I have had my Eriksen 180NE lathe for a few years and today I had a testing day........in all senses of the word.

I have been making a mandrel to hold some sack truck nylon wheels that I need to take 4mm off the OD (for my machine trollies). This required me to try threading for the first time!!!

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The first pic shows the lever position plate for various metric threads and the next 2 show the levers I have available (note these are not necessarily still in the positions I threaded in). The one labelled 'Reverse Gear' doesn't actually say which position is reverse and I nearly had an expensive crash with it being in left hand thread position!!

I need to create a thread for an M20 nut which is a 2.0mm thread pitch. Now the fourth column in the lever position plate deals with Metric threads and as far as I can read it for 2mm I need;
Spring Lever in 1
Lever I in B (as at the time I was using a speed requiring the speed lever in 1:1)
Lever II in Lead Screw
Lever III in Metric

Didn't get the result I wanted. This gave me a 4.0mm thread. I tried various other setting as below using a slightly higher speed and CML 4:1 (I have no idea what NML and CML mean but they are related to the speed controls);

NML 4:1
B1 = 3.5mm (should be 8)
B10 = 0.875mm (should be 14)
D1 = 0.875mm (should be 2)
D10 = 3.5mm (correct!!!)
A10 = 8.0mm (should be 28)
C10 = 2.0mm (should be 7)

None of this matches what I expected! If I move the lever Course Pitch-Normal Pitch to course I got some super big threads that had the carriage moving so quick I did not pursue using that setting.

Am I reading the dials wrong???????
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