Homemade Fin Alignment Guide Version 2

Discussion in 'Low Power Rocketry (LPR)' started by qquake2k, Mar 7, 2010.

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  1. Mar 7, 2010 #1

    qquake2k

    qquake2k

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    I made a bigger fin alignment guide for larger rockets. This one should take up to 3" body tubes no problem, maybe even 4". I made it from 2x6 redwood. I used screw hooks for the rubber bands/elastic instead of dowels, and used Brian Guzek's idea of using bolts and wing nuts.

    fin_guide_v2_1.jpg

    fin_guide_v2_2.jpg

    fin_guide_v2_3.jpg

    fin_guide_v2_4.jpg

    fin_guide_v2_5.jpg
     
  2. Mar 7, 2010 #2

    qquake2k

    qquake2k

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    Some more photos. I know the carriage bolts are way too long, but they're what I had.

    fin_guide_v2_6.jpg

    fin_guide_v2_7.jpg

    fin_guide_v2_8.jpg
     
  3. May 23, 2010 #3

    qquake2k

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    It works just fine with 4" body tubes. Here are photos of my LOC-IV and Integrator.

    LOC-IV_build29.jpg

    integrator20.jpg

    integrator22.jpg

    integrator23.jpg
     

    Attached Files:

  4. May 23, 2010 #4

    Winston

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    That is a _great_ idea and I _will_ be making one of those.

    Here's a TTW fin slot cutting alignment jig I made from 1/4" MDF and scrap wood, just glued together with Titebond. The white hooks are the screw type wall hangers. The side blocks were glued in place with a 2.56" body tube in between. This has been used with up to 4" tubing on a laser-guided compound miter saw. Rubber bands hold the tube in place.

    Fin slot jig 1a.jpg

    Fin slot jig 2a.jpg
     
  5. May 23, 2010 #5

    qquake2k

    qquake2k

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    Yeah, it's worked out great. I've used both the large and small versions several times. I can't take credit for the idea, though, but I think I did improve upon it.

    I like your slot cutting jig. I'm assuming it holds the body tube parallel to the blade, and you just plunge the blade in as far as you need, correct?
     
  6. May 24, 2010 #6

    gary7

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    Do you have a picture of this in use with the miter saw? Thanks!
     
  7. May 24, 2010 #7

    Andyd103

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    wow thats such a good idea i use something like this but 1/10th the size good idea
     
  8. Mar 6, 2014 #8

    Pyropetepete

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    Sorry too dig an old topic up but what length are good? I've a fin that's 12''
     
  9. Mar 6, 2014 #9

    Micromeister

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    Really the fin Length isn't that important as you can hang the length over the end of the fin platform. I don't know how big qqake2ks fin Platform is but my flatbed similar fin attachment jig has an 6" x7" long platform and handles body tubes to BT-101 (3.938").
    Since we clamp the fin to the platform while the glue dries Long fin hang over shouldn't be a big deal.

    Lg Fin Jig-g1_4Pic Page 1of2 11-13- 09_rework-11-05-13.jpg

    Lg Fin Jig-g2_2Pic Page 2of2 11-13- 09_rework-11-05-13.jpg
     
    Last edited: Mar 6, 2014
  10. Mar 6, 2014 #10

    enderw88

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    It isn't clear to me from the description, but it looks like there is a spacer between the two pieces of dimensional lumber that needs to the the same thickness as the fin being aligned. Am I misreading the pictures?
     
  11. Mar 6, 2014 #11

    Micromeister

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    You are absolutely correct. The Spacer automatically centers the fin on the body tube at the desired location in perfect alignment with the long axis of the body tube.
    Once you have spacers made they last a good long time. I just replaced a few of the original 2009 spacers a couple months ago. I think qqacke2k's jig uses elastic or string to hold the body in place. Mine uses leather straps held be an Aluminum bar back pressure plate secured with a couple thumbscrews.
    These jigs are a joy to use I have an all aluminum smaller one for Micro to about bt-50 size as well.

    Lg Fin Jig-d_5.625in top & StrapClamp 11-09_rework 11-05-13.jpg

    Lg Fin Jig-e_45° bevels & new Straps 11-09_Rework11-05-13.jpg

    Lg Fin Jig-f_Strapped Test w fin on table11-09_rework11-05-13.jpg

    MM Fin Alignment Jig-b7_3rd fin on T3 model (no clamp)_02-04-11.jpg
     
    Last edited: Mar 6, 2014
  12. Mar 6, 2014 #12

    JP Morgan

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    Nice job!
    Oh man, a LOC IV!

    JP
     
  13. Mar 6, 2014 #13

    qquake2k

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  14. Mar 7, 2014 #14

    Pyropetepete

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    So i got my wood @ 6X2 Redwood, have 2m of it.

    What length do i make the base?
    How much should i give for my fin?
    These spacers ever one is referring to, is this spacer to be the same thickness of the fins your fitting and is fitted between each block in the middle? Have not see it n use in any photos.

