CAD to CNC machine? (Newbie's question)

Hi,
I am a newbie in mechanical design and I may have to design some mechanical parts in the future for my work. Now I am looking for a CAD
software package for our company. My boss told me I should choose a CAD software that could export file formats being widely accepted by local machine shops. But when I called those shops, they said all they need was a drawing from me. It doesn't have to be a computer file, a drawing on paper will be just fine.
Now my questions are:
Is it common for machine shops accept files generated from CAD tools and import them directly into CNC machine? (Or they still have to program CNC machine by hand even when I give them computer files?)
Thank you very much for your time.
Hua
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Some machines are capable of importing CAD files and then using the control to program the part. Our machines are set up to receive .dxf files, but we never use the built in system, so we never ask for or create .dxf files. Sometimes it's what we get, but it's not our favorite format. Many shops are able to use iges (.igs) files. There are some groups trying to put emphasis on the step file format, but for the forseeable fututre iges will probably remain the most widely acceptable. One way you can research this is to find out what CAM systems are being used by the shops that would make parts for you, and then try to get sample software (demo discs) for those systems. This would allow you to at least see which file formats were common amongst the various systems, and could even enable you to try the files you create before sending them out. A big problem shops run into is just getting a file they can read, which may be why the shops you contacted just wanted paper drawings. Paper drawings also have the benefit of tolerances and other types of notes, which are usually not included with CAD files, but should be.
--

Later,

Charlie
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you can try the software "hypermill", it integrates itself within mechanical desktop. it will generate you M and G codes for your part and will send it to your CNC.
i have not really been able to use the software, i think that you need to input material type, feed rates etc... -- Hasta Luego
Irshaad (Faster than Bruce Lee)
remove INVALID to reply snipped-for-privacy@INVALIDsofthome.net

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Hua,
There is some very clever software out there. One of the cleverest I have seen is Pro Engineer by PTC. It is a professional 3D modeller but it also has built in ish FEA and more relevant to you a module that allow you generate CNC programs from your designs. It basically work like this: Model part in 3D Create the cuts on the CAD as they are in the machine Save the part cut file Covert it to the G and M code for the machine Enter it in the machine (Direct by LAN connection or download it in manually using a Pision with an RS232 Cable (Babbage would be proud)) Put the material in and press the button and then take out the part (Yeh right if you believe that you will believe anything)
You usually require a bit of code to convert it to the desired machine ie. Mazak 770. Al this does is take the output file and convert it to machine specific G and M codes. But PTC forums have some good resource for this (if you get luck). ProE also has add on modules to help automatically create dies, moulding and sheet metal tools.
However the major drawbacks are it normally takes a long time to learn and usally you modify the G and M codes to get exactly what you want. It also is not as good as a pencil and paper for speed and efficiency if the part you require is simple. It also costs a lot of money. If you want to take a look contact PTC for a demo (student) copy it's usually free but you cannot save your work and use any of the additional features discussed.
Well in brief - Stick to paper and pen unless CAD gives a benefit (use your judgement) - If you have to go CAD keep it simple and cheap ie Turbo Cad is good and very cheap. - Export DXF or IGS as these are widely used formats - If you have money and time ProE is good and can give you great benefits (but be warned). - And finally what was the question?
Yes they still will have to program G and M Codes but may use some conversion software to create the initial CNC program form the drawings.
DXF are not directly importable to CNC machines.
On 10 Feb 2004 08:39:19 -0800, snipped-for-privacy@yahoo.ca (Hua) wrote:

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http://cnc-programming-tips.blogspot.ca/2014/11/m97-m98-m99-sub-programs-or-sub-routines.html check for learning CNC
poornachandra
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