S2 Marauder: 12-shot Semi-automatic ...



  • alexhsiaochungalexhsiaochung Posts: 4
    edited 2012-04-13 - 22:09:53
    HI PhiPi :
    Could you give me the
    CorelDraw files of the [h=2]12-shot Semi-automatic GUN[/h]
    SO, I can laser cut a copy for myself for teaching purpose

    Thanks for your help


  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-04-14 - 11:22:01
    alexhsiaochung (and anyone else who might ask),

    The design file is not yet ready to enter the wild.

  • ercoerco Posts: 19,837
    edited 2012-04-14 - 22:22:26
    Phil: Your Marauder was a big hit at Expo. Lots of interest. Rich (W9GFO) and his two sons did a great job demonstrating your cup-shooting routine!
  • Cats92Cats92 Posts: 149
    edited 2012-04-15 - 01:45:58
    Very nice project Phil.

    Hope a kit.

    I try to teach some robotics to groups of kids (10 / 12 years old) every Wednesday.

    Made robots with plastic or wood and used the known tricks with ping , ir detectors , Xbee .....

    But i have only basic equipement for cutting , drilling, milling.

    Always looking for new ideas to keep it attractive .

    What is your advice for finding :

    * pieces like escapement mechanisms for small bots

    * useful documents or books ?

    Thanks for help.

    Jean Paul
  • RebelRiderRebelRider Posts: 7
    edited 2012-04-16 - 06:28:04
    What was the laser cutter you used?
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-04-16 - 08:35:15
    I used an Epilog Zing16, their entry-level model.

  • RebelRiderRebelRider Posts: 7
    edited 2012-04-16 - 19:00:41
    I used an Epilog Zing16, their entry-level model.


    Thanks, your Marauder looks real nice.

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-04-17 - 11:01:12

    Thanks so much to you and your sons for demoing the S2 Marauder at EXPO! I found this photo among your collection:


    I hope your son was successful in knocking down the paper cups! :)

    I'm not sure where to go with the project from here. The design needs a couple tweaks; and, although there does seem to be some demand, it's probably not something that I want to kit up and sell directly. In some circumstances, I would approach Parallax with such a product. But that would entail their endorsing use of the S2's hacker port beyond a nod and a wink, i.e. "It's there, but the warranty might be voided if you open the housing." Still, I guess it never hurts to ask.

  • W9GFOW9GFO Posts: 4,005
    edited 2012-04-17 - 14:39:36
    He had a good time with the Marauder. Your directions were complete enough that he was able to do everything on his own. Once in a while a rubber band wouldn't fire very well but that may just be the nature of rubber band guns. It did draw a lot of interest. If I had a bit more time I would have put an XBee in the S2 so that it could be aimed and fired remotely.
  • Joe FishbackJoe Fishback Posts: 99
    edited 2012-04-17 - 17:34:00

    Great weapon! I made a three shot rifle some years ago and mounted on a BOE-BOT. It was much smaller and had a Lazer pointer to aim with. It is featured on the Parallax applications site under "Super BOE-BOT".


    It uses a little different exscapement and is much smaller. I have a drawing of all the parts in DXF format. If you like to swap drawings, let me know.

    Joe Fishback
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-04-17 - 17:41:51

    Wow! That's a really nice-looking unit! Very professional!

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-04-17 - 22:23:19
    W9GFO wrote:
    Once in a while a rubber band wouldn't fire very well but that may just be the nature of rubber band guns.
    I've seen this happen, and it was because I brain-f**ted and loaded a couple of the rubber bands in the wrong order. It's easy to forget that, when loading three rubber bands three at a time, always to start with the one furthest back.

