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  1. #1
    Join Date
    8th December 2005
    Posts
    131

    LOC Viper IV build

    As a member of CATO, it's becoming the "in thing" to have a Viper IV so I figured I would join in on the drag racing fun!.

    Didn't alter the kit too much, mainly changing the shock cord mount, adding motor retention and using 2 - 1 1/2" launch lugs rather then 1 - 6" lug.

    Here's the shock cord anchor. 3/16" eyebolt with 2 nuts lock tited on (see the red) and tightened against each other. The nice part about these 3/16" nuts is that they don't rotate in the cluster of 4 - 24mm tubes. Stuffed a piece of wadding into the hole and filled it with epoxy and inserted the eyebolt:




    For the motor retenion, a 1/4-20 coupler nut again fit into the cluster of MMT's and didn't rotate. Packed the wadding into the MMT gap and some into the bottom of the coupler nut to keep out the epoxy. Sanded the nut with coarse sandpaper to create ridges for the epoxy to bit into and stuck it in. Took a couple of tries to be able to get the nut in flush with the MMT without the epoxy over flowing:




    Had a bit of a scare with the fins. I was ready to bevel the fins and attaching them to the MMT and had a thought. Why don't I use the mower blade sharpener attachment on my dremal to bevel the fins!! At least the rough sanding, then I could touch them up after by hand. Well, got it all set to go, grabbed a fin and started grinding away...only to discover I was sanding the ROOT edge of the fin. AAAHHHHH. Dropped it in panic, thinking I will now have to trim all the fins to match...UNTIL I remembered that you have to bevel the root of the fins to fit in between the tubes. Duh.

    Getting ready to bevel the fins:


    Now the tricky part. How to hold a 4 motor cluster onto a base designed for one motor. The cylinder to the left is what is supposed to fit in the center hole in the fin jig. The eyebolt with the washers and nuts is what I inserted (from underneath) to screw into the motor retention nut to hold the motor tubes centered and straight. This photo was taken after they were epoxied in:


    All clamped up and curing. The 2X4's under the base plate are needed because of the eyebolt:


    Applying the fillets:


    Ultralight weight shock cord mount on the NC. Cut 2 slots for the nylon strap to fit through:


    The drying booth:


    The build is almost complete. I've epoxied the MMT to the body tube and should have finishing photos by the end of the week.

    Mike Courtemanche
    TRA 1028 L1
    NRA 85947

    Fly fast, Speed Thrills

  2. #2
    Join Date
    13th June 2006
    Posts
    92

    Thumbs up

    Very nice, My Grandpa has one of these. It flies great. wonderful on D12's and not too overwhelming on E9's. But he was too scared to fly it on composites, so I flew it for him on 2 E30's for a most excellent flight. I like your paint job as well!

    Taylor Jessee
    NAR# 76955


    On the Workbench: 54mm Minimum Diameter

    Current Fleet: 29mm Upscale Corkscrew, AT Sumo, AT Airspike, AT Initiator, PML Tiny Pterodactyl, PML Amraam 2.1, PML Amraam 3, 29mm Big Daddy, BSD Little John, Binder Design Stealth 54, Polecat 5.5" Nike Smoke :D

  3. #3
    Join Date
    25th December 2003
    Posts
    3,990
    Make sure you sign up for the Saturday AM Viperfest at NERRF.
    Al Gloer
    TRA - 10603 L2 NAR - 83142 L2
    President, CATO - CT
    WWW.CATOROCKETS.ORG
    WWW.NARCON2009.ORG

    Less than 365 days to NERRF 5

  4. #4
    Join Date
    18th January 2009
    Location
    Canton, Ohio
    Posts
    623

    Where did you get this, do you make them? That looks real handy and I'd love to have one.

  5. #5
    Join Date
    8th December 2005
    Posts
    131
    They can be found at http://www.bmibay.net/finjig.html
    Mike Courtemanche
    TRA 1028 L1
    NRA 85947

    Fly fast, Speed Thrills

  6. #6
    Join Date
    18th January 2009
    Location
    Southeastern PA
    Posts
    3,980
    Originally posted by getoutside3274
    They can be found at http://www.bmibay.net/finjig.html
    Just a question, are these worth the money? BTW, great build. Looks beautiful!
    Josh

  7. #7
    Join Date
    12th September 2009
    Posts
    677

    Thumbs up well worth the money.

