssen
    Old/New NAR # 19086 SR

    www.oddlrockets.com
    www.modelrocketbuilding.blogspot.com
    http://www.nar.org/HowToBuildAModelRocket/index.html
    Your results may vary
    "Nose cones roll, be careful with that."
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  5. #5
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    Quote Originally Posted by hcmbanjo View Post
    I'm designing a new Odd'l Rockets fin alignment tool as we speak.
    Now that sounds interesting. If you're going to manufacture and market it, well, I'll be compelled to check it out.

  6. #6
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    22nd September 2010
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    Tarpon Springs, FL
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    Chris...hope to see you this Saturday at TTRA.

    You may want to consider making this device in LPR, MPR, and HPR versions. Or offer the LPR one in plan form and allow the user to upscale it to whatever diameter he/she needs......I would consider one!!!

    Terry


    Quote Originally Posted by hcmbanjo View Post
    I'm designing a new Odd'l Rockets fin alignment tool as we speak.
    Sorry - no pictures yet! Top Secret, ya know.
    It'll be best suited for LPR models from a BT-5 to BT-60. Beyond that, most MPR builders make their own jigs out of foamboard.

    This thing will lock in the engine mount and automatically center the engine hook between two fins, either 3 or 4 fin models.
    1/16", 3/32" and 1/8" fin thicknesses will work.

    Is it perfect? No. It won't hold a second fin above the larger fin below it. (That's what clothes pins and popsicle sticks were made for.)
    It's not designed for anything above 4 finned models.

    But - it will "lock" in the engine mount and hold fins for gluing alignment, radiating from the centerline of the body tube.
    In the prototypes I've had made, I'll insert the tool into finished rockets I've built.
    These were rockets where I thought the fins were equally spaced by "eyeballing" it. All of them were off!

    It will be affordable!
    It's close to being bagged up.
    I'll make an announcement when I get it just right!
    TRA 11835 L3
    NAR 68877 L2 (lapsed)

    This offer not good after curfew in sectors R or N.

  7. #7
    Join Date
    6th June 2010
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    Infected by my kids with some virus, I had two choices this afternoon:

    -Go home sick and work on my FGG, or
    -Turn into a zombie walker, infecting whoever's brains I chose to eat.

    I went with option number 1, though brains do make me feel better.

    I titled this a quest for a perfect fin gluing guide. Let's talk about what I mean by perfect, in the context of this thread.

    I want my fins to go on visually perfect with respect to
    1. Being straight with the long axis of the body tube,
    2. Be at the right angles to the center line of the tube,
    3. Be aligned in a plane with the center line of the body tube, and
    4. When there are multiple fins in a plane (staged rockets, or canard fins...), I want them all properly coplanar.

    From an ease of use perspective, these are my objectives:

    A. I want certainty when I attach a fin that it is going on right. This is an issue I had with the bevel jig... it would look right, but then when I put on the opposite fin (on 4 fin rockets) it wouldn't be in the same plane. Grr.

    B. I don't mind doing some adjustments for different fin thicknesses and the like, but it shouldn't be an onerous task. The Estes jig was inspired in my opinion, in that you change fin thickness with a simple reversal of the vertical tabs. I won't be able to make it that easy, but a guy can dream, can't he?

    C. I don't want to be worried about disturbing fin #1 when I am putting on fin #2. This translates to the system needs to be pretty rigid.

    (to be continued)
    Thou shalt not violate causality within my historic light cone. Or Else.
    NAR member 92906

  8. #8
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    Quote Originally Posted by Micromeister View Post
    Marc
    Likely reason your fins are off center may be because your either not using the proper size fin stock shim Between the 45 cut Bevel blocks
    Nope, I always use material exactly the right size, coming from the same sheet or scraps from the laser cut set, sanded if needed to match the actual fins.

    Quote Originally Posted by Micromeister View Post
    or there was a mistake setting up the jig...
    Ding ding!

