For the first time in my life I had to re-tip m own cue I have had the same Pool Cue Stick for about 5 years and while I was shooting the pool cue tip fell off. I figured how hard could it be so I went to a pool cue store bought the right size 12mm tip and sanded both the cue top, and the back of the tip down and layed it flat. squeezed some super glue on the base then put the tip on while using rubber bands and a clamp to keep it down, flush, and straight and waited for 24 hours.
I went to go play som 8 ball pool the next day and it after an hour of playing I realized I was missing most of the easy straight in shots and especially all of my cut shots. So I sanded the tip down to what I thought was flat again by hand… This was the worst experience in my life and one of the guys who sells and take care of my cues told me that what I did was the worst thing possible. He took my cue shaft away from me and stuck it in a pool cue machine and sanded the tip off, then with the same machine routed the shaft top down a good millimeter, glued on a new tip then sanded the tip down straight in less than 1 hour after that my cue was perfect just needed to wait 4 hours for it to be completely dry and was good to go.
What happened was when I put on my own tip there is no possible way any human or person can find the exact level like a real tipping machine could do, plus as the shaft would spin in the machine it would not only make everything level automatically but would also curve your tip evenly down. I have been playing pool for over 18 years and now I have learned my lesson. You have 2 choices when your pool cue tip is non-functional or snapped off. Buy a brand new shaft for your pool cue stick or take it to a professional with the same leveling machine, never let someone eyeball it on or think its an easy fix in the long run you will be a much happy camper.