    I built one of these back in '96 or so and flew it MANY times. I was more than pleased with the performance of this kit. Had a D-12 CATO on me once and it blew the nosecone right after take-off (but left the chute in the tube), the rocket hit the ground from about 60 feet up and didn't even scratch the paint. I'll try to post some pics of it when I find them.
    I'd recommend this kit to anyone who likes clusters! I'd love to see videos of that drag race if you can get any. And very nice job on your build.

    Mike

  8. #8
    Join Date
    25th December 2003
    Posts
    3,990

    Re: well worth the money.

    Originally posted by OverLord
    I'd love to see videos of that drag race if you can get any.

    Ask and ye shall receive

    CATO VIPERFEST
    Al Gloer
    TRA - 10603 L2 NAR - 83142 L2
    President, CATO - CT
    WWW.CATOROCKETS.ORG
    WWW.NARCON2009.ORG

    Less than 365 days to NERRF 5

  9. #9
    Join Date
    14th July 2009
    Posts
    167

    Re: well worth the money.

    I think he was asking "is the fin jig" worth the money, rather than the Viper...
    Nathan, Southern Maine

  10. #10
    Join Date
    8th December 2005
    Posts
    131
    Just a question, are these worth the money? BTW, great build. Looks beautiful!
    I think so. I don't like any "squirrliness" in my flights and the rockets fly arrow straight with the jig, providing other forces don't affect the flight too much.

    I think I have a pretty good eye for aligning fins (unless you count that 3" Phoneix I built about 16 years ago...I look at those fins and say "my god, what was I looking at!) but this jig allows me to get good pressure on the fin towards the MMT and clamp it there as it dries. Without the jig, attaching one fin at a time the tape is generally used to hold the fin vertical as well as apply some pressure into the MMT. Not sure if there is any really benifit to holding the extra pressure on the fin but it makes me feel good
    Mike Courtemanche
    TRA 1028 L1
    NRA 85947

    Fly fast, Speed Thrills

  11. #11
    Join Date
    28th January 2009
    Location
    Rhode Island
    Posts
    534
    Just add some lead to the bottom of it and the nose will always stay pointed up Yup eight ounces should do it hehe. Just some help from the competition lol
    NAR# 86139 L2

    If the world didn't suck we would all fall off :cool:
    Experience is something you don't get until just after you need it.

  12. #12
    Join Date
    12th September 2009
    Posts
    677

    Talking Re: Re: well worth the money.

    Originally posted by Hospital_Rocket
    Ask and ye shall receive

    CATO VIPERFEST
    Thanks HR! Very cool!

    Mike

  13. #13
    Join Date
    12th September 2009
    Posts
    677

    Re: Re: well worth the money.

    Originally posted by dasein668
    I think he was asking "is the fin jig" worth the money, rather than the Viper...

    Oppsie, your right Dasein...My bad...Although if I had an extra 130 bux I'd consider buying one...Looks like a really well made jig..

    Mike

  14. #14
    Join Date
    8th December 2005
    Posts
    131
    OK it's coming to the end. I'd have to say that my first (and second!) experience with water slide decals wasn't the best. It looks OK (from about 10' or so). I have the one Viper iv decal to put on then clear coat:


    A close of the lethal end!


    Let the games begin!
    Mike Courtemanche
    TRA 1028 L1
    NRA 85947

    Fly fast, Speed Thrills

  15. #15
    Join Date
    28th January 2009
    Location
    Rhode Island
    Posts
    534
    Nice Job, mike looks good!! That must have been fun to put on
    NAR# 86139 L2

    If the world didn't suck we would all fall off :cool:
    Experience is something you don't get until just after you need it.

  16. #16
    Join Date
    18th January 2009
    Location
    Southeastern PA
    Posts
    3,980
    That looks great! Where did you get the decals from?
    Josh

  17. #17
    Join Date
    13th June 2007
    Posts
    3
    So tell someone that has never touched off a multi-engine bird what kind of ignighters are you using?? Just curious..

    Matt

  18. #18
    Join Date
    28th January 2009
    Location
    Rhode Island
    Posts
    534
    Standard Estes igniter's, it was my first time at lighting multiple motors. I thought there was a trick, nope just take your time and it works great. You or rather I attached them in parallel with one piece of tape on each motor and used a clip whip to attach them to the two trigger wires.

    NAR# 86139 L2

    If the world didn't suck we would all fall off :cool:
    Experience is something you don't get until just after you need it.

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