As an engineer with a background in kinetic energy, it has been my experience from commenting on this several times in the past is that folks don't want to hear somebody saying that their favorite piece of safety gear doesn't provide the degree of protection that they would like to believe that it does. What seems so obvious to me may not necessarily seem that way to most people. Read the information that comes with the 3M Tekk Professional Faceshield and we discover that it also requires the user to wear safety goggles or glasses with side shields ... at least in an industrial environment. We also see that the type of protection it provides is against small high speed particles that have very low kinetic energy. From actual experience most of us would also say that it does an good job against flying bark chunks when we start roughing out a piece of log. There's something about the chunks of bark that most of us haven't considered -- at that stage of the turning process, we are probably running the lathe at a fairly slow speed. The kinetic energy contained in a moving object is the product of mass and velocity squared (in other words, KE = m Â· v[SUP]2[/SUP], in vector notation). Two examples in layman's terms: Doubling the mass while keeping the velocity constant doubles the kinetic energy. This sounds intuitive to most of us. Doubling the velocity while keeping the mass constant quadruples the kinetic energy. This is the part that may come as a surprise to most of us. Suppose that we start roughing out our split log at 300 RPM and pieces of bark, wood, bugs, and sap are impacting the faceshield and we are very happy that the faceshield is doing its job. Suppose that we get in a hurry and decide to crank the speed up to 600 RPM. Now everything flying at us has four times as much kinetic energy. We might feel like we got caught in a hailstorm. But, what if we got in a really big hurry and cranked the speed up to 1200 RPM? Well, now each chunk of bark and other stuff has sixteen times as much kinetic energy as when we were turning at 300 RPM. Those little pieces of bark are probably starting to hurt. Will it be enough to knock your faceshield cattywompus if not completely off? I'll let somebody else try it. Well, heck 1200 RPM isn't too fast ... suppose that we are hell bent for leather to finish this turning and crank the speed up to 2400 RPM? Good idea, while ducking for cover, I'll just mention that each chunk of bark now has sixty-four times as much energy as when turning at 300 RPM. Al mentioned getting hit [in the faceshield] by a one pound piece of wood: Stating the mass without mentioning velocity tells us nothing about the kinetic energy, but I would bet that even at slow velocity you are likely to get a broken nose and a nice purple bruise ... maybe even a mild concussion. Mass really does matter and, of course, velocity is the killer. If we assume that a typical piece of bark weigh about an ounce, then at 300 RPM, the piece of wood would have 16 times as much KE as the bark. At 600 RPM, the piece of wood would have sixty-four times the KE of bark at 300 RPM. At 1200 RPM, the one pound piece of wood would have 256 times as much KE as the piece of bark at 300 RPM. And, at the insane speed of 2400 RPM, the piece of wood would have 1024 times as much KE as the piece of bark at 300 RPM. Looking at big numbers doesn't give us something that we can wrap our head around (I'm speaking figuratively), but we ought to at least recognize that we're talking about lots of energy -- far in excess of what the faceshield can handle without collapsing into our face. I have heard some people speculate that a faceshield distributes the impact over a wider area -- maybe if our face were shaped like a faceshield -- since it isn't, our human "crumple zone" would be the nose, teeth, cheekbones, and cranium. Pieces that come flying off the lathe generally aren't nicely shaped and smooth like the things that we turn -- they are usually jagged and have sharp edges. I like Odie's solution, but in any case, our heads wind up absorbing the energy of an impact. The nice thing about Odie's solution is that it has some mass and stiff cushioning that has the effect of distributing the total energy over a longer period of time. By spreading the energy out over a longer time, it is equivalent to a lower impulse of energy. I was turning a very large mesquite bowl about 16 inches in diameter when a piece that weighed about 8 ounces suddenly flew off. I think that I had about a half second of warning -- not enough time to do anything if I had been standing in the wrong place. It hit the brick wall behind me, bounced off and hit my truck about twenty feet away, flew back and bounced off the wall behind me again, and finally came to rest wedged under one of the tires of my truck. The piece had a scary resemblance to an axe head and was at least as sharp. I think that Rob's warning was spot on. It is very obvious that the Raygear is a horrible idea. Is the thing really certified or are they just blowing smoke? I think the latter. If the price wasn't so absurd, I would buy one just to see if it is as bad as it appears to be. I don't believe that Rob really said anything about "regular" faceshields other than implying they are much better than the Raygear and I would have to agree with that. I think that it was probably my previous post about faceshields, in general, that might have influenced your interpretation of what Rob said. So, blame me for sidetracking the discussion, but I don't think that I will apologize for opening this can of worms. Obviously, a better solution would be something that doesn't require us to use our heads to absorb the energy of an impact. The best solution that I have seen is the cage that comes with Powermatic lathes and that nobody uses. Maybe it is not the optimal design for the type of turning that we do (I think that the cage was probably designed with spindle turning in mind), but I am sure that something more user friendly could be designed that is anchored to the lathe and fits between the spinning wood and turner.