Rebuild Maxi Alpha 3

Discussion in 'The Watering Hole' started by Wayco, May 13, 2012.

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  1. May 13, 2012 #1

    Wayco

    Wayco

    Wayco

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    just got back from the SSS May launch and we have some work to do. I'm starting this thread on the Maxi Alpha 3 after we had a less than successful flight where the E18-7 never came up to pressure, the rocket wallowed off the pad and ended up like this:
    [​IMG]

    After checking out the damage, it looks like the fin can is intact (amazingly enough) but we destroyed the upper body tube and nose cone. I think the BT is BT-80 and we found a similar N/C on the Apogee website that fits the BT-80 tube. Is there a site that lists the spec's on Estes kits, like how long the nosecone is or something like that?
    We have stripped the upper BT off the coupler, which I made into a cold air baffle, and here is where we are now:
    [​IMG]
    So the other questions that I have are:
    1. Where can I get a replacement nosecone?
    2. Where is the best place to buy replacement body tube?

    I'm going to be doing several projects like this, we had quite a bit of carnage at this last launch. Good thing our season is over until September.....
     
  2. May 14, 2012 #2

    samba

    samba

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    semroc.
     
  3. May 14, 2012 #3

    new2hpr

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    Balsa Machining Service
     
  4. May 14, 2012 #4

    bradycros

    bradycros

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    I can't see any major damage to the nose cone in the picture you posted. Why not just repair the the cone?

    A piece of plastic from something like a 'for sale' sign from lowes, epoxy, bondo filler and sand paper could make it good as new.
     
  5. May 15, 2012 #5

    Wayco

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    The side that is shown in the picture is the GOOD side. I was just looking at it and there are three big cracks. One is vertically up and about five inches long and another spiders out the bottom around the anchor point. I have been doing some research and Estes calls it the PNC-80K. Semroc has balsa N/C's that are similar, but I want a plastic one as similar as I can get it. Balsa Machining has a PNC-80KH that fits their Heavy tubing, but that tubing won't fit over the original coupler/baffle shown in my first post. I can get the thinner BT-80 (T-80-34) from BMS, but they don't list a plastic N/C that will fit it. Apogee has a N/C that fits BT-80 and looks similar to the busted one we have, and I will probably end up getting it unless someone here knows where I can find a PNC-80K that matches the Estes kit.
     
  6. May 15, 2012 #6

    El Cheapo

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    Wayne, brush the cracks with some plasti-struct or other plastic welding compound, sand it sown, primer, paint and call it good. I use whatever its called in the orange labeled bottle.
     
  7. May 15, 2012 #7

    paul.nortness

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    Hey, contact me....I might have a spare PNC-80K
     
  8. May 15, 2012 #8

    bradycros

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    This is an oppertunity to advance your construction/repair skills. Anyone can pull out their wallet and buy a new cone.

    Cutting off the bottom of the shoulder will give you access to the interior of the nose cone. Sand scratches on the inside area where repair is going to take place. These scratches will promote the adhesion of the epoxy.

    Plastruct, a general purpose plastic solvent cement will melt the two sides of the crack together, but future flex and stress will just crack the cone in the same place.

    Various thicknesses of plastic sheets are available at www.hobbylinc.com/htm/pls/pls91105.htm

    Cut off a piece of the plastic sheet that will fit over the crack. Sand scratches into both sides of the repair pieace. I would even go so far as to drill small holes in the repair piece so the epoxy would ooz up through the holes and then form a mushroom top. This will really lock the repair piece into place.

    A new bulkhead and shock cord attachment point will have to be constructed, but these will be alot better the what Estes made.

    A BNC-80K, 8.2" Ogive is also avalable from Semroc for $19.35, shipping is included in that price.

    I think the Sandman has the whole kit available for something like 17 buck. Certainly worth looking into.

    bnc-80k.jpg
     
  9. May 15, 2012 #9

    qquake2k

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    I've bought several of these cones from Performance Hobbies at a great price. They're listed as not in stock right now, but you could email Ken to see if he'll be getting more.

    miss_fortune18.jpg

    miss_fortune73.jpg

    miss_fortune136.jpg
     
  10. May 15, 2012 #10

    AfterBurners

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    You can check Mercury Engineering. They sell nose cones.
     
  11. May 15, 2012 #11

    qquake2k

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  12. May 15, 2012 #12

    Wayco

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    Thanks for all the great input guys! Here is where we stand right now. I'm getting a bottle of plastiweld and a thin sheet of styrene from Hobbylinc and see how it works on the broken N/C. I'm also working a deal with Paul Nortness (see above) on a PNC-80K that he has. Next week I plan on making an order with BMS for some tubing I need for this and other projects and repairs, and depending on the status of the N/C, I will determine what else I need.
    When I opened this thread a couple of days ago, it didn't look like it was going anywhere, but with all the current input, I have a good plan on what I need to do now. Thanks again for all the help, I will keep you all updated as things progress.
     
  13. May 17, 2012 #13

    KenRico

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    Think those out of stock are like these that I see on eBay :

    http://www.ebay.com/itm/Model-Rocket-Nose-Cone-2-6-Diam-BT-80-Phoenix-V2-NEW-/400297816423?pt=LH_DefaultDomain_0&hash=item5d339bf167#ht_500wt_912

    Previous listing the Buy It Now price was $8.25+$3.95 freight - maybe eMail him and see if he has some flexibility ??

    Kenny
     
  14. May 25, 2012 #14

    Wayco

    Wayco

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    Here is the latest update on this rocket repair. I bought a bottle of Plastruct Weldene at the local Hobby Bench and welded the cracks shut on the old N/C. It came out OK so I sprayed some primer on it today and touched up the cracks with some spot putty. If it cracks again, I will open it up and add styrene internally. I bought a thin sheet of it when I got the Weldene. I also got a new N/C from Paul today, but Sharon decided that I need to scratch build her an Executioner to replace the kit she gave me to build last month... :eyeroll: Made an order for body tubes with BMS and it's here already too. Once I get some white paint on this Maxi, I will finish it up as a zipperless deploy. The old N/C is pinned onto the upper BT, with the old recovery gear tied back on to the coupler/baffle.
    I did try to chase down another PNC-80K through Ken at Performance hobbies, but he no longer carries it. He did give me a link to the-launch-pad.com which is a new website for me. They sell a similar N/C, but since I got an exact copy of the original from Paul here on TRF, I think I will just work with what I have. Of course, if anyone else has another one of these, or finds a deal on ebay similar to the one posted, please let me know.
    This rocket has been kinda slap-dash from the start, especially since fins were falling off it before it ever flew, so I'm not planning on a really slick paint job, just gonna get it back up and fly it.
     

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