What's your First Piece Inspection Process?

The last few shops I've worked for have had incredibly slow moving first piece inspection processes. You run your first part, put it in QC then wait for it to come out, trying to do something else whole you wait. And these are short run shops, I would understand more inspection time if you're running in the hundreds or thousands.

Is this a normal thing? How does your company flow the first piece inspection process?

I had the bright idea of hiring the former inspection manger from Rockwell to come to China and teach inspection. What an absolute nightmare that was. He came in and set the QA standards to those of Rockwell but in a prototype company. The policy was bring the part in with the router, set on a specific surface plate for 3 hours so it could adjust to the room temp, no more than one person non QA allowed in at a time so the room temp and humidity stayed the same and then wait outside for the results. It damn near brought the company to a standstill. I tried to explain to him that the machine sitting idle would change dimensions then I was told "Not his problem". He lasted about a week before being sent back stateside. Then I had to undo the mess he taught everyone.

I wound up hiring the QC manager from Milwaukee power tools after that and he put a very simple process in place just using peer checks and several quality auditors on the shop floor just roaming around checking. They had mobile surface plates with full inspection gear to do sample checks. If there was a discrepancy then it was taken into the lab for a CMM inspection. Peer checking has just streamlined the whole process. Everyone in the shop has a QC stamp and are accountable for the checks so usually nobody skipped one.

I worked for a aerospace connector manufacturer that everyone had a stamp and did their own first articles. I think what should be done depends on the situation. If the parts are simple with low material costs a trusted operator should be able to let her rip while the part is waiting in inspection. On the other hand if we are talking a large complex part out of $1500 chunk of peek plastic maybe it should have another set of eyes look at it before it is ran.

At our shop (8-10 men running CNC machines, about 2/3 low-qty job shop and 1/3 production), first-piece checks (done at each operation) are done by the man running the job and a coworker, or manager if others are tied up. They sign their initials to the paperwork. Although it does tie up men at times, it sounds much easier on productivity than sending it to a "QC department"...

We used to have a quality manager, we joked about him being a quality mismanager. In all honesty, him being there made the operators more lax about checking - sad part is, he did not catch everything at the shipping table, it seemed like more parts went out bad then than before he came along... didn't last too long.

A few years back? There was no QC process... it was all left up to the man running the job. A second opinion might be acquired on one particularly tight dimension if need be, but that's it. We didn't have that much issue. But as time has gone on, volume has increased, something does have to be done about it... having first-piece/op checks between operators seems to be best for us.

We make relatively complex parts for aerospace. Our process is to run the first part and bring it to inspection to get bought off.

But we have a production limit where the machinist can keep running before the inspection is complete based on the risk in the part. Complicated casting, they can't run at all. Simple bar stock part, they can run 20 pcs before final buy off from inspection.

Where I work all machinists (10 of us and all CNC) do their own first part inspection. Everyone is responsible for their work. We do have a QC department that we take the parts to after we are done with the run.
It works at this company because everyone (well, almost ) knows what they are doing.

At the previous job, the setup person was responsible for checking the first part or two. We did not have a QC department there.

I'm all in favour of the person making the parts is able to do 1st article inspection themselves.

If the part is critical or expensive or both then I'd also advocate a double check by another person as even the best person can make a mistake. Both should sign off.

The "trick" is to make sure that any double check doesn't take longer than necessary so planning is important.

barbter said:

First Production shop I worked at had an Inspection dept that was the biggest dept in the company. The joke was that the kettle was always on.
A couple of quys used to play up challenging eachother who could keep machines waiting for the longest...

My place, we were a small shop. Less than 5 people (Tier 1 Aero, Defence, Sub Sea, Medical, and a bit of Commercial).
If the part was new, it would get a spot check by the guy who made it, and then 100% check by one of us 3 senior guys.

If the job was a repeat, we had colour coded prints on what features to check (if the 8mm cutter produced 3x features, check one 100% and the other 2 features would be correct).

All first offs were visually checked for tool miss-matches, with 100% check on any form cutters (or floor rads incase the wrong tool was put up), hole sizes (for drill runout), Internal threads (core and thread gauge and finish), and External threads 100% incase the wrong thread insert was used.

Click to expand...

I understand this mentality, but it isn't necessarily true. In practice, you would use a roughing tool and a finishing tool on everything (except maybe drills) so your 8mm finish endmill should finish everything, but sometimes you have limits on toolholders, # tools available in ATC, cheapy bosses, etc. So you have to 'double up' on using a tool to rough and finish or whatever, not to mention, it is possible your programmer made an oops and left stock on the floor of this feature, but not that feature.

Just my opinion, but it drove me freekin nuts when the other guy I worked with INSISTED if he used the same tool to finish 2-3-4 features, they would be perfect (relative) to each other.
Okkkaayy so material doesn't flex/move/distort, tools don't wear, models are 10000% infinitely perfect to the print (blah blah)