I know how I made my first mistake when trying to use the compound set to the 29.5 deg angle. I read the scale on the compound and overlooked the axis which was the reference for the angle. I expect I am not the only person falling for this mistake. My Grizzly lathe made it easier to fall into this trap.
In this picture I have moved the compound to have the scribe mark at the 30 deg mark. On my G9249 lathe, the only number shown is 0 (zero). The marks go up to 55 deg either side of 0.
View attachment 228260
After making some bad threads I also changed to using the carriage. I later realised my mistake was setting the angle to the wrong 30 deg, as in 30 deg from parallel to the lathe bed. It needed to be 30 deg from perpendicular to the lathe bed, or the face of the chuck. Easy mistake for a woodworker just starting out on a metal lathe.
I have a decent mitre gauge for the table saw so I cut a block of wood to 29.5 deg.
View attachment 228261
I glued a small magnet into the wood so it holds to the side of the compound.
View attachment 228262
I do not understand why Grizzly did not have the scale going to 60 deg. My lathe needs an angle block in order to set angles less than 35 deg (or 55 deg) depending on how the angle is defined.
View attachment 228263
Interesting post earlier discussing the potential origin of 29.5 deg angle. It is easier to use the carriage.