I would have to go out and measure it but we use I believe the smallest flat belt pulley on the cub, to go slower, and we use a bigger one to go faster for the hammer mill. These don't need to run really fast. The #30 were stenciled with the words, Excessive Speeds are Dangerous and Destructive.
Be safe,
Russel Foster
What I've found, at least with my burr mill corn grinder, is that although the cub with the standard pulley will run it but it runs a little too fast to be practical. I have since put a 5 1/2" pulley, rather than the standard 9" pulley, on my ford 2n, which is also equipped with a sherman under drive trans that slows the PTO down even more. This has cured the problem and it runs more at the speed of a hit and miss engine which the mill was probably designed for. Changing the pulley on the cub and or the sheller and you might get it to run where you need it to be.
Kirk
I have found one like I posted the picture for what seems to be a good price. Do you know how to find out what the maximum rpm would be for the sheller?
I would guess on my pto I'm running some where around 240 but I don't know how high your can go on you sheller. Didn't cub make something to gear it down at the pto? Here's a reducer I used to have for one of my fords.
Kirk, The Hub City reducer/reverser slows the PTO to normal 540 rpms and changes the direction of rotation. I'm unaware of one for the Cub that slows it more (unless it would be the one for the Prewitt/Groshart post hole digger).