ernie conover turning videos

Yup. And if you go a tad undersized, you can "recover" by putting a paper towel between the chuck and bowl. I learned that off a Raffan video. It's always good to have the tailstock engaged of course, until the very last...

I generally use the stub of whatever is left over after parting off the turning.

Graham

i got the feeling in the conover video that he always got it right but may be due to video editing

but really i think it is a good trick to use a towel and it depends on what you are turning

he did not use the tailstock as it was a toy top

not sure if we are talking about the same thing

the jam chuck example i saw was a small toy top jammed into a hole in a chucked piece are you talking about jamming between head and tail

Often, when people turn things like boxes, the stub left over after parting off makes a good jam fit chuck. In that case you would cut the tenon on the stub so that the piece fits over it, rather than into a hole.

Other times, it makes sense to turn a recess in the jam fit chuck and put the piece into the hole as you describe. It just sort of varies with the application. The idea is essentially a friction fit, either holding on the inside or the outside of the piece depending on what would give the best grip...

...Kevin

If, for example, it's a box turned in endgrain, when I part off the lower part of the box, I turn a hole in the stub left in the chuck and jam the top of that part into the hole so that I can finish the base and remove all signs of the parting off. Graham

makes sense i will have to try it out

i did something sort of like this out of need

i made a spindle with a morse taper on both ends one jammed into the headstock the other i put a piece of pvc pipe over and turned a length of pvc pipe

my tailstock needed no mods and worked as is into the other pvc end i use this same setup just to sand copper pipe on the lathe to a nice shine

i need to get better at removing the parting marks on pieces

it makes the end product much nicer