Testing and Validating a New Vertical Milling Machine

[gmsqengineer]

I am a newbie in the mechanical industry and am learning as I go. I have a supplier who is supplying a new shaft to us using aircraft quality material being in an automotive application. They have recently purchased a new Vertical mill cnc machine and I need to audit it. I am just not sure what to look for, besides capability studys. The machine will mill a slot and then add square features to the shaft. Any help or checklists i can refere to would be much appreciated.

 

[Wes Bucey]

Re: Help New Vertical Milling Machine

I am a newbie in the mechanical industry and am learning as I go. I have a supplier who is supplying a new shaft to us using aircraft quality material being in an automotive application. They have recently purchased a new Vertical mill cnc machine and I need to audit it. I am just not sure what to look for, besides capability studys. The machine will mill a slot and then add square features to the shaft. Any help or checklists i can refere to would be much appreciated.

Vertical mills with CNC are wonderful machines. When I was in the precision machining business, even our most sophisticated customers did not attempt to audit a MACHINE. What our customers audited was our PROCESS. Depending on how many of these shafts your organization is purchasing (per lot and per total order), you would probably be best served by examining PPAP and First Article before approving continuation of production. Frankly, the capability of the machine, itself, is probably not in question. The variables which will affect the outcome are tool bit selection, feeds, speeds, cutting fluid, in-process inspection, SPC, inspection instrumentation, training of machine operators and inspectors - all of which should be documented in the Control Plan for the part.

You might gain some insight into the interaction between supplier and customer by reading through these posts I made some time ago.

Some good answers so far.

From the description given in the first post, we are dealing with a contract machining environment. Almost by definition, the use of CNC machining and turning centers describes a precision machining environment.

In a precision machining environment, it is not a good practice for in-process inspection to be informal, rather, it should be part of a well-thought out Control Plan for each different product, taking into consideration such things as critical characteristic dictated by the customer and machining "checkpoints" before a final dimension.

Following are links to posts about some practices I deployed in a precision machining environment - perhaps something similar will work for your organization.

Quote:
Wes Bucey on an efficient shop - empowerment (This is a single post (#18) in a longer thread - the url leads directly to the post - it is associated with a follow-up in post #20)
https://elsmar.com/Forums/showpost.php?p=105469&postcount=18
Wes Bucey on quoting and empowerment (This is a single post (#20) in a longer thread - the url leads directly to the post)
https://elsmar.com/Forums/showpost.php?p=105566&postcount=20

In process and final inspection:
Re: Inspection Dimensional Check Sheets - Over 500 part numbers

Who inspects?
I, too, ran a shop where primary responsibility...

Control Charts
In my high tech machining business (1990 -2000),...

What makes sense?
In point of fact, I have seen several operations...

 

[dsanabria]

I am a newbie in the mechanical industry and am learning as I go. I have a supplier who is supplying a new shaft to us using aircraft quality material being in an automotive application. They have recently purchased a new Vertical mill cnc machine and I need to audit it. I am just not sure what to look for, besides capability studys. The machine will mill a slot and then add square features to the shaft. Any help or checklists i can refere to would be much appreciated.

in addition - meet the requirements of AS9102.

 

[Jim Wynne]

in addition - meet the requirements of AS9102.

The OP said that aircraft-quality material is being used in an automotive application.

 

[Jim Wynne]

I am a newbie in the mechanical industry and am learning as I go. I have a supplier who is supplying a new shaft to us using aircraft quality material being in an automotive application. They have recently purchased a new Vertical mill cnc machine and I need to audit it. I am just not sure what to look for, besides capability studys. The machine will mill a slot and then add square features to the shaft. Any help or checklists i can refere to would be much appreciated.

I'll second Wes's advice that it's the process and not the machine that should be qualified. If this is an automotive application, has the supplier been producing the part using a different manufacturing method? Has PPAP been submitted? If you give us more information on the circumstances we can provide better advice.

 

[Big Jim]

And a first article can be used to help qualify a new machine. First article does not mean that you have to follow everything in AS9102 though, although it could be used for guidance.

If they are an aerospace supplier, they would already be accustomed to performing first articles and could be a good approach even in this situation.

 

[dsanabria]

The OP said that aircraft-quality material is being used in an automotive application.

Sorry - I must be in the wrong forum - can you direct me to the AEROSPACE forum? -

 

[Jim Wynne]

Sorry - I must be in the wrong forum - can you direct me to the AEROSPACE forum? -

Oops. This isn't the first time I failed to pay attention to the forum a question was posted in. Carry on.

 

[JaxQC]

Validating = IQ, OQ, PQ
IQ – Install of the machine “power to the machine, install”
OQ – It may be in the details but since we’re talking aerospace I have to pull out the phrase “the capability of the machine, itself, is probably not in question”. While it might not be, without evidence proving contrary, it is in question. Regardless now is the time to get a baseline of the machine to use for PM of wear & comparing after crashes (which will happen eventually). More than one machine gets delivered with an unresolved issue.
· Low tech – Cut test (cut a Circle, Square, Diamond & see how much do they vary from perfect)
· Better – Ballbar test (looks at servo transition among other issues but only over small operating area at a time) (my personnal choice for the money)
· Better still – laser (volumetric ie.. over entire area)
PQ – FA – First Article on the specific part (includes program, speeds/feeds, fixturing, tooling etc)

 

[dsanabria]

I am a newbie in the mechanical industry and am learning as I go. I have a supplier who is supplying a new shaft to us using aircraft quality material being in an automotive application. They have recently purchased a new Vertical mill cnc machine and I need to audit it. I am just not sure what to look for, besides capability studys. The machine will mill a slot and then add square features to the shaft. Any help or checklists i can refere to would be much appreciated.

OK - Aerospace Forum Thinking

Are you auditing the mechanics of the machine or the output of the machine

AS9100 C

7.5.1.3 Control of Production Equipment, Tools and Software Programs

Production equipment, tools and software programs used to automate and control/monitor product realization processes, shall be validated prior to release for production and shall be maintained.

Storage requirements, including periodic preservation/condition checks, shall be defined for production equipment or tooling in storage.


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