    Have ordered 1'' wide elastic as this won't mark the tubes and some 1'' screw eyes.

    Am building a 4'' dia bird with my booster section being 30'' long and the fins 12'' at the max, so what size should i do
     
  15. Mar 7, 2014 #15

    tfish

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    I made one of these jigs. check out about 3:20 in this video.



    Tony
     
  16. Mar 7, 2014 #16

    qquake2k

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    Here are some detail shots without a rocket in the way. The bottom board is 24" long, and the top board is 18" long. You can see the spacers clearly. They're just scrap pieces of the same stock I used for the fins, in this case 1/4". The spacers keep the fins centered to the body tube, and are very important. I've used the wrong thickness spacers by mistake, and it will make your fins crooked. Probably not enough to make it unstable, but definitely noticeable. As you can see, I use two 1/4" carriage bolts and wing nuts to hold the two boards together. This makes it easy to change the spacers. I keep telling myself that I'm going to make a set of nice, marked spacers, but haven't gotten around to it yet. (I'm fresh out of "round tuits"!)

    Let me know if you need clarification on anything, and/or more photos of any details.


    fin_guide1.jpg

    fin_guide2.jpg

    fin_guide3.jpg

    fin_guide4.jpg

    fin_guide5.jpg

    fin_guide6.jpg

    fin_guide7.jpg
     
  17. Mar 7, 2014 #17

    qquake2k

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    Your shop's too clean. That's just sick. :tongue:

    Seriously, nice video.
     
  18. Mar 7, 2014 #18

    tfish

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    It's only clean where you can see. Believe me.

    By the way thanks for posting this jig build thread. The jig makes it really easy to align and glue on fins. I just got done building a "modified" Estes Super Alpha (29mm, Raven and Tx) and used the jig on the fins

    Tony
     
  19. Mar 7, 2014 #19

    qquake2k

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  20. Mar 7, 2014 #20

    Pyropetepete

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    Thanks for the help everyone. Will post photos soon as it's finished.

    Cut the wood today @45*. Made the base section 24" and the top was 15". Drilled 3 holes evenly spaced @10mm and used 3 M10 coach bolts to hold sections together. 1" eye hooks and elastic on there way, might arrive tomorrow.

    Need too add some feet too the base. Just got to work out the best height, thinking 6".

    Have some 6mm MDF at work so will cut some of this too make a spacer. Plan to make one full size like the gentleman in the video with a section cut off more when fitting the fin (my build is using 6mm thick fins.

    Just need to give it a light sand to dress the cuts.


    Sent from my iPhone using Rocketry Forum
     
  21. Mar 13, 2014 #21

    Pyropetepete

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    Built mine at last. Will use it on this upscale project

    6X2 24'' and 15'' sections
    2X2 X2 for the feet
    X3 M10 140mm coach bolts
    X3 M10 wing nuts
    1'' wide elastic
    6X 1'' screw hook
    MDF spacer

    The MDF spacer is 6mm, same as the fin thickness. I've cut the end closest to the fin at an angle to allow me some extra space. Feet are wood glued on (PVA). I'm happy with it and so are the kids.

    Shown with a template fin size and 4'' od poster tube

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  22. Mar 13, 2014 #22

    ChrisAttebery

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    Very nice job Pyropetepete.

    I need to build one of these this weekend.
     
  23. Mar 13, 2014 #23

    enderw88

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    I ghetto'd one of these together using 2x4s and C-Clamps over the weekend. Works a charm. Thanks for the great idea!
     
  24. Mar 16, 2014 #24

    qquake2k

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  25. Mar 17, 2014 #25

    majordude

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    That's pretty neat! Do you have to use a specific fin thickness or with this work for any material?
     
  26. Mar 17, 2014 #26

    qquake2k

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    The center spacer has to match the thickness of the fins. I've used it with 1/8", 1/4", and now 3/8" fins.
     
  27. Mar 17, 2014 #27

    ChrisAttebery

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    Here's mine. I made it from scrap melamine board. This stuff is great for fixtures and jigs since it is really flat and generally stays that way. I originally made it so that there was able 8" between the tips of the V. Then I realized that the straps wouldn't be able to hold the tube against the jig. After I cut it down I realized the right thing to do would have been to cut slots into the legs of the V so that the straps could hold anything from BT5 and up. :facepalm:

    Oh well, it'll work fine. I might go back and dado the slots into the jig later on.

    Fin Jig 1.JPG

    Fin Jig 2.JPG
     
  28. Mar 17, 2014 #28

    Scott231

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    FYI - I would think it best to NOT put the three (or four) bolts together in a straight line (see Pyropetepete's pictures) as that can make the jig begin to rotate on the axis of the bolts. Shouldn't matter for fin alignment, but will wallow out the bolt holes that have been drilled in the main pieces.
     
  29. Mar 17, 2014 #29

    qquake2k

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    I'm not following you.
     
  30. Mar 17, 2014 #30

    qquake2k

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    That looks nice!
     

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