Rocket sled new and improved. (video)

Discussion in 'The Watering Hole' started by mbecks, Feb 19, 2018.

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  1. Feb 19, 2018 #1

    mbecks

    mbecks

    mbecks

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    I've rebuilt my rocket sled and added some IMPROVMENTS. please tell me what you think and what you want me to try or change. thanks for watching.

     
  2. Feb 19, 2018 #2

    neil_w

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    “Imporved”? ;)
     
  3. Feb 19, 2018 #3

    mbecks

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    Oh snap haha guess I’ll have to fix that.
     
  4. Feb 19, 2018 #4

    Daddyisabar

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    Everyone always wants and needs a bigger motor!
     
  5. Feb 19, 2018 #5

    neil_w

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    Well done.

    The construction looks really good, but I definitely think you should consider ways to make it lighter. That's your best avenue to getting more bang for your buck out the smaller motors. I can't quite tell what your materials are at the moment, but maybe there are some substitutions you could make to pull some weight out of it.
     
  6. Feb 19, 2018 #6

    Nytrunner

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    I like the flame thrower effect of the ejection charge from the gopro perspective.

    What are your skis, wood?
    The deck could be lightened by drilling a bunch of holes in it. If that's 1/4" plywood, you can swiss cheese it before you'll lose any strength in the thrust direction.
    Plus I'm sure you know you're suspension and hinging add some mass in there. (is that a solid metal rod on the backend?)
     
  7. Feb 19, 2018 #7

    mbecks

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    Neil_w and Nytrunner - The materials are mostly wood. Skis are from an old toboggan, 2x4 chunks for mounting blocks and 1/2 MDF for the main board. The hinge and threaded rod are both steel. the shocks are just light plastic with metal springs. I definitely got to fixated on making the shock system work and forgot to consider weight. One advantage I'm finding for the weight is its seems solid on the ground but also means I need way more thrust. I guess I could lose the metal rod and put a dowel there and have the skis at a angle and I could drill a bunch of holes to lighten it up. I'm really considering making a version 3 that is way lighter since the motors to run version 2 are getting pricey at 10 bucks a pop. I'm thinking ill do another video with staging and a big motor just to see how it handles it then revamp it. Like I say in the video I think I over engineered and should have probably stuck with the old KISS rules.
     
  8. Feb 19, 2018 #8

    Nytrunner

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    Gotcha. Found what you had and threw something together for fun. And fun has been had! Now time to optimize.

    Although, I can't help but wonder, what if you tried........Two motors.....At ONCE!
     
  9. Feb 19, 2018 #9

    dhbarr

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    If you do, stack 'em up-and-down, not side-by-side. Misfires are way less costly that way.
     
  10. Feb 19, 2018 #10

    Nytrunner

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    One on top of deck, one below! Reduce the moment your applying that'll try and nose your sled into the ground
     
  11. Feb 20, 2018 #11

    mbecks

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    Nyrunner - that is pretty much exactly what happened. I saw the RC car shocks sitting there and my old sled hanging on the wall and figured it was a good excuse to get back into the game.

    I'm 100 percent going to do some rocket stacking, It was to much speed for my old sled but I bet it will be just right for this heavy beast. Here is a clip of me trying it with my old sled. skip to 1:00 mark. Unfortunatly its supposed to be ridiculously cold for over a week here, so I probably wont be getting out for further launches anytime soon. It will give me a chance to start my rail guided sled so that's the up side.
     
  12. Feb 20, 2018 #12

    mbecks

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    Looking for some opinions here, what do you guys think of my video format, description->launch->closing thoughts. Should I change it up and if so how what do you think would improve the my videos?
     
  13. Feb 20, 2018 #13

    Nytrunner

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    Looks fine to me. Not too long, good cuts to action, and unobtrusive script overlay.


    Looking forward to the rail follower. What are you going to use, roller blade or skateboard wheels?
     
  14. Feb 20, 2018 #14

    neil_w

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    I like it overall; as Nytrunner says it's nice and concise. That said, I have a few small comments:

    1) I'd like a wee bit more background given up front; you sort of jump into it with the assumption that everyone knows your history with these things. Just a few sentences of background would be helpful. On the last video, for instance, you seem to have switched back from the updated sled with suspension to the older one, but nary a word of explanation.

    2) It wouldn't be bad to show your face on the video. Seeing a human actually talking once in a while rather than pure voiceover is a welcome change.

    3) One more camera angle for the sled runs would help. The way you're shooting it now (from behind the sled), you get a great view of the launch but then as it goes into the distance you kind of lose sight of it. See if you can set up one additional camera something like 100ft away, next to the tracks, so the sled goes towards it. You may want to experiment a bit to see what position and angle looks best. I understand this is more effort, but hey. :)

    Anyway, I'll keep watching. Fun stuff.
     
  15. Feb 21, 2018 #15

    Cabernut

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    FYI, the second video here is an old one of the old sled, he hasn't switched back.

    For rocket sled V3 I would try going much lighter and mabe use downforce instead of weight, like F1 cars do.
     
  16. Feb 21, 2018 #16

    mbecks

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    Thanks for ideas,
    nytrunner - I’m going to use roller blade wheels, I just bought a set of used roller blades yesterday. I also have a section of rail road track I’ve had for a long time that I use as an anvil but it will let me have something to build around.

    Neil_w - I like the idea of a camera out in front of the launch, I did actually have 2 other cameras out originally but the batteries froze and they wouldn’t turn on. About showing my face, I did originally shoot some of my footage with me on camera but never felt natural. I’ll have to do some trial shots and test them out on TRF. Use you guys as test subjects haha.
     
  17. Feb 24, 2018 #17

    mbecks

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    I just watched some history on the Saturn 5 and realized the significantce of the v2 rocket. This sled is not worthy of the name..
     
  18. Feb 24, 2018 #18

    dhbarr

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    Quick, watch a documentary on software versioning! :-D
     
  19. Feb 24, 2018 #19

    mbecks

    mbecks

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    Hahaha nice
     
  20. Feb 26, 2018 #20

    Knuckledragger

    Knuckledragger

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    Come on now! I've seen them use 8 solid rockets on the sled while shooting the Trident II second stage down the rails at Holloman AFB! Or if you really want to push it...
     

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