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My Robot Base gets fenders — Parallax Forums

My Robot Base gets fenders

Matt GillilandMatt Gilliland Posts: 1,406
edited 2011-04-24 16:20 in Robotics
They're delrin, and the top is cast acrylic (drillable and tapable). The center piece of the top can be removed for easy access to the electronics, without having to remove all the perimeter screws.

100_4419.jpg


-Matt
1024 x 768 - 65K
1024 x 768 - 79K

Comments

  • ercoerco Posts: 20,256
    edited 2011-04-19 08:57
    Sweet! That should slow down any would-be PING thieves...

    What are those 2 semicircular thick wire rails on top? 10 kV more theft deterrent?

    Remind me to upload a pic of the padded denim coveralls I made to protect my Hero Jr robot.
  • SeariderSearider Posts: 290
    edited 2011-04-19 18:26
    I wonder if you attach a vibra tab to the fender, could you detect collisions without false alarms? that would be great for an emergency shutdown on collision.
  • WhitWhit Posts: 4,191
    edited 2011-04-19 19:10
    Looks great Matt! Looks like it has some cool lighting too.
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2011-04-19 19:25
    The acrylic top is laser cut cast acrylic. By removing only the six screws (in the black standoffs) the center section is easily removed and the electronics under it are accessible.

    Yeah, there was cool lighting - until I let the smoke out on "Robot Day" (last Friday). Those are the Pllx ccfl's - they're really inexpensive and we figured a way to make them "grow" from one end to the other as the speed of the robot increased.

    Searider - I've actually never used one - I might try that :-)

    -Matt
  • Tony B.Tony B. Posts: 356
    edited 2011-04-20 05:49
    I'd have to say it looks really good!

    It's a little hard to replicate clear acrylic in wood. :smile:

    Do you have any video of it running? Sorry if I've missed it.

    Tony
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2011-04-20 09:14
    Am I the only one to feel sorry for the Boe-Bot in the left of the picture? It looks so ... small. It's even an older serial version, which has to be an embarrassment for it. Should you ever notice any loose screws on the big bot that you're sure weren't there before, you know who to interrogate.

    Your acrylic sheet as a static dissipative coating, right. Right??

    >It's a little hard to replicate clear acrylic in wood.

    But there is transparent aluminum. I saw it once in a Star Trek movie.
  • ercoerco Posts: 20,256
    edited 2011-04-20 09:44
    Silly rhetorical question:

    The bot already has 300 bucks worth of PING sensor collision avoidance. Are the fenders now simply protecting the PINGs? It almost implies a lack of confidence! :)
  • WhitWhit Posts: 4,191
    edited 2011-04-20 09:50
    >It's a little hard to replicate clear acrylic in wood.

    But there is transparent aluminum. I saw it once in a Star Trek movie.

    Yes, Mr. McComb, The information is here -
    http://memory-alpha.org/wiki/Transparent_aluminum

    We have to wait a few years though...
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2011-04-20 20:58
    erco wrote: »
    Silly rhetorical question:

    The bot already has 300 bucks worth of PING sensor collision avoidance. Are the fenders now simply protecting the PINGs? It almost implies a lack of confidence! :)

    In-the-box thinking there, Erco! The PINGs are there to find things to bash into. The fenders are there to keep the damage to a minimum. (Ankles not included.)
  • ercoerco Posts: 20,256
    edited 2011-04-20 22:53
    Even though Gordon schooled me thoroughly (normally a FAIL) with his witty and thoughtful reply, I'll claim a WIN by luring him out of the lurking shadows and into the limelight. If nothing else, my unwitting position as a foil provides fuel and fodder for far more intelligent Forumites to strut their stuff!
  • SeariderSearider Posts: 290
    edited 2011-04-21 07:53
    Erco,

    I am a strong believer is backup safety systems. I have a similar bot in that it uses Ping sensors, prop and Parallax motors, wheels, and driver kit. I use the Ping Sensors for navigation. Their goal is to avoid bumping into things while moving. Because these are under program control, a SW failure could render them ineffective. While a vibra tab will not eliminate the Prop and therefore software failure mode, it is still a second opinion. On my system I have several "Bump" switches around the perimeter of the Bot that are directly connected to a power relay that will remove power to the motors if pushed(bumped)

    anyway, doesn't the most gagets on a bot Win ?
  • ercoerco Posts: 20,256
    edited 2011-04-21 08:20
    Searider: I'm a strong proponent of bump switches in addition to being a peanut-gallery heckler; Matt & I openly exchange barbs within these hallowed Forum walls. Specifically, I have often kidded Matt about his 10-pack o' PINGs for his lovely plastic robot chassis and how he's artificially manipulating PING supply, demand, & stock value. :) But all kidding aside, no sensor (IR or ultrasonic) is perfect and of course it's wise to protect your investment with something like Matt's fenders. Another method would be to simply mount the PINGs without brackets in chassis cutouts and keep 'em protected by the base perimeter itself, as my hideous sketch shows. Gordon makes an excellent point in that programmed autonomous robot behavior encourages the bot to forage around on its own, and quite likely to regularly discover obstacles that the sensors can't detect.

