No, I have not. Attempting to grind in a taper to the correct angle requires a piece of equipment that I do not have. Although it looks like all you have to do is mount a Dremel tool to a cross slide with some string and duct tape and grind away using a lot of trial and error, you will find out that that approach really sucks. Companies that produce spindles run thousands of them on expensive heavy machines. The only way I know to correctly set in a high precision taper is with a sine plate and punch grinder. The taper can then be set in to a standard by readjusting in 1/10,000 inch increments. You can get taper attachments for a lathe or try to tap in the compound rest but for a spindle that should have a tolerance to better than .0001 inches it is a crude solution at best.