    While the angle (typically 45 deg) of the jig isn't critical, it is important that it be uniform across the whole length, and identical on the top and bottom parts. I don't think I got it as uniform as it should be, as I was using a circular saw (don't have a table saw). I used an edge guide to improve uniformity but was probably far from perfect. Also, the dowels and such that hold top and bottom together (with shims in between) didn't fit quite perfectly. A small error here actually has a big effect on getting the fins in the right plane.


    Quote Originally Posted by Micromeister View Post
    We can make things work very well but we're never completely satisfied with our work. Rememeber "Rocketry is Fun...damn it"
    True!
    Thou shalt not violate causality within my historic light cone. Or Else.
    NAR member 92906

  9. #9
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    My definition of perfection is thus something to the effect of "the jig has to go together without any visual [to me] error, and any non-visual error should be small enough not to effect the final visual look of the completed rocket, in the ways I've defined above."

    I'm not a great fabricator (unless I'm explaining to my wife why I needed to place yet another order for stuff [but honey, C11-3 and C11-5 AREN'T the same thing...], but I've been in the mood to build something.

    So let's get started. The first thing I would need is a base on which to construct the FGG. This implies a flat piece of lumber. I had none at home

    Off to Lowes. I expected to come back with something made out of dense particleboard or other "not quite real identifiable wood" product, as the closer you get to single plank, the more warping you can expect.

    But what I came back was an 18"x36" piece of Aspen. It was made of several planks edge glued together:

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    I chose this because it was ideal dimensions (I wanted something ~16" wide at least, to handle a good fin span, and this is a good width to be able to cut on my compound miter saw), in that I could cut it in half and make TWO guides eventually, assuming I would screw up the first and refine the design on the second.

    It was also the flattest thing I could find that was already pretty close to my desired dimensions, and which didn't cost a mint. I think it was on sale for ~$14, which is still pricey, but it looked good, was dead flat, and I grabbed it.

    I also bought angle aluminum stock at 1/16" thick, 90 degree, 2" on each side. You'll see pictures of it soon enough.

    Onto my cart also went a long piece of 1x2" poplar. Again, I didn't really care what it was, I just wanted it to be about the right size and a good straight piece of lumber.

    Assorted other fittings were purchased as well; we'll get into them in good time.

    I started on the base. The first thing to do was cut the 18" wide x 36" long base material into two 18" square (approximately) pieces.

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    Oops. I forgot, the reason I liked 16" is that my saw can cut it easily, if I do one pass on each side. 18" is just a bit too big.

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    That's OK. I got out my electric scroll saw and cut the remainder. Then I used my disc sander to polish the area where the scroll saw kerf didn't match the miter saw kerf. I got nice clean edges. Yea!

    Some quick measurements resulted in pieces cut to fit under the base, to raise it a bit and give me room to work under there. Also, the pieces will help maintain a flat surface:

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    I used drywall screws that I had around, after pre-drilling holes including countersinking so the screws would be flush with the surface:

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    I checked it with a straightedge and was delighted that it was flat in both dimensions. A "perfect" surface to start off my project. Hooray!

    Thou shalt not violate causality within my historic light cone. Or Else.
    NAR member 92906

  10. #10
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    In the last picture above, you will see a printout of a fin guide from BSD Rocketry. I used this to guide my lines drawn onto the surface of the FGG. I sweated these lines like you wouldn't believe. The BSD guide has the 90 degree ones not quite in the same line (they are parallel but slightly offset). I corrected for all this, made sure they all radiated from the same point, and double-checked with a protractor.

    Satisfied that it was perfect (remember my definition!), I put a hole in the center with a narrow bit and countersunk it a bit to make it a good start for a 1/2" inch bit. Inspection by eye and straightedge confirmed that the hole was perfectly positioned. Here's a shot, which also includes protective eyewear. If you try this at home, be sure to protect your eyes when using tools, folks!
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    I test-fit the 1/" all-thread. As expected, it was a bit loose. A 1/2" bit in soft wood makes a slightly larger than 1/2" hole. A few wraps of masking tape (1.5 wraps, I think it was) made it a snug, perfectly centered fit. I used a washer on the back-end and a nut to hold it in place:

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    On top, again a washer and nut were used. Note, the washer is not perfectly centered (and doesn't need to be, and I might swap it out anyway with a smaller width one).