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2012-05-11 - 12:05:43
    In accordance with Matt's preferences for manufacturability, I've redesigned the S2 Marauder to be made from acrylic (sorry Erco). In addition to the necessary tab-and-slot redimensioning, I've raised it by 1/2". This permits a greater maximum elevation angle, even with the S2 XBee adapter in place, and it still does not strain the rather short Naro servo cables:


    Although it's hard for a photo to capture, I've elected to use "pink" fluorescent acrylic for the body, which glows orange along the edges. The effect is almost neon in appearance under the right lighting conditions.

    The transparency of the acrylic also allowed an addition suggested by a friend: an LED to simulate a flash during firing. This turned out to be easier than I though it would be: just a servo cable with a bright white LED poked into the end and mounted in one of the internal bulkheads. The LED operates between +5V and the signal pin. I was a little leery of not including a current-limiting resistor. But a current measurement showed 36 mA when fully on, which is within spec, both for the LED and for the S2 hacker port's level converter chip.

    One more addition is to the programming: a cannon-fire sound effect. I downloaded a sound from the web (http://www.freesound.org/people/inferno/sounds/18390/), truncated it, added a faster decay envelope, and resampled it to 6 kHz (from 44.1 kHz). The resulting .wav file (attached zipped) is about 4.7kbytes long and fits handily in the S2's memory. With a 6 kHz playback rate, it could probably be streamed from upper EEPROM, in order to save hub memory. With the S2's tiny speaker, I wouldn't call the effect "percussive" exactly, and it's dominated somewhat by the sound of the escapement mechanism, but it still sounds like gunfire.

    Here's a video that shows the unit firing. The LED flash is too quick to be captured reliably, but it's visible in the second shot:


  • ercoerco Posts: 19,837
    edited 2012-05-12 - 09:56:56
    Again with the top-notch development details! :)

    Sweet. I need one of these even though it's plastic...

    I sure hope my wood-burning laser is in my pile of mail when I get home from vacation.
  • pdiefendpdiefend Posts: 27
    edited 2013-06-24 - 19:36:10

    What happened with this project? I remember seeing it last year and then it dropped off of my radar. I too have access to a laser cutter and this looks like an awesome toy that I would love to build. Any chance on getting an update?

    - (Another) Phil
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-09-12 - 21:18:05
    @Phil Pilgrim, I know this is an old thread, but do you still sell these? I would love to modify one to work on my Wild Thumper!!!
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2014-09-13 - 15:40:04

    'Truth is, not one was ever sold. Parallax did not want to kit them up, nor did I; so it never really got offf the ground beyond the Expo samples.

    I made some for my robotics class last Spring, but they lacked the motorized tilt and the LED firing special effect.

  • ercoerco Posts: 19,837
    edited 2014-09-13 - 20:04:02
    @PhiPi: Oppernockity only tunes once!
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,843
    edited 2014-09-13 - 20:29:16
    erco wrote:
    Oppernockity only tunes once!
    [sigh] Not every neat idea turns out to be a business opportunity. Kitting isn't as easy or brainless as one might imagine, and the Marauder had lots of little parts. Both Parallax and I understood the labor-intensiveness of the process and came to the same conclusion: nobody would pay what we'd have to charge to justify the time it would take to put a kit together.

  • ercoerco Posts: 19,837
    edited 2014-09-13 - 20:38:06
    I know, Phil. Too bad, you got some great interest from this thread. "Cowboy Coder" (Ted Macey, IIRC) sold a rubber band gun kit, triggered by an ultrasonic sensor, in ROBOT magazine. Not sure how successful that was, it was pricey.

    For anyone who wants to DIY one of these, this $2 wooden rubber band gun might be a good place to start. Ebay China, natch! I swear I've seen plastic versions of this in US toy stores in the past for about the same price, but I can't find one now.

  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-09-13 - 21:13:32
    justify the time it would take to put a kit together.
    That's why you farm it out to a Fulfillment House. They do all the kitting, shipping, etc. and you sit back and pull in the royalties. Many years ago I managed a video duplication shipping/receiving department that also did fulfillment. You would not believe the items we use to kit up and ship out!!!!
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