First post and first project!

What grade of stainless tube do you have? 304, 308, and 316 can be a bear to turn, as it work hardens just by looking at it. 303 is a free machining stainless that machines very nicely.

Let me guess: you get the carbide cutting tool up against the work and try to take a light cut. It initially cuts a little bit then stops cutting, correct? If so, that is work hardening.

The types of stainless that I mentioned as difficult to work require a rather aggressive cut. You have to start your cut at a good feed rate and depth of cut and keep going once you start. If you stop, the cutting stops, and the material work hardens. I used to work with 316 stainless all the time making various parts for mixing, bottling and packaging equipment. I learned in a hurry just how aggressive one needed to be to work with that stuff.
 
The method of setting on centre mentioned above in post 8 might present a risk of chipping carbide tools. Another quick and easy way to set on centre is to make a gauge like this:

IMG_0111.JPG
 
Ok, so could you explain how that works there @Tozguy ? Also i went back to my chunk of 304/apple coring project and really dug the carbide into it and engaged the drive quickly and it cut pretty easily with some lube on it . The work piece was definitely getting hot though.
 
Sure. The nuts and bolt are adjusted and locked so the underside of the bolt head is at centre height (i.e. on the spindle axis).
Then any tool can be adjusted upwards until the point just contacts the bolt head as in the picture. At that point the tool is on centre. A facing cut will prove if the gauge is correct or not. It is easy to adjust the nuts on the gauge to fine tune it. The bolt obviously needs to be cut short enough so only the nut sits on the cross slide.
It helps to face the underside of the bolt head first to get a nice flat surface. Also, when setting tool height the tool post should be loosened so the tool can be swung under the gauge.
Please let me know if its not clear.
 
I use a 6" machinist ruler most of the time. and have used a dead center in the head stock before also.
 
Never had an issue with chipping a carbide cutter using the ruler trick. That gauge looks like a good idea too.
 
So i cut my first threads today! I installed the change gears for a 1.5 metric thread pitch and went by a tubal cain youtube video for instructions. Well his method didnt quite work for me so i used a video from ox tool and managed to cut the correct pitch on the piece i had already ruined. So with me confidence ramped up, i remade the cap i had already made and cut the threads into it. Cap is just a hair undersized as its an off size to begin with (31.5mm) but it screwed in and snugged up nicely. Also got my first shot at knurling and it turned out pretty decent after i read about adding more pressure to imprint the metal.
 
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