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    I measured with my a L-square and found that the all-thread is perfectly perpendicular to the perfectly flat base. I measured it at several points around, and it is square in all dimensions. Ye-ha!

    Thou shalt not violate causality within my historic light cone. Or Else.
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  11. #11
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    I'll also note that the all-thread is stiff and doesn't deflect much if you push on it. This means, after attaching fin #1, I don't have to worry much about disturbing fin #1 as it dries while sticking on fin #2. Rigidity is good, here.

    To make a good fit for rockets to mount on the all-thread, I put on a good wrap of masking tape on the all thread until a BT-5 tube fit snugly and with no slack, but not so terribly tight it would bind. So, now I have all-thread with tape snugging, and exposed BT-5 as the fundamental mount.

    My first project will be a STarship Vega, with a BT-50 body tube, so I used about 5 BT-5 to BT-50 centering rings to make a good snug slack-free perfectly centered tube-on-guide setup.

    Click image for larger version. 

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    As a side note, the centering rings I used are sort of a black fiber and they got black stains on my hands. What's up with that? Not sure what source I got these from, but they are messy as heck.

    For my next trick, I wanted to make perfectly vertical, rigid supports to rest the fins against. For me, the big downfall of the Estes guide is that the plastic tabs used are too flimsy to hold a perfectly vertical aspect (and, the design doesn't allow them to start off as vertical as I would like... but they do well for a ~$15 guide!).

    The aluminum angle stock (1/16", 2"x2") was chopped with my Compound Miter Saw (with its thinnest blade with most teeth) and resulted in some 4" lengths.

    I had this idea of creating a line of 4 holes in the aluminum stock, one every inch, and a corresponding line of inch-spaced holes in the base, say maybe 8 or so, to allow me to move the stock back and forth, using screws as pegs... I designed it for 1/" fin stock and was going to use cardstock shims for thinner fins Here's what it looks like with just the first four holes:

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    It actually looks OK in the picture, but what I found is that I couldn't reproducibly put the holes in the aluminum in PERFECT positions, and get them to match up with holes in the base, and get the aluminum to be at exactly the right distance from the fin center line I'd drawn. FAIL.

    Click image for larger version. 

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    Thou shalt not violate causality within my historic light cone. Or Else.
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  12. #12
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    New plan:

    Just use two holes in the angle stock, and the holes are much larger now, using a 5/16" bit I think (big holes covered by washers in the picture), and use washers and wing nuts to snug down the screws, allowing fine positioning of the angle guides to suit different thicknesses of fins.

    My eye is able to line up the angle aluminum and a sample fin from whatever kit such that the center line (a thin pencil line) goes right through the middle of the balsa. No problem. Then I snug down the wing nut and I'm done. Takes me about 1 minute per guide in practice, and it gets the guides perfectly aligned to be where they need to be, and requires no precision at all in the placement of the holes on the base. I'm getting better at figuring ways to use imprecise building techniques that nonetheless allow perfect results!

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    Here's the action area:

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    The next little while was spent putting holes at the correct locations (more or less, within a millimeter or so of ideal, but precision not required) every inch or so parallel to the fin lines:

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    OK, that's enough for now. This will continue tomorrow, with tales of sadness and great joys.

    Marc
    Thou shalt not violate causality within my historic light cone. Or Else.
    NAR member 92906

  13. #13
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    In the time it's taken you to do that... I might have gotten the five pieces of lumber cut. This is interesting.

  14. #14
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    Quote Originally Posted by foamy View Post
    In the time it's taken you to do that... I might have gotten the five pieces of lumber cut. This is interesting.
    Hee hee. I started it on Sunday. I'm almost caught up documenting. Today is a half-day for me since my son was sick overnight and I'm partially working from home. I'll have a few moments here and there around teleconferences and deadline and such to document stuff.

    Since the Starship Vega is my first build with the jig, here's a mock-up of the fins in the jig ready for gluing. In reality, I haven't prepped the fins at all, and these particular fin guide tabs are too low (so, the fins don't look to be at the proper height on the tube). But I wanted to see if it was "basically working" so I set it up:

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    Success!!

