I cannot seem to make them work. I am talking about these kinds of things: https://www.amazon.co.uk/dp/B00OPQZ2A8?ref=ppx_yo2ov_dt_b_fed_asin_title This is the second one I have had and have similar problems. I need one for adjustable diameter pencils as some of mine, especialy charcoal ones, are too thick for normal sharpeners. So I use it by just sticking the pencil in and turning the handle on the back. The first one I had had adjustable settings for thin and thick, I tried both. I hold the pencil so it doesn't rotate as I turn the handle. The result always seems to be the tip of the pencil gets cut off and the "base" of the tip gets sharpend. So the pencil ends up with a broad flat head. Can anybody tell what I am doing wrong? Does anybody know of any good sharpeners that take pencils of any size that work? Please and thank you of course :)