McWireCartesianBot 1 0

McWire Cartesian Bot v1.0

Overview

The design for this cartesian bot is inspired and heavily based on the initial design by Tom McGuire. He created an easy to assemble, easy to fabricate, and easy to work with cartesian robot that is suitable for integration with the RepRap project. On these pages, we will be documenting and elaborating on his initial work, as well as providing additional enhancements. It is a work in progress, and this page will be updated frequently.

Design Criteria

• Must be easy to fabricate using either print-off sticker template or laser cutting.
• Must be easy to assemble, using simple tools (screwdriver, wrench, etc.)
• Must be inexpensive, ($100-200 for all materials)
• Design must be computer-based for duplicability and open source compatibility.

Project Status

All files are located in the trunk/users/hoeken/mcwire-cartesian-bot/ directory of the RepRap subversion repository.

CAD Drawings

TODO

• Create Dremel Attachment Mount Plate.
• Create Thermoplast Extruder Mount Plate.
• Create X and Y motor mount drawings.
• Create pipe drill templates.
• Create working area mount system.

DONE

• Create initial DXF drawings of parts
• Create Base drawing.
• Create X stage drawing.
• Create Y stage drawing.
• Create Vertical Base drawing.
• Create Z Axis drawing.
• Create Bearing arm drawing.
• Create Z motor mount drawing.
• Resize X/Y/Z components to be printable on both US Letter (8.5" x 11") as well as A4 (8.3" x 11.7")
• Resize base to accomodate Y stepper motor.
• Add mounting points for minimum/home endstops
• Create "Mount Plate" interface... essentially 4 set points to use for mounting a 'plate' which can contains whatever type of toolhead you want.
• Redo z motor mount to have mounting holes on both sides. move drive over 20mm, re-layout bearing, etc.
• Fix screw placement on Z rails
• Add extra nail holes to z carriage
• Add mounting holes to vertical base for flange.
• Refactor design to use steel pipe as base.

Construction

• Determine if component specifications work: #10-24 x 3/4" screws, 3/4" x 3/4" rails, 1/4" acrylic, etc.
• Solicit feedback from RepRap community.
• Mockup design with cardboard and printouts.
• Order test run of laser cut parts.
• Assemble test run and document assembly process.
• Release files on sourceforge: DXFs as well as pre-made PDFs to print for hand-made machines.
• Order laser cut kits for the community.

Build It!

Fabricate Initial Parts

Laser Cut Acrylic

Using the CAD files, it is possible to get the parts laser cut to precise tolerances. It is relatively inexpensive, and a wide variety of places do laser cutting. [[1][Pololu Robotics] has a nice, easy process.

Once this design has been verified and tested, the RRRF will be doing a bulk purchase of laser cut acrylic parts to offer as a kit to researchers.

Printed Sticker Templates

We have intentionally restricted the size of the design to that each part can be easily printed on a full-sheet sticker, which can then be applied to whatever material you would like to make the parts out of. Using this sticker as your template, it is very easy to precisely drill each hole, cut each board to the proper length, and thereby create the required parts you need to build your machine. If you like building things, or you'd like to save money by building your own machine from scratch, then this method is for you.

Once the design is finalized, we will be providing PDF's that are formatted, and ready for printing. In the meantime, you can open the DXF's and print them directly. There are plenty of free DXF viewer programs out there.

Aluminum Rails

The aluminum rails need to have holes drilled in them in order to be mounted to the acrylic sheets. The easiest way to do this, is to use the sticker templates for the rails, and then drill them with a drill press.

Assembling the Machine

• Horizontal Base
• X Axis
• Y Axis
• Vertical Base
• Z Axis