    For rockets where the fins can be guided at the low point, I'd say it's ready for use. However, most rockets I do may need tabs that go higher.

    At this stage, I had a plan. But I got a bit overconfident:

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    Thou shalt not violate causality within my historic light cone. Or Else.
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  15. #15
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    13th February 2009
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    That is a stout looking fixture, good job. Very creative!
    The process is continuous...

  16. #16
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    Where was I?

    Oh, yes. Pride goeth, before a fall.

    I snapped another reference pic of the mockup, and admired it:

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    Actually, this part is just fine.

    But I had also chopped some 8" lengths of the angle aluminum:

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    And used epoxy to attach them to some scraps of wood into which I had drilled holes for mounting:
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    I thought I was all slick. I had checked to see which of the sides was the most perfectly vertical, to give the best surface to rest the fins on, and marked this, and glued on the wood scraps oriented to allow these perfectly vertical sides to be fin-adjacent.

    After the glue was dry, I test fit on on the jig:

    Click image for larger version. 

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    Gonna be pretty hard to attach clamps, seeing as I have the other face sticking OUTWARD instead of INWARD. D'oh.

    Click image for larger version. 

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    Thou shalt not violate causality within my historic light cone. Or Else.
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  17. #17
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    A few indelicate words were uttered. Oaths made.

    But I remembered my inspiration: perfect alignment.

    Click image for larger version. 

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    I set aside the original longer set (I will use them later, never fear), and chopped the remainder of my angle stock into ~11" lengths, completely using it up.

    Again, I de-burred it, using emery cloth, which is a very important step I failed to mention previously. The cut edges are sharp, and big enough burrs may be present to impact alignment.

    I made sure to align the angle stock correctly with respect to how it's going to be used on the jig, and checked alignment / verticalness of just the stock sitting on the table, which can be considered reference-flat:

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    Notice in the above pic the uniformity of light getting between the L-square and the angle stock. That's vertical, baby. Not all were quite so perfect but they were pretty darn good.

    I glued these to wood, as before. Here's the two best of them, side by side:

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    Oh, so perfect.

    I'll remind readers that primates don't always react well to perfection:

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    Leads to:

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    Thou shalt not violate causality within my historic light cone. Or Else.
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  18. #18
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    I noticed that the big fender washer I used on top made it impossible to get the planar surfaces of my guides close to a BT-50 tube:

    Click image for larger version. 

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    This is inconvenient when smallish fins need to be attached. So let's replace the big washer with a smaller one. I wound up using a lock nut that I had on hand:

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    Using the L-square, I checked it in both dimensions and it appears to be "perfectly" veritical. Keep in mind there's a big washer on the underside of the platform, complementing the smaller lock-nut surface contributing toward verticalness (verticality?) of the all-thread (which, you can see here, is covered in a bit of tape to make it fit well with the BT-50 I cover it with).

    That done, I re-installed my guides. Two of them are perfect. But one, not so much:

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    Over the 11" or so of the guide, it is off by about a millimeter and a half. It's flawed. Imperfect. Ridden with error. I was kind of tempted to go on a rampage like Nomad in the original Star Trek episode "The Changeling."

    I believe this has to do with the way I glued on the wood supports, as the guides seemed true beforehand. Nonetheless, this thread is about accepting imperfect fabrication techniques to nonetheless result in perfect functionality. So I pressed on.

    Ever wonder about the Coyote in those Road Runner cartoons? If he spent money on food instead of on hand grenades, big wrecking balls, and jet-skates, maybe he wouldn't be so hungry for the road runner. And, if he would analyze his failed attempts and adjust them a bit, I bet he would be dining on road runner burgers in no time. But I envy his dedication to his task, and his ingenuity.

    The bottom line is: I planned for errors in the vertical guides. I didn't figure I could cut or glue them straight, so I was a bit surprised when two were perfect.

    The solution is easy: a couple tape strips on the edge of the wooden support:

    Click image for larger version. 

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    The result: Perfectly vertical guides with respect to the surface of the platform and the body tube:

    Click image for larger version. 

