Untitled Gardening Project: Aside

The Sieg x1 'Micromill' uses a nylon geartrain between the motor and spindle. The nylon gears are supposedly prone to breakage although I've not broken any myself. The gear train is not particularly well balanced, it's noisy, and it gets noisier as it wears.

The gearbox provides two speed ranges selectable by a fork and knob mechanism. The high range spans roughly 0-2000 RPM. The low range of 0-1000 RPM is provided presumably to run larger endmills at higher torque without stressing the gears. The motor and controller appear more than capable at providing high torque at very low RPM.

A belt drive solves the noise and gear breakage problems. A multi-step pulley also expands the range of possible spindle speeds, in this case to 8000 RRM. When a belt wears out, it's easy to replace.

When I bought the micromill a year ago, I had also ordered a belt drive for it. The belt drive I selected [like many other add-ons for hobbyist machine tools] are made by another hobbyist and I don't think he quite realized how popular his little kits would be. I ordered my kit in October 2006, about a month or two after he began offering them. Last Thursday, it finally arrived... ten months later.

The belt drive kit replaces the mill gearbox entirely. The motor controller is normally housed in the gearbox, and so it has to be relocated to a new enclosure.