What is your method of checking parts?

A

awaqa909

Registered
Registered
Joined
Jan 28, 2017
Messages
52
Every first set of parts, we have to check them and fill out a inspection sheet. This particular part is supposed to be very reliable. We are running 2 parts per vice, 4 parts total, and I liked number 4 barely, but number 3 was off if I remember right. As I'm going though the sheet, there are like 20 different dimensions that I have to check. 4 drilled holes, 2 different sizes, then a smaller tapped hole x8 or something. I'm tying to check these and it just feels so dang slow.

What is your method of checking parts? Normally I don't do the inspection sheet. I just check every 5th to 10th part and when I do, I just make a cheat sheet. This hole diameter is X and radius of hole is Y. This dimension is supposed to be .500" but the hole is say .125" radius, so I would write .375" is what it should measure as. Then so on. I know some people do it like this, they measure the part, find out the hole radius and add it to the measurement and compare it to the plans. I just find this to be very slow and difficult.

Even with my cheat sheet I feel like I'm being rushed sometimes... What is your method of checking parts? I normally have to do 50+ parts.


Thanks,
Awaqa909 "Hit the green button."
 
Go-No Go gauges are good for quick inspection of holes. Pin gauges will work in a pinch. As far as hole location, measuring to a datum point from the hole edge is the best way. First confirm the hole diameter, then measure to the datum. First articles should be measured completely, then spot checks should be OK, unless your company policy or part requirement requires more in depth inspection. If that's the case, then just take the time to do what's required. If your shop is ISO 9001 then the paperwork specifies the inspection parameters at each step in the process.

If you are having problems holding tolerance then you need to look at the fixture, the offsets, the tooling, the G-code, or the machine. On any run I normally measure the first part(s), then I expect the machine to cut the rest of them the same way.

I don't run too many production runs, but I did a run the other day, 36 parts, 4 parts in a single vice fixture, 303 stainless. Face, rough pocket/slot, finish pocket/slot, countersink, chamfer edge in and out, +/- 0.0005 on the ID, +/- 0.001 on the pocket depth. I measured the first batch to confirm the setup, then ran the rest of the job. I did spot check, but the critical dimensions were all the same. The last parts were identical to the first.
 
and depending on clearances, you could make a go/nogo jig to check multiple hole locations at once maybe?
 
"909",

I see you are down in my neck of the woods. Welcome!

Not knowing all of the details of the part your'e making, it's kind of hard to say if there is a quicker way to inspect without more details. And please don't post the drawing here, that could get you in trouble. This is where you need to get good with the engineer that designed the part if he/she is available to discuss details of the part. They can be of help most of the time. The customer/engineer needs to note the critical dimensions including hole locations so you know what to shoot for. Sounds like the drawing does not have any geometric tolerancing spelled out for you to go by? The stuff I work with, I require the shop to qualify the first part, do a mid run check, re-check if inserts/tooling is changed, and a final. Sampling is pretty much per the old military standard which is now been adopted by ISO. Bottom line is, "Do you meet or exceed your customers expectation on the quality of product provided?" You may not have any choice but to check the part as you mentioned above.

Guys gave some very good examples of things that could be implemented to help speed up the inspection process.

Good luck!
 
You must log in or register to reply here.
Back
Top