Intro
This weeks objective is to make a machine, for this week I wanted to make a custom cable robot using cheap components. As this will be an individual project and cable robots are fairly simpler that other machines.
The idea for a cable robot is to “hang” the body from two cables, that are tighten or loosen by two motors providing 2 dimensional movement.
Objectives
- Make a cable xy plotter
- Use GRBL or Similar
- For now draw a square
- 3D printed parts
- Rumba Control Board
- Steel Ball chain
- 2 x 608 Bearings
- M3 Bolts, spacers and nuts (multiple sizes)
- Computer power supply (12v)
- Open builds beam to mount brackets
- Drop in nuts to mount on the beam
- 2 stepper motors nema 17 with cables.
- (pronterface)[https://www.pronterface.com/] for initial communication and moving
total cost < $100
Process
I am using a previous project as reference, I modified the gears to fit the metal ball chains, and redid the motor brackets to make it nicer (concealed). Then I initially got it working with an old Rumba board (circa 2014) that i had from an old 3D printer. I reconfigured the repetier firmware (it has a cable robot setting) to adjust my stepping distances, board and mainly tried to delete everything that is not necessary.
Now i printed the parts:
And assembled the machine:
After connecting everything is time to test with the printrun interface:
Now its time for calibration:
After getting the right values we can send the following gcode to set the machine specs :
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| M4 X E S P
X is machine width
E is pen Width
S is steps per rev
P is mm per Rev
|
….
Here are some pictures of the machine :
Conclusion
Cable robots are a good alternative for large format processes. A future project could be to use the same pulleys to drive a three dimensional cable robot. Also to use an esp3d based robot to minimize the need of cables. There is a Fluid NC grbl compatible module that looks promising:
Files