Sixi

From RepRap
Jump to: navigation, search
Crystal Clear action run.png
Sixi

Release status: Experimental

Sixi 2 Master Assembly (02-2019).png
Description
Robotic Arm
License
CC-by-SA
Author
Contributors
Based-on
Categories
CAD Models
External Link


Reasoning

If the robots take all the jobs, only the robot owners will have power. In order to ensure democracy, the robots must be owned by the people. Open source robots are a must. The most important robot I can make is a helping hand. I aim to make Marginally Clever Robots, Ltd. into the Prusa of robot arms. We will make an arm so good it can build its siblings (aka 'eat your own dog food').

Goal

The technical goal of Sixi v2 is an industrial arm you can build at home. We will make it so good it can assemble its sisters. It features:

  • Almost entirely 3D printed
  • 6 degrees of freedom, like a modern industrial arm
  • Can carry 2kg
  • Reach 80cm
  • Speed 50 degree/s
  • Accuracy goal +/-0.5mm
  • Open hardware
  • Open source

Spin-off projects include:

  • advanced gearboxes
  • automatic tool changer
  • custom end tooling
  • control software
  • advanced encoders

My plan is for three levels of kit:

  • just the non-printed parts
  • all the parts, unassembled
  • fully assembled

Technical Details

The Sixi robot uses steppers motors and two-stage cycloid gearboxes for power. They measure approximately 55% efficiency.

There are magnetic on-axis sensors for feedback. The robot always knows where it is without having to home to a limit switch. It might also one day be possible to detect collisions for human-safe collaborative work.

The firmware is inspired by Marlin and understands gcode to directly drive each motor.

The control software is Robot Overlord [1], which displays a 3D model of the arm and calculates Inverse Kinematics. Thus the programmer only needs to use a common video game controller in a Drive-To-Teach system.

D-H table

See https://en.wikipedia.org/wiki/Denavit%E2%80%93Hartenberg_parameters

Joint D Theta R Alpha
0 13.4400 0.0000 0.0000 0.0000
1 0.0000 90.0000 0.0000 0.0000
2 44.5500 0.0000 0.0000 0.0000
3 4.7201 0.0000 0.0000 90.0000
4 28.8050 0.0000 0.0000 0.0000
5 11.8000 0.0000 0.0000 0.0000
6 3.9527 0.0000 0.0000 0.0000

Workspace

SixiWorkspaceXY.jpg

SixiWorkspaceXZ.jpg

Links and More

Please see the Github repository [2] for links to the model files, software, and firmware.