Summary of How to Make a DIY ChalKaat CNC/Laser Cutter
Chal-Kaat is a DIY direct-manipulation laser cutter that lets users draw strokes directly on the workpiece to specify cuts. A top-mounted RGB camera tracks hand-drawn colored markers for scaling and positioning, while a pico projector projects the scanned image and toolpath onto the material. The system converts the captured image into G-code and drives stepper motors and a laser module to cut at the exact projected location, removing the need for separate CAD measurement and providing immediate, tangible feedback.
Parts used in the Chal-Kaat:
- 2W laser without driver
- Laser driver
- Laser heat sink and mount
- Build your own Arduino
- Wireless programmer for Arduino
- Pololu stepper motor drivers (2)
- Stepper motors (at least 2)
- Pico projector
- USB HD Web Camera (RGB camera)
- Stainless steel rods
- SK8 mounts (4)
- SC8UU bearings (6)
- Belts
- CPU fan for cooling laser
- Cardboard base
- Glue
- 12v 4A power supply
- 6v 3A power supply
CNC/Laser cutters are invariable tools of modern day fabrication and there are a lot of open source DIY laser cutter projects that you can make. They are now being widely used in industrial applications at a more personal and mass consumer level. But the cutters today have an indirect interface involving external computers. I can explain this better with an example. Imagine you want to cut a leather bracelet for your arm. To do this with present laser cutters, you will have to first take the measurement of your wrist, make a CAD drawing, and only can you cut a shape. There are two problems here:
- Taking measurements is a boring and tedious process.
- The user doesn’t get the actual feel of the size and place of the final cut. For example, a 1cm radius circle will look different on different screens at different zoom levels.
What if you could simplify this by placing your hand directly on the work piece and telling the system directly about measurements, using hand strokes? It removes the process of tedious measurement taking and CAD modeling. The system projects the tool path telling the user about the actual size to be cut and the actual position where cutting will happen.
Chal-Kaat(meaning lets cut in Hindi) is an attempt to do exactly this. It’s a direct manipulation DIY laser cutter that’s aware of the strokes being drawn on the workpiece. Chalkaat is a pen stroke based UI for interacting with laser cutters. The users can express themselves by working directly on the workpiece. The camera on top tracks the strokes on paper. Different colored markers allow different commands to be executed. We built a laser cutter from ground up, with computer vision and mechanics to optimize the interface.
Required Materials
- 2W laser without driver($84)
- Laser driver($36)
- Laser heat sink and mount($4)
- Build your own Arduino it’s much cheaper (less than $5)
- Wireless programmer for Arduino($22.5)
- 2 Pololu stepper motor drivers ($12)
- At least 2 Stepper motors (got them from my 3D printer)
- Pico projector($110)
- USB HD Web Camera($68)
- Stainless steel rods (got them from local market for $4)
- 4 SK8 mounts ($8)
- 6 SC8UU bearings ($20)
- Belts (got them from my 3D printer)
- CPU fan for cooling laser($5)
- Cardboard base (got them from local market for $2)
- Glue (<$1)
- 12v-4amps and 6v-3amps power supply (got them from local market for $10)
The total cost comes up to $390. You can reduce the cost of your DIY laser cutter further by salvaging components like motors, drivers, belts, bearings, and fans from old electronic gadgets.
How Does it Work?
As explained above, the ChalKaat project allows you to interact with your cutter and design your results on the work piece. This is how the system works:
- User places the object to be cut under the system or manually draws the dimensions using hand strokes.
- System scans the image, generates g-code, and projects the scanned image on the work piece.
- User can now use different colored markers(red and blue here) to translate and scale the projected image.
- After fixing the position and scale, the laser cutter will now cut out the work piece of that exact scale and position.
This is achieved using a projector and an RGB camera. The RGB camera has two functions:
- It tracks the hand strokes by scanning the image.
- It tracks the markers for scaling and positioning.
The projector, on the other hand, projects the scanned image on the material surface used for cutting.
Read More: How to Make a DIY ChalKaat CNC/Laser Cutter!
- What problem does Chal-Kaat solve?
It removes tedious measurement and CAD modeling by allowing direct stroke-based interaction on the workpiece and projecting the actual cut position and size. - How does the user specify dimensions and position?
The user draws hand strokes or places the object, then uses different colored markers to translate and scale the projected image. - What hardware tracks strokes and markers?
An RGB USB HD web camera mounted above the workpiece tracks hand strokes and colored markers. - What does the projector do in the system?
The pico projector projects the scanned image and toolpath onto the material surface for visual feedback and alignment. - How is the scanned image used to cut?
The system scans the image, generates G-code from it, and the laser cutter performs the cut at the fixed position and scale. - Can components be salvaged to reduce cost?
Yes, motors, drivers, belts, bearings, and fans can be salvaged from old electronic gadgets to lower total cost. - What are the main electronic control components?
An Arduino (built DIY), wireless programmer for Arduino, and Pololu stepper motor drivers control the system. - What cooling is used for the laser?
A CPU fan is used for cooling the laser module.
