Since the topic of CNC mills has raised its head here, I thought I'd share this with the DIYDrones community.
One of the things those who are considering this need to be aware of is that the toolpathing of complex shapes isn't a trivial exercise. I would be interested to know if anyone has experience with any open-source surfacing toolpathing packages - please comment below!
I am fortunate to have access to MasterCAM V9 - old-fashioned as it is - but only in a 2.5D package. I then butcher my SolidWorks models into such a form that I can generate an IGES wireframe which represents the basis of a toolpath. I then import this into MasterCAM and labouriously reconstruct it into a contiguous chain which the 2.5D recognises as a contour path. This generates an absolute monster long .NC file which I drip-feed into the Siemens Sinumerik 820D controller that runs the mill I'm using.
The other critical point to this type of work is the machine envelope is everything. Once you start using multiple setups to accomodate an oversize workpiece, you are adding hours and hours to the project, not to mention a bunch of risk and the inevitable mis-match of complex surfaces which will need filling and hand finishing.
As far as MDF goes, it's absolutely not a bad material to machine and is an easily hand-worked end-product which can produce a perfect finish but I do worry about the health risks and it does make an unholy mess. I'd consider using PVC or, if you can afford it, alumnium billet. At approximately AUD10/kg, it's not cheap though...
So, after going of half-cocked with the making of this plug, I have since revised the design pretty significantly, so now it's only a learning exercise and a lovely desk ornament! C'est la vie!
Anyway, I hope this is helpful and interesting.
Comments
nice machine here is my home made cnc machine also have a 4 axis hotwire machine .mc9 ? step up to x10 you will get things done way faster . nice work ! also checkout linuxcnc I use a pc to drive my servos or steppers . you can at least DNC to your seimens controller with linuxcnc and also mach3 . get way more ram for your 3d paths and nice 3D tool path display .
Andrew,
For CAM software I use PyCAM. While I don't have much experience with the program yet, I have used it a few times to get an idea of how it works. The nice thing is it will pull in 3D models in STL format. This works well for me. I then send the G Code to EMC. Right now I am working on finishing my Solsylva 24" routing table. To me it just made sense to need a CNC table if I was going to be doing diy drones. :) Here is a link from EMC that might be of some use.
Software List
Hope that helps
Mo
I have some very promising revisions to the design now in XFLR5. So promising that I don't really believe then and I'm learning OpenFOAM to be able to confirm the flight characteristics somewhat better before I cut any more toolong
Can't wait to see your final plane fly!
wow that is a learning curve! Looks very nicely done. Too bad you need to redo it.... but that is the "joy" of prototypes. I am sure the end result will be worth it!
Keep us updated
Dany