CNC Milling of parts
R&D owns a 300x400mmx50mm aluminium CNC machine. It has been used to successfully make PCBs and parts out of plastic and aluminium. For more information see The Little CNC.
Kean has a small CNC mill used for making PCB's and fabrication of small parts from PCB, plastic, and aluminium.
If you are interested in a workshop showing PCB isolation routing and techniques for making small parts from plastic, then add a comment below. It will need to be held somewhere we can make some noise and dust. If it is a small group, then my home workshop might be possible, but the system is somewhat portable if another venue is available.
Photos:
Taig Milling Machine
The mill is a Taig CNC 2000 Long Bed Mill (with Stepper motors) - similar to the model shown at link below. Accuracy is close to 0.01mm
I bought this mill 2nd hand on ebay for a really good price, compared to a newly imported one. It was also about the same as as upgrading my existing mill to CNC. It needed some work, but I got it running pretty quickly and it is very accurate so must have had little prior use.
My workbench is pretty messy as usual...
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Sample PCB
single sided for a surface mount PIC16F88
size is approx 40 x 30 mm
The first photo shows the board after isolation routing on the mill, and has been tin plated
The second photo shows the populated board with the PIC CPU, and some SMD parts.
This was revision 1, and you can see it has already had some alterations
I've successfully made boards as small as 7mm diameter for a surface mount light sensor.
The blank PCB is mounted on a plastic backing plate (to allow drilling through). A recess is cut out of the plastic to hold the PCB, which is held in place during milling by the double sided sticky tape.
A V shaped router bit is used to remove the material between tracks & pads - this board probably took 15 minutes, so it isn't quick. A "normal" router bit of 1.27mm diameter was then used to cut the outline. The router bits are 1/8" shank, are made from carbide, and can easily cost $20+ each.
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Sample 2D Part
optical vane interrupter made from PCB material
made like a PCB, but in this case we just used a 1.27mm router bit to cut the outline and holes
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Sample 3D Part
scientific intrument prototype housing made from Delrin
the difficulty with making parts like this is working out how to hold the material while milling, and to accurately locate the starting point of the job - in this case the centre of the 40mm diameter round delrin stock. The centre recess was cut in a spiral from centre out in about 6 passes of 4mm depth.
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PCB Drills and End Mills
A few of my most commonly used minature drills and mills used for PCB manufacture.
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My other Milling machine and Lathe
This milling machine is not CNC, so is good for a quick modification without having to draw something up in CAD. Much more accurate than a standard drill press, but can also be used with end mills to cut slots or flat surfaces.
My rarely used drill press is in the background under the plastic - it is still useful for bigger jobs, especially woodwork.
The lathe is a 2nd hand machine that desperately needs an overhaul/realignment.
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Some resources:
http://www.cadsoftusa.com/ - Eagle CAD for PCB design and schematic capture
http://www.pcbgcode.org/ - Program to get CNC G-code from Eagle to do isolation routing of a PCB
http://machsupport.com/ - Mach3 software drives the motors on the mill per the G-code program
http://www.linuxcnc.org/ - EMC is the equivalent to Mach3 for Linux
http://www.millpcbs.com/ - Explains how to get it all working
http://www.cambam.co.uk/ - A good CAM program for setup of milling process for 2D and 3D parts
http://www.cnccookbook.com/ - All kinds of useful info
http://www.cnczone.com/ - The best CNC forum in existance!
Comments (7)
Adriaan Swanepoel said
at 8:47 am on May 5, 2009
I would definitely be interested in a workshop. After that I might have a few questions for you about converting my mill to CNC.
Gavin Smith said
at 9:11 am on May 5, 2009
Looking forward to it, Kean. -- Gavin.
Phillip Wright said
at 11:59 am on May 5, 2009
Coun't me in
Rebecca Owen said
at 11:44 am on May 8, 2009
Love the idea of automated part fabrication! I would definitely try to attend any group sessions on this topic. :)
David Vernon said
at 12:45 pm on May 8, 2009
Count me in!
carson.au@... said
at 9:10 pm on May 10, 2009
Definitely count me in :D
Jaye Gallagher said
at 3:42 pm on May 26, 2009
This looks neat. Love to attend.
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