Customer Print Spec.
Customer Print Spec.
(OP)
I have a callout for a .250 dia. hole with the letters w.h. next to it can anyone please tell me what it means. The hole appears to have no functional purpose.
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RE: Customer Print Spec.
Seriously, if hole serves no purpose, it can be used to hang the part for painting; then it means something like "wire hanger".
Still you are better off asking person/organization that produced the drawing.
RE: Customer Print Spec.
RE: Customer Print Spec.
RE: Customer Print Spec.
RE: Customer Print Spec.
RE: Customer Print Spec.
After you make the part and the customer complains because you got it wrong, do you really want to tell him you made it that way because some guys on a forum said to? Not good.
Ask the customer. He is the one that decides if the part is right or not. He will appreciate your asking rather than assuming something.
RE: Customer Print Spec.
As Jboggs said, only the customer can give you the correct definition.
Fundamentally, if you are a contract house making parts to your customer's prints, why are you questioning what the customer has ordered? Make it to the print, ship it and get paid.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Customer Print Spec.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Customer Print Spec.
Now, when all the experts are here, will somebody educate me: what kind of "special treatment" the weep hole is getting that justifies using its own unique call-out?
RE: Customer Print Spec.
RE: Customer Print Spec.
This is about what I expected, and here are my next questions:
As a fan of ISO 2768 (and for some other reasons) I am interested in topics like "industry standards", "customary accuracy", "critical- and non-critical dimensions", etc., and how they connect to the world of strict written standards.
Did you try to actually specify loose tolerances, or specify no tolerance at all and rely on "title block" or "general tolerances" instead of using non-standard designations?
What in yours (and anyone else's) opinion is the best way to tell the shop to just keep "effortless" level of quality?
Are the benefits really that great, for example, in specifying loose tolerances for 'some' holes, if 'all' the holes will be produced on the same CNC?
RE: Customer Print Spec.
If all holes are machined on the same CNC setup, then in actuality all those features will be precisely located and within feature size tolerances. By "precisely" I am saying that most CNC machining centers hold feature tolerances within ±.0005 easily unless it is somehow out of calibration.
Where I have used differing tolerance ranges and weep hole designators is in instances where the part will have multiple machining operations done to it using multiple setups. The advantage of specifying looser tolerances where multiple setups and machining operations are involved is that it allows the manufacturer (not always the same as where it was designed) some leniency in using whatever manufacturing process they deem capable of holding those tolerances.
The biggest advantage to accurately tolerancing each component feature based on its intended function and importance, is that you do not always know where a particular part will be manufactured, or exactly what processes will be used. Specifying CNC-capable tolerances on non-critical features may well drive part cost up substantially at a machine shop where they do not have the same CNC capabilities and have to rely on manually operated milling, drilling or turning centers.
Having said all that, it is my belief that is always best practice to individually tolerance critical features and let non-critical features fall back to default title block tolerance ranges. This is a happy balance that allows for least cost in most situations.
I hope this was helpful.
RE: Customer Print Spec.
Thanks a lot tz,
I wish more people could see it your way.
RE: Customer Print Spec.
TZ101, nice summary. The other related aspect is you may design & tolerance for a certain machine/process capability but say for some reason that tool is unavailable and to meet schedule they want to use some other tools/process that aren't as accurate/preccise. I've had real life examples of this.
What is Engineering anyway: faq1088-1484