Are spindle adapters safe?

I tried using a vice and strap wrench but hadn't thought of a sharp impact. Thanks for the tip. It's kind of moot now because the older lathe is used rarely, and only for spindle work. I think I will give it a try though just to get the sattisfaction of finally freeing it.

if that doesn't work, use a clamp to squeeze the Vbelt together to lock the spindle (dont' use the spindle lock or indexing pin for risk of damage) and repeat the impact process - if you can hit it right, one hard smack ought to do it.