File types used for CNC work?

M

Mirage416

New member
I have a part which I need produced in bulk quantity. I machined the prototype and now my next step I believe is submitting a design file to some CNC shops to get a quote on the parts run. The part has a very simple design, basically a rectangular cube with slanted sides, and four large holes bored and thread tapped through the middle. It will be constructed from solid PVC square bar.

I have Autodesk Inventor 2010. I would like to design the part using the program, but could someone suggest which design file extension would most likely be accepted by current CNC shops to quote and produce the part with?

Thank you
 
Most if not all CNC machines operate off "G-Code"

There are many machines that are set up so the operator can write the code, tool up, then orient the machine and press the "GO Button".

Some Machines will accept Disc, tapes, etc and use code written by after market software such as Gibbs Cam, Master Cam, ect.

Nat Lambeth
 
He's asking what drawing type, not about the G-code.

You can send it as a DXF, DWG, PDF or even a JPG. They simply need a print to work from. Even if you were to write G code and give it to em, nobody could use it. For what machine would you write the code? How would you know what machine they'd do it on? See what I mean.

So, draw a print. You can use tablet paper for all they care. List a datum and all dimensions and everybody's happy.

And, be certain to either list a tolerance on dimensions, or tell what that tolerance is in your notes on the print. Or, you can just say, "Machine to general machining standards" and let them set the tolerance. They're going to try to hit the mean anyway, but if there is little room for error, they want to know which direction they're allowed to err.

PS. Specifying dimensions to 4 decimal places and not specifying a tolerance means hold 4 decimals. When you send this print, they're not going to call you up to ask if what you drew is really what you want. They will quote accordingly. So, draw accordingly.
 
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4Mesh is correct, If you have a complex 3-D part, then a I would need a DXF or STEP file in order to generate a program on my CAM system. However, if the part has basic 2-D geometry, then only a detailed blueprint would be necessary. I would be happy to provide you with a quote for any precision machining work, regardless of it's complexity or quanity.
 
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4Mesh said:
He's asking what drawing type, not about the G-code.

You can send it as a DXF, DWG, PDF or even a JPG. They simply need a print to work from. Even if you were to write G code and give it to em, nobody could use it. For what machine would you write the code? How would you know what machine they'd do it on? See what I mean.

So, draw a print. You can use tablet paper for all they care. List a datum and all dimensions and everybody's happy.

And, be certain to either list a tolerance on dimensions, or tell what that tolerance is in your notes on the print. Or, you can just say, "Machine to general machining standards" and let them set the tolerance. They're going to try to hit the mean anyway, but if there is little room for error, they want to know which direction they're allowed to err.

PS. Specifying dimensions to 4 decimal places and not specifying a tolerance means hold 4 decimals. When you send this print, they're not going to call you up to ask if what you drew is really what you want. They will quote accordingly. So, draw accordingly.
Click to expand...

Given the ability to produce it the IGES is fully capable. Where something like DXF is only 2D, IGES provides full 3D piecepart data.

There may now be more modern CAD/CAM interfaces like "solids" now (it has been 12 years since I've dealt with CAD/CAM).
 
Jerry, well, and others...

I was drawing some conclusions on what the guy is trying to do. I figured if he was here asking what format to use to send a print, it was a safe bet he didn't have software that was $5000/seat at his disposal. I'm sure there's 3D packages out there. But 3D parts have been made before without 3D software. His best bet is to either use Autocad or one of its variants that are free, or draw it on a piece of paper. The shop that makes the part will certainly be able to do their own programming for the CNC. For a simple part like this guy is talking about, there's a good chance the operator is going to type it up on the machine, hit cycle start, and stand back.
 
Thanks a lot for suggestions.

I started modeling the part using the IPT part file in Inventor. This looks fairly straightforward. It was what file type the Autodesk tech on Youtube was showing he likes to use for most simple parts in the tutorial vid series. I almost have the part model done. I have to tweak a few things tonight and tomorrow with the design but I mostly have the production design complete. This program is awesome. I feel with a little time, designing parts in it will be easy. The way it guides you around the design makes the learning process pretty simple.

The way I understand it is once I model the part in 3D, I will be able to submit 2D drafts of the part using the program to make different file outputs. I was a little confused at first, but it now looks like the program is very versatile at outputting whatever the machinist needs.
 
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You may like Inventor at first while doing simple plain jane parts. Once you evolve to complex assemblies your love affair may be over, especially if you are trying to make money with it. Just because you created this file that "should" be readable by the machine shops software, don't mean that it will, and if it's got some errors you can really have problems.

Autocad and inventor were designed to originally be architecture software and civil eng,,, and after all this time it still has plenty of problems communicating with software that is developed for mechanical work. You will also run into a lot of shops and designers that don't want any thing to do with Inventor.

What, then, happens is you will be forced to become software poor, that's buying what everyone uses, as nothing pisses off a large customer more than you as a vendor not being able to work with their cad guys. I have to have various high end software packages , from cad to programing, to factory communication.... gota love it when some jackass engineer puts a Control Logix controller on a machine with 100 I/O. or uses DeviceNet, or Twin Cat on top of it, when plain ole Ethernet will do.......moist home computers are Ethernet now days, simple, until a "professional" gets his fingers in it.

I know years ago when Catia was the rage, and some automotive purchasers would send out their RFQ on a CD with all the files in Catia and wanted them returned with your quote in Autocad..........they did that to weed out the riffraf.
 
We produce our parts in dxf and iges files. The CNC shops are very happy with it. I think 4mesh is giving you good advice. You could spend more money on a CAD program than you will ever make on your parts.Talk to the folks that you are using to produce your parts.
Butch
 
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