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Poor Man's One-Servo Gripper Arm — Parallax Forums

Poor Man's One-Servo Gripper Arm

ercoerco Posts: 20,013
edited 2020-04-03 00:28 in Robotics
My first guilty pleasure project of the shutdown, actually since Christmas. erco's been busy!

Ken CNC'ed a gorgeous gripper like this a while back, asking who'd be interested. I commented at the time that it was beautiful but not unlike these $4 Ebay grippers:

I've had a pile of these forever and finally had an hour to slam something together today. VERY rough, but you can probably see the potential. It's all just foam taped to an S3 and for its first test here, mindlessly oscillated by a servo tester. Why is it at the back, you ask? Because of the tailwheel, it would tip forward at the front.

Hopefully I get more time to play with this soon, but that's all for today. Life & real work beckon!

3264 x 2448 - 2M


  • Beautylishish!
  • Impressive. It needs more Lego.
  • ercoerco Posts: 20,013
    S3 is large & in charge.

  • erco wrote: »
    S3 is large & in charge.

    Watching that S3 at work is really therapeutic!

    Reminds me of watching snooker tournaments on TV, whilst nursing a cold or a hangover!
  • Cluso99Cluso99 Posts: 17,973
    WOW. Simple and effective :)
  • Nice!
  • WhitWhit Posts: 4,183
    edited 2020-04-03 17:08
    Excellent work, sir erco - straight to my blog!

    Can the Tower of Hanoi be far behind?
  • ercoerco Posts: 20,013
    Glad you fellas like this stuff.

  • I LOVE the modification, solution and the cost.

    But educators should be aware of the Chinese imports. They will not be able to buy the same product year-after-year because it is likely a copied commodity type of item with multiple sources. Further, there is no such thing as "free shipping". It's free to the consumer because of the e-Packet rate negotiated in the 80s, which allowed free delivery by the USPS from certain international countries in "tier three" which included China at the time. The problem is that you, the taxpayer, subsidizes the free delivery because the USPS loses billions of dollars a year bringing "free" packages into the USA. I guess you could say you're going to pay anyway, in the form of taxes.

    Again, I think this gripper and the project is awesome, for most users - but not teachers.

    The other day I was talking to a community college instructor who insisted on a DIY approach to their own Propeller-based robot, using our BlocklyProp system (like an ActivityBot 360). This is entirely possible, but at the end of the day - after spending lots of times cobbling together the parts - he saved about 50%. Then he produced a pile of HC-SR04s from various sources and asked me to support them in BlocklyProp. I have supported tens of thousands of educators in the last 25 years, but we can't help people who buy this stuff from other sources.

    So, while this is neat, hold out for the real deal. We're only a few weeks out.

    Next, erco! What's next?

    Ken Gracey
  • ercoerco Posts: 20,013
    Ken, we definitely need to collaborate on a project for schools. We should OWN robotics, period!
  • I would buy a gripper like that one. I would also like to 3D Print one as well. But I don't like buying from ebay.

  • ercoerco Posts: 20,013
    Screenshot of simple BlocklyProp code for that third video attached.
    700 x 600 - 85K
  • ercoerco Posts: 20,013
    By popular demand: Towers of Hanoi!

    Slightly modified version of the game, no posts. This simple claw design requires a fixed pickup/release height, so I had to use very flat disks with nesting handles.This video was actually the very first attempt, and it worked!

  • ercoerco Posts: 20,013
    Tom had me at "Disintegration". Youtube-suggested video has nothing to do with claws, robots, or Tower of Hanoi. But is nifty anyway.

  • If I'm going to do some retail therapy, I can't decide. S3 or P2? HELP (lol).
  • ercoerco Posts: 20,013
    BOTH !!!

    Howzit, Jon? Are you still bicoastal?
  • xanaduxanadu Posts: 3,339
    edited 2020-04-11 00:53
    At this rate it will be both: P2 + S3 = PS5 : )

    Yes, right coast for the summer. Left coast for the winter. Hope all is well by you. I've been hearing mixed reports from SoCal. Sounds like things are under control more than other places.
  • Nice looking gripper and mounting to the S3.
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