3 roller grain mill build question

[sourmash]

I am in the middle of a grain mill build and have the rollers done and ready for the sides to be drilled for bushings etc... Looking at the large MM 3 roller mill, I am curious for those who own the mill does the bottom roller rotate in one direction or does it occasionally rotate in either direction?
Without a gear drive and an idler in between the drive and the driven, the bottom roller can rotate in either direction. Just curious why the bottom roller is not geared in some fashion to dictate the direction of rotation?

 

[Randar]

I have an MM3 and haven't looked when milling, but my gut feel is that since the drive roller is generating the torque and will be generating the most force against the bottom mill (via the grains passing through), that it will always rotate in the opposite direction of the driver roller. For example, the drive roller is going clockwise and both of the other 2 rollers will go counter-clockwise.

Hopefully someone can confirm this for you though, as it is just my intuition (so grain of salt required!)

 

[Catt22]

The two top rollers rotate in opposite directions. The bottom roller rotates in the opposite direction of the drive roller above. Because the bottom roller is rotating in the same direction as the non-driven roller above, the grain can only get pulled in between it and the drive roller. The bottom roller can only rotate in the opposite direction from the drive roller. The friction of the grain between the rollers is what causes the bottom roller to rotate. I think that the rollers are not gear driven in order to simplify the design an to reduce costs. It could be done, but it's not necessary.

 

[sourmash]

Its only been 10 months since I started this project and its done!
This is the 3rd revision and it finally has enough power. Started out with a belt drive with a double reduction gear box off of a 1/8HP motor. Soon as the grain hit the rollers it would stop the drive cold. Then came the 1/4 HP bolted to the same DRGB and again stopped it cold. That was enough ***** footing around and then went to a 3/4HP motor DRGB with chain drive. With the correct sprockets on the drive roller speed is 68 rpm. I haven't done a pound per minute test yet but lets just say it doesn't waste anytime. The rollers are 13 1/2" long cold rolled with the bottom roller on an elliptical bore to adjust the crush.

 

[camiller]

Nice. Especially Like the warning sign.

 

[tankdeer]

So where's the DIY?