These Gear Ratio Sets provides extra capability to the Sieg X3 and equivalent milling machines, such as the Grizzly G0463,

These mills are very weak at low rpm and sometimes have trouble even turning consistently unless the rpm is over 400. In one configuration, this set acts as a higher ratio gear to boost torque from 0-700 RPM spindle speed, peaking at a 40% increase at 600 RPM.

Flip the gears to run a much lower ratio to get a theoretical rpm limit of 8600, which we do not recommend be used unless the entire spindle assembly has been upgraded.

The combination of these and the stock pulleys (in stock configuration and flipped), give the ability to greatly increase the torque at most RPM. (Such as an average of 15% more power than reversing the stock pulleys from 2700-4300. See the chart for power comparisons with the different setups.

There are two options for this kit: A large Aluminum and small Steel pulley kit or with Carbon Fiber filled Nylon pulleys. Each kit uses slightly different sets of spacers and are priced differently according to manufacturing costs. Both styles have proven to run great on customer's machines. It simply is up to ones preference as we always try to give as many options as possible.

These kits come with a spacer and key for making the stock-switched gear setup be more evenly aligned. They also includes two different pulleys that are easily swappable, all spacers and keys needed, a gates belt, custom wing bolts for quick removal of the main cover, and a vinyl sticker to show what gearing is ideal for any RPM.

Once performing the swap a few times, it can be done in about 5 minutes. It makes this great little machine more capable by having the options of more low end torque, higher RPM than stock, and more power at many points in between.

We also made a number of other modifications / improvements to these mills, as they have been a great hobby mill for countless people. Please check them out here Sieg X3 Page.