I have a 12x37 sold by Smithy. The mechanicals are identical to the HF and Griz 12x36 but the electricals are somewhat different. The 12x36 machines have four lights/controls on the control panel while the Smithy has three - power on light, inching button, and on-off reset knob. Also the indicators/controls are vertical on the left side of the panel rather than horizontal in the middle of the panel. The spindle on the Griz extends past the surface of the cover for the motor pulleys/threading gear case making it easier to fit a spider for working on gun barrels, etc. I had an HF 12x36 that I did a major cleanup/minor restoration on a couple years back then sold to buy a new Smithy. Shop Fox also has a manual online as do others. The Smithy manual is sadly lacking compared to the others but they are all usable. I haven't looked into the internals of the various electricals.