Being able to turn a knob and dial in a higher or lower speed rather than moving a belt and changing pulleys has become almost a necessity - for me. Being able to dial down the rpms for a very delicate cut or to clean up a narrow deep V now seems crazy at higher rpms. I'm still playing in the lowest rpm range on the JET mini/midi .
Being able to turn the lathe on and off without having to pull the tool away to get to the on/off switch has become a necessity - for me. There are delicate cuts that must end with the cutting edge at a specific point, and tool orientation which I formerly blew often pulling the tool away.
A long goose neck lamp that puts light right where I need it, yet shields my eyes from the bulb has become a necessity - for me (and will no doubt require a higher watt bulb as my vision goes).
An MT jacobs chuck for the tail stock makes drilling, either with a forstner bit or brad point bit, beats TRYING to drill a hole in the end of a turned piece on a drill press - and therefore has become a necessity
- for me.
Turning a tenon on the end of a finial that must fit a hole in the lid of a turned box - when you can't fit the tenon to the hole while the finial is on the lathe - necessitates a dial caliper - a digital dial caliper.
Having a decent scroll chuck - and several sets of jaws has become a necessity - for me. The possibilities it/they opened up changed not only what I can do, but how I can do it. Definitely THE lathe accessory.
Have you got an "accessory" you didn't know you had to have until you had it and used it? Why?
charlie b