    Just the other day I PM'ed Matt that bump switches would be worthy additions to his fenders. Thanks for seconding the motion, Michael, and yes, gadgets always WIN!
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2011-04-21 10:35
    'Course I was just trying to be funny about the bashing part, and I know in Erco's day job he has to think of ALL the out-of-the-box uses for his products.

    My robots tend to bash no matter how many proximity sensors I put on them. I figure if it doesn't leave behind the odd nut and bolt here and there ("Look sir, droids!") it's not a real robot.

    Searider mentioned Kynar film tabs. I've found these work well, and can be taped to a length of flexible plastic (like the stuff for school report covers) to increase the surface area for the flex when the plastic is in a bow shape. These could be attached slightly outside the fenders. The FlexiForce sensors are quite good for this, too, though I haven't yet used them as much.

    The 10 PINGs do look a bit crazy, but actually most of the good research bots (like the Pioneer) have something very much like it (Pioneer has 8 of the Polaroid-style transducers). This Parallax base is a lot less money. I'm quite impressed with it -- even with **BLACK** HDPE!!! (hehe)
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2011-04-21 21:14
    Hi all.
    @TonyB - Thanks! and you're right - transparent plywood isn't feasible at this time. And no video yet - soon, though, I hope...

    @GordonMcComb - to paraphrase Mr. Spock: sometimes "the needs of the large, outweigh the needs of the small" (or something like that). Don't feel too bad for the little fella though, he's gonna get a lot of roboty-back rides, once his older brother is up and running.

    Anti-stat coating for sure, and cast so that it's machinable :-)

    @searider -
    anyway, doesn't the most gagets on a bot Win ?
    Absolutely! Different types of redundancy are necessary to get around in the real-world - collectively we're building "Denser alloy. My father gave it to me." Sonny.

    @erco - Ping futures are up!

    Any and all comments, and criticisms are welcome - you know, "iron sharpens iron", or plastic, or something like that...
    -Matt
  • WhitWhit Posts: 4,191
    edited 2011-04-22 18:23
    Any and all comments, and criticisms are welcome - you know, "iron sharpens iron", or plastic, or something like that...

    What about plywood?
  • ercoerco Posts: 20,256
    edited 2011-04-22 18:38
    Like the old kid's game "Rock, Plastic, Plywood":

    Rock Breaks Plastic
    Plastic Yields to Plywood
    Plywood covers Rock

    Any more questions?
  • Tony B.Tony B. Posts: 356
    edited 2011-04-22 19:13
    A young girl, with a wooden eye, asks a shy, young man with a wooden peg leg; "Would you like to dance?" To which the young man replied, "Would I!" To which the insulted girl replied, "Peg leg. Peg Leg" and leaves. :lol:

    I don't think that joke wood work with plastic.

    Tony
  • TtailspinTtailspin Posts: 1,326
    edited 2011-04-23 05:38
    The Plastic Fenders are ok and all...
    But, Just in case someone thought it was not already done with Plywood.
    3-ply_Maple_Banjo_Rim.jpg

    An 11" X 3" three ply Maple "Ping Protection System", otherwise known as a Banjo Ring... :smile:

    -Tommy
    185 x 139 - 4K
  • RITESH KAKKARRITESH KAKKAR Posts: 254
    edited 2011-04-23 10:03
    nice work...........
  • ajwardajward Posts: 1,130
    edited 2011-04-23 13:27
    They're delrin, and the top is cast acrylic (drillable and tapable). The center piece of the top can be removed for easy access to the electronics, without having to remove all the perimeter screws.

    100_4419.jpg


    -Matt

    Sweet Matt! Looks as though it should be scurrying about the Death Star. ;-)

    Amanda
  • ercoerco Posts: 20,256
    edited 2011-04-23 20:23
    @Tommy Tailspin: You got my back, Dawg! Nice plywood banjo ring!

    Cellulite: Bad
    Cellulose: Good
    Celluloid: Best (burns great!)
  • CrazyrabbitCrazyrabbit Posts: 116
    edited 2011-04-24 07:31
    Excellent design. Looks expensive.
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2011-04-24 16:20
    Hi all-
    There are those that think a set of bumpers and hardware should become a real product and there are others that think we wouldn't sell enough to make it worthwhile.

    They were originally designed with my two boys (ages 10 and 14), because I thought it would be a good introduction and learning experience for robot hardware design. My boys got to experience the agony of mistakes, and the thrill of getting-it-right. They got to help create the precision cut file for the Laser, and then they helped me put the guards on our Robot Base - all in all - a great learning experience.

    They do provide a lot of protection for the pings - not the least of which, they prevent you from picking up the whole robot by grabbing a single ping (looks and acts like a "T" handle).

    Another thought was that my boys (like most their age) really think of a robot as something like an R2D2. So we thought that by building "additional levels" over time we could create something similar to R2, yet in slower, less expensive steps/phases.

    Several interesting suggestions have come up too: for example, make the ping openings "knockouts" so that you can selectively place pings only where you want them, and not have holes where there's no ping - or you can add more pings later, and simply knock-out the openings.

    I don't know...you'all are the real experts - any thoughts?
    -Matt
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