If you use Threads, I'd like your opinion

[J-G]

'If you use threads' may seem an odd question on a metalworking forum but I try not to be presumptuous!

As an exercise in trigonometry and maths I’ve written a computer program to determine the readings that should be directly observed when measuring the Effective Diameter of threads using the ‘Three Wire Method’. Initially concerned with Whitworth, Unified, B.A. & Metric forms but expanded to include ACME, Buttress and other forms as well. Under consultation with two forum contributors, this grew somewhat to include details of ‘Standard’ thread series enabling not only selection but ‘comparison’.

Working in isolation can lead to unforseen consequences due to a potential narrow outlook and I’m certainly not immune from thinking that my way is the only way. Whilst I do have technical knowledge of threads/threading gained during my past career and now as a hobbyist, it would be useful to have the opinion of people who are still very much ‘hands-on’ as to how useful this program might be - or indeed whether it would benefit from further expansion.

If you would like to review the program - written for ‘Windows’ but currently also being evaluated under ‘Wine’ on Linux - send me a PM with your full name & e-mail address and I’ll make a personal copy available for you to download.

 

[Lorenzl]

A useful tool I used to use were "thread wires" basically a small spring with a small aluminium plate at either end. It was easier than pins as you didn't have to try and hold all the pins together at the same time.

Search the web for o-vee wire gauge

 

[deema]

Sounds brilliant, and extremely useful. Well done for putting all the effort into creating this. I’d love a copy…….a mobile app for Apple would be my only suggestion, message sent

 

[J-G]

A useful tool I used to use were "thread wires" basically a small spring with a small aluminium plate at either end. It was easier than pins as you didn't have to try and hold all the pins together at the same time.

Search the web for o-vee wire gauge

I am familiar with what I think you are describing @Lorenzl. Mitutoyo were the first to make them available I believe, but my program isn't concerned with the physical methods used, just with what measurements should be seen - ie. read from the Mic.

It also takes care of the fact that not everyone will have a full set of 'wires' so will calculate the figure to suit whatever is available and cover 'special' threads.

 

[Gerry]

I wrote a similar tool using an excel vba form about 10 years ago. It was aimed at metric threads. You entered the pitch you were measuring then the pitch diameters for the Go/NoGo. Measured the threads with Mic/Wires and enterd the measurements. It then automatically calculated whether it was in tolerance and gave a pass or fail and generated a small text report which I could save in the calibration database (Gagepack)

Gerry

 

[Sandyn]

I often have the need to measure unknown threads from old machines. This could be very useful. Message sent

 

[J-G]

That might be an 'iterative' process Sandy but certainly do-able.

Program made available.

 

[J-G]

@Gerry - My program reports the Max and Min figures that should be read from the Mic. for the thread to be in tolerance - essentially the opposite of your aproach. Both valid of course.

 

[J-G]

a mobile app for Apple

Aaaaagh! Apple

Sorry Deema, not a fan -- and I haven't yet tried to develop 'Apps'.

 

[Gerry]

@Gerry - My program reports the Max and Min figures that should be read from the Mic. for the thread to be in tolerance - essentially the opposite of your aproach. Both valid of course.

Yes this did that too as well as showing the formula for working out the threads measurement along with the wire diameter required and what tolerance band i.e G,H etc.
It was a geat calibration tool that wiped hours of needless and tedious calculation from my day. Especially useful when I had a few dozen thread gauges to calibrate and catalogue.

Gerry

 

[J-G]

Yes this did that too as well as showing the formula for working out the threads measurement along with the wire diameter required and what tolerance band i.e G,H etc.

I also account for 'Tolerance Class' and even the (often miniscule) effect of the Helix/Lead angle which does become important with multi-start threads - also covered.