I am a first time poster to the chainsaw forum. I need some advice. My grandpa has sharpened chains on a chain grinder for as long as I can remember. He always sharpened my for free. He has done a great job up until this year they just don't cut like they should. I had 1 tank of gas on the chain and finally gave up. I took it off and went to the stihl dealer and he said the angle is off. My first problem is that my grandpal is 81 years old and has emphazima. He won't let go of his log splitter or chainsaws, he even keeps buying new saws. He can't even pull start any of them without being out of breath. He is having a hard time facing reality about being 81. If I go tell him that he is doing it wrong, I am afraid it will really bother him about being old. When I take my next chains down to get sharpened, what should I be looking for on the grinder? I am running a stihl ms390 with a 18" bar and a 3/8" chain. He has an old tecomec grinder and a brand new one that I carried in the basement and sat on the floor for him 2 years ago and its still sitting in the same place. Any advice on how to tell my grandpal that he is not getting them sharp and things that I can look for on his grinder as far as setting would be greatly apprecciated!