I have turned more acrylic then I would like to say...experienced so much over the years, chipping, breaking issues have always pointed to two things...too much force applied to the piece from the chisel...wrong parallel height with the cutting edge of the tool and the center line of the work piece. Always take your time....you are not in a race...patience is key to turning acrylic. Even parallel cuts across the length is so critical ... also check your height of the contact point of the chisel to your center line of the work piece. I set mine to less then .010" below the center...and this will change as the piece's diameter lessens, so you will also change you tool rest height accordingly. We all know the importance of sharp tools, I polish mine that I turn acrylic with...why? ... less friction means less heat....even if you are careful about pressure applied rough sharpened tools will create more friction and grabbing opportunities. One thing that needs to be said....round nose scrapers say 3/4" .... are perfect for turning acrylic (after you have turned the square to a cylinder) using a spindle gouge to turn from square to cylinder is fine....but...with me I prefer the scraper to the gouge after the initial cylinder is formed. Also I take a create a reverse bevel on top of my scrapers for discharge of material coming off of the acrylic, this keeps the piece cooler during turning...I hope this helps...pappy
