CNC Machines for prop making

Just came accross this, a tabletop CNC machine.
http://makezine.com/2014/10/21/first-look-inventables-carvey/

Gattaca said:

Thanks Miker, I hadn't thought of those things. Didn't know about them either, I guess I thought it would be like the 3D printers, where the software took care of that sort of thing.

Click to expand...

I'm curious, if you didn't know about how 3D printing works, what did you expect? Type "make a stormtrooper helmet" into the program and off it goes?

All 3D fabrication machines - CNC mills/routers/laser cutters, 3D printers, so on - all have the same basic toolchain:

* Create your 3D model. You can do this in a CAD software or a 3D modeling program, depending on what you're making. If you can't make 3D models, learn. It's not rocket surgery. Being able to make your own models will extend the use of these machines a thousand fold. You can commission a model, and there are some available for free online at places like Thingiverse, but you're at the mercy of another person's skills and time if you go that route

* Load your 3D model into your CAM (computer aided manufacturing) software. This is the program that generates the paths for the tool - IE how the part is actually made by the machine. You may have to do manual pathing, you may have a program that does it for you. It really depends on what tool you are using and what software you're using. Most 3D printer CAM software (often called a "slicer", not to be confused with the 3D printing CAM/slicing software called Slic3r) will let you push 1 button and it will make the paths. CNC milling/routing is a bit more involved.

* Load your gcode that your CAM software created into your CNC controller. Make sure your machine is centered at zero if it doesn't do it automatically. Press go.

Yes, that is quite a bit of things to learn, but the technology will never be "just press go" like you might think it is. As others have reiterated, it is a tool, and like any tool you need to learn how to use it. You can do everything a CNC mill/router can do by hand, but they can do it much more quickly and with much more precision than you. The trade off is money and time learning a new tool.

I also use CamBam and Mach3 for the laser cutter and CNC mill I have access to. I learned how to use both of them in an afternoon.

msleeper said:

I'm curious, if you didn't know about how 3D printing works, what did you expect? Type "make a stormtrooper helmet" into the program and off it goes?

.

Click to expand...

That's kind of what I was hoping for, well not quite, I know that's not gonna happen. As I said earlier I have access to a 3D printer now, I do make my own 3D models (which I taught myself how to do with Tinkercad) and print those, so I have that part down. Some of the earlier reply's made me think I needed to do the slicing part but I get now that it's the programs that do that. You have to keep in mind I just learned how to down load music 3 months ago so throwing all this CAD and CAM stuff at me is a bit much. But I get what you're saying about learning to use the programs, and one day I will. I mostly wanted to know if people use these tools, what models and what programs they use. And thanks to many reply's I know more now then I did a few days ago.

Gattaca said:

That's kind of what I was hoping for, well not quite, I know that's not gonna happen. As I said earlier I have access to a 3D printer now, I do make my own 3D models (which I taught myself how to do with Tinkercad) and print those, so I have that part down. Some of the earlier reply's made me think I needed to do the slicing part but I get now that it's the programs that do that. You have to keep in mind I just learned how to down load music 3 months ago so throwing all this CAD and CAM stuff at me is a bit much. But I get what you're saying about learning to use the programs, and one day I will. I mostly wanted to know if people use these tools, what models and what programs they use. And thanks to many reply's I know more now then I did a few days ago.

Click to expand...

I get what you mean. In ye olden days, it was viable for you to write your own gcode (the tool paths used for your CNC mill to make) when the code lines were really short and simple, and in theory you still can. But the average 3D printer gcode file is something like 200,000 lines long, and CNC cutting at minimum is a few hundred.. So yeah, there are programs that do the actual gcode generation - but you do still have to tell them "okay these 3 parts are all one 'piece' and should be cut together". For 3D printing, Slic3r and similar programs are extremely easy and you can learn to use them in a matter of minutes. For other CNC stuff, you can learn the basics of the toolchain in a few hours. Obviously the more experienced you are and the more familiar you are with the tools (in this case, the software) then the better results you can produce. But that's the same for any tool, whether it's a bandsaw or a 5 axis CNC mill.

To go back to your original post, I think you can get a hobby grade desktop mill for your price range, and if you are willing to spend the time to learn the software then you will get a lot of value out of having it. If you can already create 3D models then you're well ahead of the curve. For CNC stuff I do recommend an actual CAD program. Something like Openscad is free, although it is more of a "CAD for programmers" than anything.

A CNC router is a fantastic tool for prop building (overall more useful than a 3D printer but that's another discussion) but you really must look beyond the cost of just the machine. Software, tooling, motor drivers (many machines like the one from Zen Tool Works don't include the motor drivers), dust collection (!) can jump the cost up considerably. Plus there is usually the need to prep raw materials to size, which can mean the need for a table saw, band saw, and drill press.

As far as what can be done with a CNC router, here are links to a couple of projects I've done with mine. The Kelvin Phaser was almost entirely done with CNC. The Blade Runner Blaster was about 50/50 CNC/3D Printing.

http://www.therpf.com/f9/star-trek-kelvin-phaser-project-109585/?highlight=kelvin+phaser+project

http://www.therpf.com/f9/blade-runn...133/?highlight=blade+runner+snub+nose+blaster

If you go a head and get a CNC router avoid the Carvey. Also, buy Aspire Vectric it will make your life much easier.

I don't know what kind of CNC machine you could get for $600 dollars that could do any good. There might be a kit out there that you could put together that could cut softer materials. I purchased my own CNC router a year ago as a kit and put it all together, with software and accessories, I'm good to go for about $5000 invested. It all matters what you want it to be able to do. Then there's tooling for the machine...more commonly referred to as "bits". They add up...depending again on what you cut...I use three materials regularly.
Aluminum, goes through bits pretty fast...I can get about a month out of a regularly used bit. MDF, great stuff, easy to cut and easy to work with. I can go for quite a while on a bit for MDF. Have yet to actually replace one. Green floral foam...yeah...it's cheap, does nothing to dull the bits, and can be used for molding....I love it...save for the particles it throws in the air.
I mean..you could possibly have a hobby machine itself for $600 that could do some rudimentary cuts composed of cheap pieces from China. This may be true. I can't see how it would be a worthwhile investment personally. I would look around for a community college or fab-lab to see if you can get access to one that is a higher level of quality for a lower stipend until your have more to invest and understand the technology better.

I've just bought a Shapeoko 3 mainly for shaping chemi wood, its a desk top hobby thing. After getting some 3D cam soft ware ( it comes with 2.5 ) it going to $1500. ITs had good reviews but I won't say till its in my hands and cutting.. will let you know