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  19. #19
    Join Date
    6th June 2010
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    And I discovered this handy trick to get the guides perfectly aligned with the proper angle to the tube:

    A clear straight edge is aligned against the guide surface. Since it's clear, I can see through it to the reference line representing the intended center point of the fin material. The straight edge is long enough that any deviation from parallel is obvious and easily corrected before tightening down the wing nuts. Takes less than a minute per guide!

    Click image for larger version. 

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  20. #20
    Join Date
    18th January 2009
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    Quote Originally Posted by Marc_G View Post
    ..... I was using a circular saw (don't have a table saw). I used an edge guide to improve uniformity but was probably far from perfect. Also, the dowels and such that hold top and bottom together (with shims in between) didn't fit quite perfectly. A small error here actually has a big effect on getting the fins in the right plane.
    Could be worth it to find a friend with a decent table saw (and who knows how to use it) or even a local cabinet shop. A $10 bribe and a 12-pack of cokes can go a long way toward getting them to make one 'good' cut for you, and you have your 45-degree-precision-angle-problem fixed.

    BTW, it doesn't actually have to be an exact 45 degree angle, just needs to be the same on both sides.
    This is the country that built the transcontinental railroads, the Hoover dam, the Panama canal, coast-to-coast interstates, and put men on the moon....but we can't build a fence.

  21. #21
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    6th June 2010
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    Exciting times: First Fins!

    Alright. The guide is ready for use. All three of the guides have been leveled and they are positioned well.

    Click image for larger version. 

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    For clamps, I got some adjustable pressure clamps, and supplemented their tips with some weather stripping material so that the clamp surfaces wouldn't be at risk of denting the balsa.

    Click image for larger version. 

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    The fins were put on with Elmer's Carpenter's Wood Glue with standard double glue joints. Here are some pictures. Notice, I purposefully attached the fins offset from the lines I drew, so I could use the lines for reference without having them covered up by the fin material.

    Click image for larger version. 

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    The jig was very stable and adding additional fins didn't budge the tube with prior fins already attached.

    Click image for larger version. 

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    Last edited by Marc_G; 31st July 2012 at 03:38 AM.
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  22. #22
    Join Date
    2nd January 2012
    Location
    Washington D.C.
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    Fin Alignment Jig

    I just built this thing today. It seems to work well - it's based on the "guillotine" on the Apogee website.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  23. #23
    Join Date
    21st January 2009
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    Nashville TN USA
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    I see what you have (I have the same exact fixture in the shop),is there a need to mark the tube ?
    Andy

  24. #24
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    2nd January 2012
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    Quote Originally Posted by Stymye View Post
    I see what you have (I have the same exact fixture in the shop),is there a need to mark the tube ?
    Andy,

    One advantage to Marc's kick-ass jig is that (technically) it doesn't require marking the tube. Unfortunately, my jig absolutely requires marking the tube, both to set the jig to true before it's used, and to make sure that the fins are actually at the angles you want them to be at (120d, 90d, etc.). However I have yet to add the small feature of a self-centering "vee" at either end that would simplify the setup process (Apogee's product comes with this feature), and were I to put gauge lines on the outside you might not need to mark the tube - I'll have to experiment with some options now that you mention it...

    Elon

  25. #25
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    6th June 2010
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    So the guide worked great for the lower small fins.

    As I was planning to put on the canard fins and the main fins (which share the same plane, more or less, though the canards are less thick than the mains), I realized that the way I put the nosecones on the main fins before mounting the fins, I really botched my plan, since the guides would either be in too close to the body tube (avoiding the nose cones on the fins, but running into the small fins), or too far out (bumping into the nose cones).



    Then I remembered the first set of guides I built that had the angle aluminum "Backwards." Backwards my a$$. That set comes in real handy in cases like this! I first got the canards glued on, then adjusted the FGG with the other guides so that the guides were placed in the sweet spot for best guidance of the main fins. I had to have the fins relatively high so I could get clamps on 'em:

    Click image for larger version. 

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    Click image for larger version. 

