Tutorial: Build an articulated hand for Bioloid scale robots

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    Slugman Slugman is offline Neuron
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    Build an articulated hand for Bioloid scale robots

    Difficulty
    About 4/10 for the mechanical side. As long as your robot is Arduino compatible or using a robot computer then it’s about 6/10 for incorporating the controller into your project, but you will need to be running your own program.
    Estimated Time
    Once you get the parts from the laser-cutter, it’s about 5-6 hours spread over two days – A lot of the time is waiting for the thread-lock to dry properly. As for the time to program it to actually work with your robot I have no idea – I haven’t finished that far yet.
    Skills Required
    Basic tool use should be sufficient, but it's fiddly. Very fiddly.
    Parts Required
    0.9 or 1.2mm Stainless steel sheet – Supplied by the laser-cutter. Cheap compared to actually getting the parts cut
    Seven E-Sky 7.5g Featherweight servos – Approx $13 each = $91
    Length of 0.91mm Spring-steel RC Aircraft control rod – Approx $2.60, & you won’t use much
    Seven Micro Ball-links – I used 4x DuBro Micro Ball-link (Cat. No.929) for 0.047” pushrod sets at $7.25 each = $29 + some spare ones I had lying around.
    Threaded pushrods that fit your Ball-links – Around $10
    41x M2 bolts with nuts – Grab some from your box of Bioloid stuff.
    Thread-locking fluid, such as Lock-tite – Approx $5 to $6
    Super-glue – Approx $5 to $6
    Servo controller – I’m using a Pololu serial servo controller for each hand - $19.95
    Voltage regulator - Assuming you are using Robotis servos then you need to supply a reduced voltage to the hand servos to suit their requirements. I'm using a Jaycar variable regulator with a home-made heat sink, but it should supply the servos of both hands with power - $19.95
    Tools Required
    Laser-cutter, or the ability to get parts cut using one – Usually achieved with lots of money
    File – Fairly fine, for cleaning up the edges of the laser cut parts
    Drill & 2mm drill bit – Drill only holds the bit tightly – Don’t plug the drill in!
    2x fine needle-nose pliers – Preferably have one with no more than a 2mm width at the end
    Flat-nosed pliers – Should have a clean & sharp end, not old & worn round
    Very thin texta or something that can write on stainless steel & be wiped clean later
    Sheet-metal bender is useful, but you can get away with just another pair of flat-nosed pliers
    Small screwdriver to fit Bioloid M2 bolts
    Spanner for the Bioloid nuts, or use the needle-nose pliers to hold the nuts stead
    Is your AX-12 Bioloid getting laughed at because it’s not cool enough?Is your wallet too full?Are you upset that your AX-12 Bioloid has too much carrying capacity with too little dexterity?Do you need a fiddly project to re-fill your swear-jar at home?....Well have I got a deal for YOU!Cost - Approx $250 per hand, depending on the price of laser-cutting, & how you control the hand.Weight - Approx 110 grams per hand including the servos if using 1.2mm stainless steel. If you modify the CAD to reduce the amount of steel you could reduce this a bit - The seven servos weigh about 53 grams on their own, but compare this to a single AX-12 at 55 grams. Hmmmm, should I have a single powerful claw or a fully articulated hand that can give someone 'The finger'?We all know that robots making rude gestures is the pinnicle of human achievement and social expression.Why have I done this, & why is it posted here for free where anyone can take it, modify it & re-create it?I made this hand as a technical exercise for my own deranged enjoyment, & because I could not find anything in the Bioloid scale that I would actually want to bolt onto my robot. The closest I found was the zip-tie backed chain fingers that Andrew made ages ago, & “xnonox” recently posted a video of his version that seems to work very well, & it’s cheap to boot! I decided to do things the hard way, & make something that everyone knows is impossible. The reason it’s freely available here is because I want to give a little something back to this community that I have been leeching info from for the last few years. If just one person in a hundred does the same, we will all be so much better off, & I hope to help facilitate that. The cost to me for supplying this tutorial is zero, as I was going to build the hand anyway. This is my hobby, not my source of income.The fact that it will lead to SkyNet & ‘Judgement Day’ is beside the point.
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Replies to Tutorial: Build an articulated hand for Bioloid scale robots
  1. Join Date
    Jul 2008
    Location
    South Sphincter Idaho
    Posts
    613

    Re: Build an articulated hand for Bioloid scale robots

    Hey Slugman,

    I was looking at the tutorial, but am unable to open the DWG file. My wife is a draftor, and worked with Acad for 20 years, but the newest version of Autocad we have is 2006. You may want to mention to folks what version of Acad will open it, or perhaps save it in a more universal format. The error I get from Acad is " The Drawing File is not Valid".

    I wasn't planning on building the hand, so I really don't need the file, but some other will need it.

    Thanks for the contribution to the community..
    Gary
    Team Maggot---Mechs. "Bheka" (retired), "Maggot Mk.3(A)"
    " Keep your stick on the ice ".... Red Green
        

  2. Join Date
    Jun 2010
    Location
    Australia
    Posts
    161

    Re: Build an articulated hand for Bioloid scale robots

    Dang!
    The program I drew it with is "DoubleCAD XT", which is a free program - I had to register on their site to download it, but it's free. I then had to teach myself how to use it, as I would have had to pay for the manual........ >:S
    The company I used to do the laser-cutting seemed to open it OK, so it might need a later version of AutoCAD, but I'm not an expert in CAD by any stretch of the imagination.

    Can your wife suggest the best format I should save it in? I don't know what's commonly used. I used the DWG format as that was what the laser company asked for.

    Thanks for the kind words - You guys that are the core of the Trossen community have helped a lot of us noobs & usually get silence in return, so it's just my way of saying thanks.
        

  3. Join Date
    Jul 2008
    Location
    South Sphincter Idaho
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    613

    Re: Build an articulated hand for Bioloid scale robots

    Hey Again,

    Just for the fun of it, I downloaded DoubleCAD XT to play with. The wife may like Autocad, but I don't get along with it very well. Her suggestion was to save the file for an earlier version of Autocad.

    I loaded the drawing up in DoubleCAD, and did a "Save as" to Autocad 2000-2003. Now I can open it in the 2006 version we have. This really may not be too important, unless there are more folks out there with old versions of Autocad. The laser cutter shops probably all have much newer versions, as business depends on keeping up with the technology. One could even save it in a few different formats just for the fun of it....

    Have Fun
    Gary


    Team Maggot---Mechs. "Bheka" (retired), "Maggot Mk.3(A)"
    " Keep your stick on the ice ".... Red Green
        

  4. Join Date
    Jun 2010
    Location
    Australia
    Posts
    161

    Re: Build an articulated hand for Bioloid scale robots

    Lol - You are a step ahead of me as usual - I found that my original file is 10-11, so I re-saved it as 00-02 & 04-06, & I'm about to replace the Zip file with one containing all of the versions, since they aren't very big.
        

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