Hi Frederick,
I have corrected the thread length issue and updated the Zip file in first post.
Please be aware that the thread length should always finish short of the screw length
else you will run the thread into the head.
Cap Screws and Button head screws are measure under the head but Countersunk Head Screws
are measured including the head so allowance for that is needed when setting the thread length.
I will look at adding a safeguard if possible.
Cheers
Barry