We continue to improve our thread detection capabilities. What are other companies using? What methods are cost-friendly while still being effective?

We continue to improve our thread detection capabilities. What are other companies using? What methods are cost-friendly while still being effective?

Hi mkbagwell,

What is "thread detection"? I have never heard this term before.

Hi mkbagwell,

What is "thread detection"? I have never heard this term before.

I used it to detect this thread. :tg:

are we talking about screw threads? Like detecting a drilled hole vs a drilled and tapped hole?

Wow. I'm surprised this term isn't as commonplace as I thought.

Yes, it's detecting whether or not threads have been tapped into a drilled hole; present or not present; threads vs. no threads.

We do it the old fashion way - visual inspection.

Not very cost effective - but we do a minimal of tap work.

At my working place, we keep a standards board of all the common fasteners that are used. At that phase, the QC inspector is required to pull the fastener off the board and fit test each threaded hole and sign it off as a step on the operation sheet.

Wow. I'm surprised this term isn't as commonplace as I thought.

Yes, it's detecting whether or not threads have been tapped into a drilled hole; present or not present; threads vs. no threads.

Is it fair to assume that your manufacturing processes are extremely high precision and high volume?

It it fair to assume that you are looking for experiences with machine vision in a high volume/fast production-type environment?

Stijloor.

Yes, both statements are true. Do you have some information you can share? Thanks.

Is it fair to assume that your manufacturing processes are extremely high precision and high volume?

It it fair to assume that you are looking for experiences with machine vision in a high volume/fast production-type environment?

Stijloor.

:agree1: what Siijloor says.... is it high volume and/or high precision?

We make threads all day long every day, but the volume isn't so high nor the process so automated that we can't do it manually. Also the capabilities we gone so far as to calculate show that sampling is acceptable.

Is it fair to assume that your manufacturing processes are extremely high precision and high volume?

It it fair to assume that you are looking for experiences with machine vision in a high volume/fast production-type environment?

Stijloor.

If that's the case, then I'm assuming that he's looking for these checks:

- Threads-per-inch count or pitch measurement.
- Visual inspection for burrs, slivers, stripping, upset thread, and drunken helix.
- Pitch diameter.
- Minor or root diameter.
- Lead.
- Thread angle and form.

In which case, a thread micrometer should be used or equivalent.

Another factor would come into play as whether the gage that would be used be considered a "working", "inspection", or a "master" gage tolerance, depending upon the intended application.

Thread gages are classified according to accuracy as W, X, and Y, with W being the most accurate. The dimensions and applicatins of each of these three classes of gages are covered in Machinery's Handbook, the National Bureau of Standards Handbook H28, Screw Thread Standards for Federal Services, and in ANSI B1.2, Screw Thread Gages and Gaging.

Mkbagwell, are you looking for a more efficient way to satisfy these checks?

The Company I used to work for did a lot of threaded holes. We did all of our threads on cnc drill ctrs. What we would do was check the 1st and then last hole of same part with thread gage for each tap that the machine was running. If threads were present; all other threads would be there. For this check we would use a standard bolt of same thread size because we were only checking for presence of threads. Our qc dept. would check the quality of the threads at a prescribed frequency during the production process and at all tap changes etc.. We did try a vision system but because of several "false" positive readings each shift we decided it wasn't worth the down time involved to investigate the process each time the vision system stopped production.

Tlonkey

We have a particular part that is threaded(internal) at a secondary operation. We had one part that was a missed operation. We are still seeking to implement a pokeyoke application over a year later!:mad:

If that's the case, then I'm assuming that he's looking for these checks:

- Threads-per-inch count or pitch measurement.
- Visual inspection for burrs, slivers, stripping, upset thread, and drunken helix.
- Pitch diameter.
- Minor or root diameter.
- Lead.
- Thread angle and form.

In which case, a thread micrometer should be used or equivalent.

Another factor would come into play as whether the gage that would be used be considered a "working", "inspection", or a "master" gage tolerance, depending upon the intended application.

Thread gages are classified according to accuracy as W, X, and Y, with W being the most accurate. The dimensions and applicatins of each of these three classes of gages are covered in Machinery's Handbook, the National Bureau of Standards Handbook H28, Screw Thread Standards for Federal Services, and in ANSI B1.2, Screw Thread Gages and Gaging.

Or is he simply looking for a detector that says whether it's a hole or threaded hole?

I assume it's that there is or is/not a thread in the hole. That is the most common type of thread defect. CNC and Screw machines are known for only partially threading or tool breakage that causes missing theads. My experiences with thread sensors are that they seem to fault out without an error, operators become numb to the alarms, and parts without threads get missed.

I assume it's that there is or is/not a thread in the hole. That is the most common type of thread defect. CNC and Screw machines are known for only partially threading or tool breakage that causes missing theads. My experiences with thread sensors are that they seem to fault out without an error, operators become numb to the alarms, and parts without threads get missed.


Good point!

We looked into 100% poka yoke detection for tapped holes.

The customer was unhappy with 3 PPM

We found things similar to this

http://www.newvistacorp.com/thread.htm

Be sitting down when you get a quote!

The big boss ended up telling the customer we would fly down and sort the 3 PPMs rather than spend the pile of money on this equipment.

Too bad, some of us wanted the new toy to play with...

We are looking at automated thread presence, non-invasive, without hard-gauging the tapped hole, a computer vision system or eddy current testing.

We are looking at automated thread presence, non-invasive, without hard-gauging the tapped hole, a computer vision system or eddy current testing.

We use both vision systems and eddy current.

Dave