Hi, Ralph,
The Gear Reduction unit itself includes just three gears; the pinion, an idler gear, and the gear/pulley that drives the belt.? The two larger gears shown in the photo were part of the threading setup that I didn't bother to remove for the photo.? Perhaps the photo below, taken a year or two after the GR unit was first installed, shows it more accurately.
Incidentally, since the mini-lathe can be electrically reversed, you would think that you could do away with the need for the idler gear, whose only function is to make sure that the belt drives in the right directly when the lathe is electrically set to "Forward".? With no idler, you could theoretically just reverse the labeling on the electrical "Forward/Reverse" switch and save the extra gear.? BUT... Real Bull lathes put a resistor in the circuit to reduce the lathe speed when running in reverse.? I don't know if that is true of Siegs, but it is with the Real Bull.? So the idler is necessary.
Also, you will notice the curved slots in the GR unit at the front of the motor.? These are for cooling, but are also used for setting the position of the GR unit before tightening the radial set screws.? You can see the three small screws going through the slots.? It is necessary to remove the front end cap from the motor and tap it for some small screws; I used 6-32, but M4 would also work fine.? As I understand it, Sieg lathes use a motor with a plastic front end cap, which cannot be reliably tapped, while the Real Bull end caps are metal.? For that reason, this gear reduction unit will work on Real Bull lathes, but not Siegs.? No matter, as there are numerous other gear reduction designs out there that work fine on the Sieg.? The point is to get the torque up there... this comes at the expense of top speed, but I have never been very comfortable spinning my 4-inch chuck at 2500 RPM anyway!
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Regards,
Charlie
New Jersey, USA
