A question (or two!) about CNC machines

[CanadianRyGuy]

So I just found through talking to the owner that two units down from my work (industrial park type area) he has a CNC machine and would be willing to let me use it, all he would need is a design and he can program is for me to make cuts for an arcade. Now, I have zero experience with these things and have no idea how they work or exactly what he would need from me. Since the guy is basically doing me a favour, I would like for him to do as little as possible. So my question is, what exactly do I need to provide him with? I'm guessing it's some sort of CAD file or something with all the measurements in it that he just uploads into the machine and it spits out cut pieces of wood? I have no design experience either, can someone point me to any complete designs that already exist that I can give to him for a full size upright cab?

[HaRuMaN]

You'll need a design, likely in Autocad or compatible (dwg file).  The software he likely uses with his CNC will translate that to machine code for the CNC to run. 

[Knave Jack]

A lot depends on what type of CNC machine your are talking about. CNC mills and lathes run G code.  There is software that can translate CAD usually a DXF to a usable format. CNC routers usually have their own coding that they translate from Illustrator or CorelDraw files. They will usually also take a DXF. Waterjets and lasers (the big metal cutting kind) usually use DXF's and the small engraving/cutting lasers usually use Illustrator, CorelDraw, and DXF. DWG is the native autocad format, but most of the cutting machines dont use it. For every thing but the mill and lathe (and maybe a 5 axis CNC router) you need a 2D or flat drawing. Converting from 3D (or solid modeling) usually doesnt work well.
Good luck
Mike

[Locke141]

We have two small CNC's at work I use sometimes. I use Illustrator and export to .DXF. You should ask him what what would work best for him. 

[RandyT]

As others have stated, a 1:1 scale DXF file is going to be the most you can do to help the operator where the file is concerned.  Make sure it's generated by a good CAD application.  A lot of times, the DXF files generated by drawing programs (like CorelDraw) have lots of nasty problems.  Disjointed and duplicated line segments seem to be the most common issues.  Also, some 3D and solid modeling software are fine sources, but again, much depends on the application itself.  If the cabinet is modeled as an assembly using discrete panels (like you would actually build the physical cabinet), these individual parts can usually be exported as two dimensional outlines when the proper face is selected.  With solid modeling, this is usually referred to as a "drawing".

Forget G-Code or other machining languages.  Each machine is different and will have it's own idea of the "flavor" of G-Code it wants to use.  This is the realm of the operator, so leave it to him.

Also, try to take things like bit diameter into consideration with your design.  If you design something with sharp inside corners, and that is 100% necessary for your design to work, it's not going to without some manual cleanup.  Think about how the machine works, and design around the limitations.  Also, for all but really high end machines, the fewer cutting tool changes, the happier the operator will be.

[ChanceKJ]

On a side note, I know we're like the second largest country in the world by land mass, but where are you located?

[CanadianRyGuy]

Thank you for all the informative responses!

I was hoping I could maybe get away with something like the flat 2D drawings I've seen around here which show all the dimensions/angles, etc. but if that's gonna be too much effort for him than I shall find another way. Would a novice like myself be able to convert one of these drawings into a more suitable format using an easy/freely available program?

On a side note, I know we're like the second largest country in the world by land mass

Yeah, we are! 
I'm in Toronto 

[ChanceKJ]

Cool, you're not far from Rick at GameRoomDesigns. He's got a CnC too.

[CanadianRyGuy]

Yeah I actually sent him an email, but don't think I ever got a reply.

He just has the one design of upright cabinet that I'm not a huge fan of. Prefer more of a Simpsons/TMNT kind of look to the cab. I asked him if he was planning to introduce any other designs. Do you know if he does custom stuff? I was also hoping to use 3/4" MDF, which I don't think he uses on his designs.

[ChanceKJ]

Send him a private message here on the forums. He's quite active. Might just be really busy. Great guy to work with for sure!

[Rick]

Yeah I actually sent him an email, but don't think I ever got a reply. He just has the one design of upright cabinet that I'm not a huge fan of. Prefer more of a Simpsons/TMNT kind of look to the cab. I asked him if he was planning to introduce any other designs. Do you know if he does custom stuff? I was also hoping to use 3/4" MDF, which I don't think he uses on his designs.

I'm sorry, but I checked and I'm having trouble finding your original e-mail. If you want to send me another to arcadeshop@gameroomdesigns.ca, we can try that again.

To answer your questions, I do hope to have more designs available in the future for the full-size cabinet, but at this time, I haven't had the opportunity to create them as yet. I am also working to implement 'true' reproductions of a number of classic designs, so perhaps this might help out as well.

As for 3/4" MDF, for my existing designs I would personally prefer to stick with 5/8", as the measurements on the mortises and the sizes of the external panels would all need to be completely reworked. For future reproductions, this may be easier to implement.