Watching the video on the latest LiDL (again) on line offers I got to wondering if the cheapy chainsaw sharpener could be easily modified to do basic toolbit shaping. Looks to me that suitable carriers could easily be fabricated to present the toolbit at appropriate angles enabling it to be cut off close to the desired shape. Then only a light touch on a fine grinding wheel whould be needed to get a nice sharp edge at the correct angles. Probably too much to hope that the finish would be good enough to need only honing.
Obviously the basic clearance angles cut would need to be a little excessive so the final sharpening grind can be quite shallow realtive to the depth of the tool.
I have a Clarkson T&C grinder which is pants at major bit shaping but will do a wonderous job at the final sharpening grind. I don't much care for the amount of abrasive mess thrown off by the coarse wheel on the double ender grinder when rough shaping and, frankly, there are better things to hang on the grinder than the rough wheel.
Clive