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Rocket Launch: The Long Way Around — Parallax Forums

Rocket Launch: The Long Way Around

ercoerco Posts: 20,259
edited 2012-06-25 10:44 in General Discussion
http://www.youtube.com/user/digikey?v=msdjlaPaqD8&feature=pyv&ad=16003255169&kw=low%20power%20microcontroller

Shows how easy it can be to use: TI MSP430+wireless internet+laptop+bluetooth+hyperterminal+smartphone +servo pan+remote terminal+capacitive touch sensor

instead of the older, more complicated "light fuse, get away" sequence.

Comments

  • mindrobotsmindrobots Posts: 6,506
    edited 2012-05-31 20:45
    Rocket science isn't always rocket science.
  • sylvie369sylvie369 Posts: 1,622
    edited 2012-06-01 03:24
    Anyone who has done serious range duty will know what I mean by this:

    "Range is clear. Sky? Who knows?"
  • xanaduxanadu Posts: 3,347
    edited 2012-06-01 15:05
    All that for one little fsssssssssssssssssssst. How do they release a video with such bad audio? The second static pop and I was done with it... I shouldn't talk my videos are much worse.

    Kinda of makes me wonder though, all of these electronic products combined with the majority of this forum, why aren't people here pumping out things like rocket launchers to consumers on a regular basis?
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-06-01 15:53
    I lost count. How many microprocessors does it take to launch a rocket?
  • ercoerco Posts: 20,259
    edited 2012-06-01 16:36
    Duane Degn wrote: »
    I lost count. How many microprocessors does it take to launch a rocket?

    IIRC during the manned space shots there are a dozen or more computers and most of them have to be happy and "in agreement" or the countdown aborts. This system seems almost as complicated.

    If I were them, I'd worry less about launch and more about optimizing parachute deployment. That rocket fell a long way from peak altitude (like close to the ground) before the 'chute popped!
  • sylvie369sylvie369 Posts: 1,622
    edited 2012-06-04 06:52
    Among rocketeers there are a lot of folks building DIY launch controllers. We had a nice launch on Saturday morning, and I saw three DIY controllers and three commercial ones. There's quite a variety of commercial systems, as you can see here:

    http://www.pratthobbies.com/products.asp?cat=9

    My club uses a fancy system designed here in the region, and if I can ever remember the name, I'll post a link to it. (dang) Oh, yes, here it is:

    http://www.wilsonfx.com/

    For individuals, there are plenty of good and fairly inexpensive systems out there - just add a good 12V battery and you're in business. But people still like building their own, and I've seen a nice variety of wireless controllers (RF link to a relay box/battery at the pad) that are much nicer than any of the commercial controllers. Big advantage of wireless: we often have Scout or 4H groups at our launches, and they LOVE to trip over wires while looking up in the sky at rockets.
  • ajwardajward Posts: 1,130
    edited 2012-06-23 09:04
    erco wrote: »
    IIRC during the manned space shots there are a dozen or more computers and most of them have to be happy and "in agreement" or the countdown aborts. This system seems almost as complicated.

    If I were them, I'd worry less about launch and more about optimizing parachute deployment. That rocket fell a long way from peak altitude (like close to the ground) before the 'chute popped!

    They probably didn't want the rocket stuck in a tree a mile away. <- Been there, done that!!!!

    @
  • GadgetmanGadgetman Posts: 2,436
    edited 2012-06-23 09:55
    sylvie369 wrote: »
    For individuals, there are plenty of good and fairly inexpensive systems out there - just add a good 12V battery and you're in business. But people still like building their own, and I've seen a nice variety of wireless controllers (RF link to a relay box/battery at the pad) that are much nicer than any of the commercial controllers. Big advantage of wireless: we often have Scout or 4H groups at our launches, and they LOVE to trip over wires while looking up in the sky at rockets.

    How safe is it to use RF systems?
    Isn't there a danger that another transmitter can set off one of more rockets accidentally?

    Also, shouldn't the area between firing control and launch site be off-limits for anyone who doesn't have work to do there?

    Back when I was more active in RF planes(gliders, though I sometimes visited the 'airstrip' they used for powered planes, too) they had a sign warning that 'non-approved transmitters would be seized and destroyed'.
    They even had a bucket with the remains of a couple of 'toy' Walkie Talkies next to the sign.
    (Most kids' toys use 27MHz it seems)

    Back then my kit was a 27MHz AM Sanwa transmitter/receiver set and a 2metre Carl Goldberg Gentle Lady slope soarer. If a 'walkie talkie' had caused it to go out of control, it could easily have punched through the windscreen of a car, or make a mess of someone's chest...
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-06-23 11:04
    YEAH, double key lock outs and covered safety toggle switches. That is the kind of hardware that makes people think you are doing something very serious.

    Without the lock outs, I certainly wouldn't consider a RF launch.

    I really have been looking for toggle switch covers, but I want the RED ones. Yellow just doesn't seem quite right.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-06-23 11:36
    Loopy Byteloose wrote: »
    Without the lock outs, I certainly wouldn't consider a RF launch.

    I really have been looking for toggle switch covers, but I want the RED ones.

    SparkFun has some red covers.

    I'd hope they were using some sort of code for the RF launch. Many RF transceivers (XBee and Nordic) have several layers of checks to make sure a message received was really intended that particular unit.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-06-25 09:37
    Thanks, this is a real classic goodie that all DIYers would love to have. And if you want to make a movie prop, that RED is important. What madman would bother with yellow?
  • ercoerco Posts: 20,259
    edited 2012-06-25 10:04
    Several launch switch alternatives are available, such as these mercury and ball tilt switches.

    Significantly less safe, but much cheaper (just $5 for 10 units)! :):):)

    http://www.ebay.com/itm/10pcs-Metal-Ball-Tilt-Shaking-Position-Switches-/300629315805?pt=LH_DefaultDomain_0&hash=item45fee750dd

    http://www.ebay.com/itm/10-Mercury-Tilt-Switch-Low-Voltage-101-20V-0-3A-2-SHIPPING-ALL-QTY-/350576918470?pt=US_Single_Use_Batteries&hash=item51a0033fc6
  • xanaduxanadu Posts: 3,347
    edited 2012-06-25 10:14
    Duane Degn wrote: »
    SparkFun has some red covers.

    I'd hope they were using some sort of code for the RF launch. Many RF transceivers (XBee and Nordic) have several layers of checks to make sure a message received was really intended that particular unit.

    Duane, I got this red toggle switch at AutoZone, they have a bunch of different colors for $9.99 ea. More than you'd pay online but instant gratification and decent switches.

    IMG_0925.JPG
    IMG_0925.JPG
    816 x 612 - 236K
  • Dave HeinDave Hein Posts: 6,347
    edited 2012-06-25 10:44
    Even the most simple launch controllers normally use a "key", or at least an arming switch to enable the controller. There is usually an audible alarm to let you know the pad is enabled. RF controllers usually use a digital key sequence that must be received to activate the launcher, similar to a garage door opener or a wireless lock on a car door. RF controllers also use a manual key-switch to arm the pad.

    Here's a video where you can hear the arming tone prior to the launch -- http://www.youtube.com/watch?v=DFoH5A9dOqE .

    Launch controllers can fail where the relay get's stuck in the closed position because the contacts get welded together. It is always good practice to touch the controller's igniter leads together first to see if there is a spark. There have been several cases where someone hooked up active leads to the igniter, and the rocket took off immediately while the person was still at the pad. Fortunately, no one was injured in any of these cases, as far as I know.
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