DIY CNC Router

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Revision as of 22:47, 7 September 2009 by Traylerphi (talk | contribs) (Parts)
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Overview

Make something similar to MakerBot but leaning more toward the 2D / routing / cutting aspect. Something that could concievably be distributed as a "kit" with open-source design, off-the-shelf or lasercuttable/makerbottable parts.

Project Members

Design of a CNC

Frame

I think it would be smart to try to design a frame that can be created using the CNC itself, so that it is self-replicating. DaveMenninger 15:32, 3 September 2009 (UTC)
Just like the RepRap, I think this should be a primary design goal, but I'll consider the first one a success if it can carve balsa wood :) --Cjdavis 21:27, 7 September 2009 (UTC)
What size cutting area are we looking to have? TP
I think I would shoot for 8.5x11 as a minimum. Hopefully more like 10x14 or 11x17 would be doable. The bigger, the better, IMO. DaveMenninger 18:35, 6 September 2009 (UTC)
We should base the design on t-slot aluminum extrusions.
  • There are a number of suppliers of them, many of which are compatible with each other.
  • If we handle the design correctly, simple steel box tubing could easily be used in place of the extrusions, which is available pretty cheaply anywhere in the world.
  • There are even linear motion parts for use with them that could remove a lot of design effort to start with - see ( http://8020.net/Application-106.htm ) from this page ( http://8020.net/Solution-8.asp ). However, I think this is probably too specialized a part to use in a long term design. We should at least have an alternative for people using box tubing for example.

Electronics

Motors

Controller

  • something arduino-based seems like it would be a good idea

Software

Toolheads

Should be swapable as quickly as possible. The Makerbot is pretty cool in that you can just disconnect a single cable and pull the entire extruder platform out (is that possible, or do you have to unscrew the extruder head first?) Wait, is that true? Can we just mount a tool holder where the extruder goes in the Makerbot?

Possible toolheads:

  • Ink pen
  • Rotary cutter (Dremel or router motor)
  • RepRap extruder
  • Laser cutter
  • Vinyl / paper cutter
  • Paint air gun

Parts

  • Step Motors: I have four (4) AMCI SMD23 motors (the 240 model) and am very interested in working on something like this --TP.
    • IF we decide to use these motors, they have step drivers built-in. Once the step size is chosen through an RS-232 session (one time programming step), they only require direction and step commands from the controller (like an arduino or similiar).
    • After further thought, I'm guessing that not only would these motors be overkill for this project, they might also have a negative effect on the idea of building 'a kit' since they do have the driver/controller builtin. This really increases the cost of the motor, and without the driver/controller being part of our kit it would probably become useless as noone would want to buy costly motors like these. TP
    • Actually, the controller interface for the RepRap stepper driver board ( http://www.reprap.org/bin/view/Main/Stepper_Motor_Driver_2_3 ) has the signals Min, Max, Dir, Enable, and Step - with Min/Max just routed straight through to the opto boards. So it sounds like we could probably wire your motors straight to the motherboard, OR get the RepRap stepper drivers with more standard steppers - with little to no redesign needed. --Cjdavis 19:26, 7 September 2009 (UTC)
    • These motors might be a lot more appropriate for this project, esp given the target cutting area: http://www.automationdirect.com/adc/Shopping/Catalog/Motion_Control/Stepper_Systems/Motors_-z-_Cables/STP-MTR-17048 ($19 each, minus shipping). Depending on the tool, the Z-axis motor might need to be a little beefier than this. Nice bonus - they come cabled with reasonable connectors. Being basic 4-wire steppers, they should work with any driver system chosen. TP
  • Frame: I have an Aerocool Lubic 4480 computer case kit, which was basically a set of slightly smaller t-slot aluminum extrusions. I think they are 5/8" square if I remember correctly, and there are 12 of the longest pieces, which are ~18" long. There should be plenty of pieces for a full design. We can at least mockup the design with them, but they should be just fine for a fully functional CNC. The design should be directly transferable to use with any standard t-slot extrusion available.

Brainstorming Links