If you crack your own grains (and I recommend you do- see my opinion why), here are a couple of tidbits I’ll pass on that I learned the hard way. They both have to do with roller adjustment. When I first got my grain mill, the instructions suggested getting a set of feeler gauges to set/adjust the roller gap to, in order to define your grain crush. I thought this was a superfluous detail and I would just eyeball it. I found after my first setting was too large that it was actually quite hard to tell by eye if the gap was the right size to crack the barley husk without pulverizing it to dust.
Really the only way to tell was to run a batch of grains through and look at what was coming out the other side. If too much or not enough, adjust accordingly. Making these adjustments by eye was quite tedious as I would continually overshoot or undershoot my mark. In the end, my efforts to try to simplify things by skipping the feeler gauges was actually making it harder for me. So I bought a set and figured out what seemed to be the right setting.
In the process of these adjustments, I got burned by the lock nuts on the adjustable roller. The mill was set up with a dial on both ends of one roller to dial it in closer or further away from the other roller. Then it had two locking screws to turn in tight to keep the roller in position. Stupidly, these locking screws have a nut threaded onto them, that cause you to bottom out your tightening screw against the nut and not actually be locking the roller into position. I found this out after seeing a batch of kernels go through and not actually get crushed properly.
I have no idea the intended purpose of these nuts. I had initially thought they were to keep your adjustment screws from backing out once you locked them in, but that’s not the case. They way they’re set up, they only function to prevent you from fully locking your adjustable roller into place, but don’t prevent your roller from backing out and increasing the gap as you grind. So word of advice, just back these nuts way off and get them out of your way so you don’t get burned like I did.