Author Topic: "Senior moment"  (Read 1888 times)

Offline scc

  • Full Member
  • ****
  • Posts: 431
  • Lancashire, UK
"Senior moment"
« on: April 13, 2017, 08:42:23 PM »
Started on the water pick-up casting for my Burrell.  Set up in 4jaw, do all internal stuff,  get out "Zeus" thread book and check o/d for 3/4 bsp, machine casting to 1.041 in. Go for dinner...return to shop and check book for TPI and set up change wheels to suit. Cut good thread then notice my 3/4 bsp tap for the nut is 14tpi :noidea: I have just cut 10tpi on the casting having read for 3/4bsw on the adjacent page :facepalm:   What a good job I have to make the nut as well,,,,,no one will ever notice :naughty:

         You all have a good Easter                      Terry

Offline crueby

  • Full Member
  • *****
  • Posts: 6614
  • Rochester NY
Re: "Senior moment"
« Reply #1 on: April 13, 2017, 09:15:07 PM »
It's always satisfying to make something precisely, perfectly wrong!

Offline gerritv

  • Full Member
  • ****
  • Posts: 446
  • St Catharines, ON
    • Gerrit's Hobbies
Re: "Senior moment"
« Reply #2 on: April 13, 2017, 10:04:41 PM »
Yet another advantage to single point threading, made to fit :-)

I recently cut several 1/2-40 and 5/16-40 ME internal and external threads, all at 60 because I only realized later on it was supposed to be 55. Fit great of course.

Don't confuse activity with progress

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12042
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: "Senior moment"
« Reply #3 on: April 13, 2017, 10:42:58 PM »
Easter Bunny poop happens. At least you can recover from it though. My last faux pas was unrecoverable.


Offline PJPickard

  • Full Member
  • ****
  • Posts: 102
Re: "Senior moment"
« Reply #4 on: April 14, 2017, 01:52:29 AM »
Since I teach a lot of engineering students...many learn the "making something perfectly wrong" thing the hard way. We all did(do) ;)

Offline Art K

  • Full Member
  • ****
  • Posts: 856
  • Madison, Wisconsin USA
Re: "Senior moment"
« Reply #5 on: April 14, 2017, 03:55:28 AM »
You didn't have anything more important to do anyways, right? :mischief: And you've always wanted to do an internal thread. I recall that in tech school I had to make an acme bolt and then the nut to fit it. Still have it laying around.

Offline derekwarner_decoy

  • Full Member
  • ****
  • Posts: 391
  • Wollongong ...... Australia
Re: "Senior moment"
« Reply #6 on: April 14, 2017, 04:29:24 AM »
Yes Art K...even in Australia...the same test in 3rd year mechanical trade apprentices  :smokin2: in the early 70's

The thread form was represent a bench vice screw......about 1" diameter....Steel Grade not remembered   :facepalm:

The nut was an irregular rectangular casting of good quality Cast Iron

An amusing check was the angular displacement [wobble] of the nut on the threaded shaft..... :lolb:

Derek Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia

Offline mikemill

  • Full Member
  • ****
  • Posts: 253
Re: "Senior moment"
« Reply #7 on: April 14, 2017, 09:42:35 AM »
The sign of a good engineer is  knowing how to get out of a cock up so no one will ever know!!! We have all been there.