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Low Cost Robot Arm

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Re: Low Cost Robot Arm

#3
I printed a robotic arm for school. Unfortunately, we weren't using a high quality enough printer, so the tolerances were off and things didn't slot together well. I'd recommend people to know the precision of their printer before setting off to build this.

Re: Low Cost Robot Arm

#4
Anyone know how the accuracy of this compares to the similar-cost adamb314/ServoProject arm? [1] It utilizes a servo mod adding dual encoders to compensate for backlash and achieves accuracy of +/- 0.05mm (enough to thread a mechanical pencil lead in and out of the tip of a pencil). [2] He's been working on the project for 5 years, with significant improvements still in the last year. [3][4]

  [1]: https://github.com/adamb314/ServoProject
  [2]: https://www.youtube.com/watch?v=SioCwvR_PYY
  [3]: https://www.youtube.com/watch?v=_4mrb2T706s
  [4]: https://www.youtube.com/watch?v=Ctb4s6fqnqo

Re: Low Cost Robot Arm

#5
I've built my own GELLO setup (the setup the author based it's arm on) and it's quite neat, but as I only use it for teleoperation of an real arm, I wonder how useful this low cost arm really is? Considering limited range, probably backlash, and the limited torque

Also it doesn't seems to use springs like GELLO which was a nice add, although the 3D printed parts where the spring was mounted broke quickly.

Re: Low Cost Robot Arm

#8

Anyone know how the accuracy of this compares to the similar-cost adamb314/ServoProject arm? [1] It utilizes a servo mod adding dual encoders to compensate for backlash and achieves accuracy of +/- 0.05mm (enough to thread a mechanical pencil lead in and out of the tip of a pencil). [2] He's been working on the project for 5 years, with significant improvements still in the last year. [3][4] [1]: https://github.com/a…

it should be similar given similar construction; one of the reasons dynamixels tend to be pricey is the dual inboard encoder setup.

if price is a factor then a servo+encoders setup will always be cheaper; there are some dirt cheap encoders out there for the creative hacker. dynamixels offer a crappy value compared to DIY solutions, they're just easy to use off-the-shelf and have nice features that aid construction.. but hardly anything game changing.

Re: Low Cost Robot Arm

#9

I printed a robotic arm for school. Unfortunately, we weren't using a high quality enough printer, so the tolerances were off and things didn't slot together well. I'd recommend people to know the precision of their printer before setting off to build this.

Learning this is part of the journey imho. You don't even have to know that you have to pay attention to tolerances beforehand. You'll inevitably learn about it when building such thing.

Just always be aware that these things will never be perfect and don't get anxious because there are so many perfect looking projects on the internet. They most likely went through the same mistakes and might even have more people in the background. Just enjoy the journey

Re: Low Cost Robot Arm

#10

I printed a robotic arm for school. Unfortunately, we weren't using a high quality enough printer, so the tolerances were off and things didn't slot together well. I'd recommend people to know the precision of their printer before setting off to build this.

Alternatively, make everything just a tad out of tolerance and drill/sand/machine it to a more precise size.
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