acceptance criteria for a vertical Machining center

[Johnnymentero]

I will buy a vertical machining center , but I have to write an acceptance criteria document , in order to be clear with all cnc machines suppliers . does anybody have one %-)

 

[looslib]

NAS-979 (National Aerospace Standard) is a spec for testing a CNC machine. It involved a circle and a square at 45 degrees and some other cuts.

Spec Title: Uniform Cutting Tests - NAS Series Metal Cutting Equipment Specifications

Spec Purpose: THIS SPECIFICATION PROVIDES A STANDARD FOR THE SELECTION OF CUTTING TESTS REQUIRED TO EVALUATE THE PERFORMANCE OF CONVENTIONAL AND NUMERICALLY CONTROLLED MACHINE TOOLS NOTED IN PARAGRAPH 1.2, EXCLUDING DRILLING AND TURNING MACHINES, AND TO PROVIDE A STANDARD FORMAT FOR RECORDING AND REPORTING ACTUAL PERFORMANCE RESULTS.

http://aero-defense.ihs.com/document/abstract/JQBUCAAAAAAAAAAA

"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[is2634]

This is a very large subject. See ISO standard 230 sections 1-11 which is over 1" thick when printed.

You have to customize it to your needs. I start with my environment "How big a doorway must it fit through?" What weight can your floor with stand?

Then decide if you want to evaluate performance based on test cuts (your part(s) or a designed test part) or on measurements using instruments such as a ball bar or laser interferometer.

Personally I do not like test cuts because as soon as one fails there is no end to the excuses of why and the supplier wants to do it over again.

The simple way to go is grab a brochure of a couple contenders and list the specs they call out and just change the numbers to the values you require. The danger here is if you don't know what you want, you might not get it.