I had a big surprise this past Saturday from my Logan lathe.
I was going to finally finish another long "Round-tuit" project. It's another Guy Lautard project, a
"finger plate". All I need to do was make the rocker clamp and the 5/16-18 threaded post used to
clamp down the "finger".
For the newer memebers who have never heard this term or of this tool, here;s what it looks like.

I was going to finish it up by making the 5/16-18 clamp rod in the center of the tool. Guy suggested
using a ready rod. I didn't have that size or a die to make one so I decided I'd single point it using the
Logan lathe. I set up the tool put the levers in ther proper place on the quick change gear box and
took a light cut to make sure I had the right number of threads per inch. Imagine my surprise when I
counted 20 threads instead of 18. Yet the lever was in the right hole for 18 threads. It does go into
the hole a bit hard ever since I got the lathe. I quickly checked to see if it would cut a 16 thread. Which
is on the left of the 18 thread and then on the 20 hole for a 20 thread per inch. They were fine. So what
was going on.
To make a long story shorter,I decided to remove the gear box and check the gears.
Here's a diagram to help better understand what's inside a QC box.

The left lever selects the letter and the right lever picks the actual thread. So if the left lever is in the "B"
position and the right lever is in the 18 postion you will be using the gear that I've marked "wrong gear"
and hopefully cut an 18 threads per inch thread. Since that gear is the same size as the one to the right of it,
it cut a 20 threads per inch.
I wrote about my plight on the Model Engineering list I belong to and Scott Logan of Logan Actuator Co. is
a memeber. He e-mailed me back said he had one in stock. I recieved an order forum and will be sending out
the order Monday.
I think what happened was that the lathe got rebuilt at one point in time and somebody put the wrong gear on.
Scott even said that it would have never left the factory like that. He also provided me with a bit of info. The lathe
left the factory on May 28, 1971 and was sold to Falk Mill Supply in Rochester New York. It's nice knowing a bit
of history behind the lathe.
So now I'm without a larger lathe for a while. Guess it's back to using the Sherline lathe to make some small parts
for the up coming project.
Bernd