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    Result: main fins and canards perfectly coplanar even accounting for the difference in fin thickness.

    Here's the finished result:
    Click image for larger version. 

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    So, to sum it up, I've got a nice system with three different sets of guides, that each work in different circumstances, and I could always make some narrower guides if I need them. I'm delighted with the new level of perfection in fin placement I can now achieve. The biggest single error factor in getting these fins on, remarkably, is in drawing the lines that I use. I can get to within about a half millimeter. I actually used all three lines, and sort of did a visual average versus the guides to get optimal placement.

    You may notice the fins are next to the guide lines, mostly. This is purposeful, so I can use the guide line to make sure my fins are true to vertical. See the Vega thread for more detail on the build.

    Last edited by Marc_G; 21st February 2012 at 03:36 AM.
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  26. #26
    Join Date
    2nd January 2012
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    Awesome job man - and a ton of perseverance! I was thinking, next time (if there's a next time) draw the alignment lines on the base plate, number each line, number each aluminum plate to match, drill your holes in the aluminum first, then set the plates down on the base plate and use them as your drilling guide on the base plate before you mount them up. That way the holes HAVE to line up!

    - E

  27. #27
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    6th June 2010
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    Quote Originally Posted by Elon View Post
    Awesome job man - and a ton of perseverance! I was thinking, next time (if there's a next time) draw the alignment lines on the base plate, number each line, number each aluminum plate to match, drill your holes in the aluminum first, then set the plates down on the base plate and use them as your drilling guide on the base plate before you mount them up. That way the holes HAVE to line up!

    - E
    I thought to do that, but since my holes in the aluminum weren't perfectly even / aligned, extending the line of holes out along the line was messy.

    It worked out pretty well with the larger holes in the guide...
    Thou shalt not violate causality within my historic light cone. Or Else.
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  28. #28
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    6th June 2010
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    I decided to whip together a Blue Bird Zero (original scale in BT-55).

    This was another practical test for the Fin Gluing Guide, as there are two sets of fins that have to be kept in alignment.

    Here are some pics:

    Click image for larger version. 

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    Yes, there's a glue gap in the above picture... I fixed it after taking the picture.

    Click image for larger version. 

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    I'm pleased to report that it worked perfectly. the fins went on at exactly the right angles and such. Hooray. Something that actualy works!
    Thou shalt not violate causality within my historic light cone. Or Else.
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  29. #29
    Join Date
    2nd January 2012
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    Sweet!

    - E

    Quote Originally Posted by Marc_G View Post
    I decided to whip together a Blue Bird Zero (original scale in BT-55).

    This was another practical test for the Fin Gluing Guide, as there are two sets of fins that have to be kept in alignment.

    Here are some pics:

    Click image for larger version. 

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    Yes, there's a glue gap in the above picture... I fixed it after taking the picture.

    Click image for larger version. 

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    I'm pleased to report that it worked perfectly. the fins went on at exactly the right angles and such. Hooray. Something that actualy works!

  30. #30
    Join Date
    5th April 2012
    Location
    Texas
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    2
    Quote Originally Posted by Marc_G View Post
    I decided to whip together a Blue Bird Zero (original scale in BT-55).

    This was another practical test for the Fin Gluing Guide, as there are two sets of fins that have to be kept in alignment.

    Here are some pics:

    Click image for larger version. 

Name:	FGG  047.jpg 
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    Yes, there's a glue gap in the above picture... I fixed it after taking the picture.

    Click image for larger version. 

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    I'm pleased to report that it worked perfectly. the fins went on at exactly the right angles and such. Hooray. Something that actualy works!
    Marc, you have done a great job in making the jig, kudos to you. Do you think a piece of peg-board would have worked out better while drilling the holes in the base-plate and in the wood plate attached to the aluminum? This question now has brought to my mind, the little there is left, but one could use the factory cut edges of the peg-board as guide line to draw for the laying out the different degrees of angle needed, 45, 90, 135, 180 and etc? right???

    I do like your design and your comments while building the jig. It was a hoot in reading and picturing oneself in the same boat, but without AFLAC in the boat with you.
    Bill


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