My mention of 1 1/2" was only a nod to the topic police. I know we're on another planet now.
The discussion about spin grinding and truing cone shaped reels merits a plug for becoming expert at adjusting the reel-to-bedkife evenly from side to side. Even small differences caused by someone with one hand much stronger than the other and an undeveloped sense of touch can, with daily adjustments, quickly cause reels to get pretty far out of shape.
Thank you for the explanation of how the rear drive works on the McLane, greendoctor. I am sure the modifications you are making will, as you say, make the machine track much better. I am having trouble understanding how or why HOC adjustments will be made via both the front and rear roller. Is that so that you will have a greater overall range of available HOC? I have only ever set height on machines where the rear roller is fixed. It can be difficult enough, sometimes, matching height from one side of the front roller to the other. I used to explain it as being like a bad haircut where one side gets cut too short, then the other side can only get fixed by making it too short, back and forth etc. With the roller adjustment at least you can keep adjusting back and forth without actually cutting anything too sort - but some days if you've had too much coffee or are thinking about something else it can take a few minutes.