Dry or wet sanding?
Do not use a dry grinding machine to sharpen your good chisels and plane blades made of carbon steel. The heat generated leads to a loss of hardness, significantly reducing the service life. It is a common misconception that this does not happen if you remove the blade from the rapidly rotating grinding wheel just in time, before it turns blue, and dip it in water. A structural transformation occurs at significantly lower temperatures. You cannot control this process. Complaints about supposedly poor steel quality of blades, whose good quality I was aware of, were always due to treatment with dry grinding machines. Slow-running wet grinding machines (about 90 to 120 revolutions per minute) prevent heat generation. They grind slower than dry grinding machines, but you are guaranteed good treatment of your tools. The best available on the market are based on a sophisticated system and are manufactured by the company TORMEK in Sweden. However, the acquisition costs exceed many budgets. With good sharpening stones, a sharpening guide, and some practice, you can achieve the very best results. When sharpening by hand, you get to know your tool best and are independent of the usually stationary machine. Moreover, a grinding machine is of no use to you if you want to flatten the mirror side of your plane blade. For that, you need a flat surface that a round-running machine cannot provide.
There are differing opinions on whether the bevel of a blade should be ground hollow, as with machine grinding, or better flat, as with hand grinding on the sharpening stone. The hollow grind makes subsequent honing easier, but the resulting sharper angle weakens the edge and makes it more susceptible to chipping. This is particularly negatively noticeable with the very hard laminated Japanese blades. In Japan, it is unthinkable to grind the bevel of a plane blade hollow. The grinding recommendation for plane blades from the manufacturer E.C.E. clearly opposes hollow grinding. Therefore, if you choose a flat bevel for your plane blades or chisels, you are in excellent company.