Upgrade Kit, Mini Mill

Do not buy this milling machine upgrade kit if you have a HiTorque Mini Mill. Most or all of these features are already included on the HiTorque mills.

This mini mill kit provides an easy-to-install alternative to the noisy and fragile factory-installed gears that drive the spindle on the machine. The kit includes one belt. Change speeds without any tools. Simply remove the guard, loosen the lever locks and move the belt from one pair of pulleys to the other. Low speed range is 0-1700 RPM. High speed range is 0-4300 RPM.

The small pulley has a 9 mm bore with a 3 mm keyway. The large pulley has a 30 mm bore with a 5 mm keyway. If your shafts don't match these values, then this belt drive will not fit your mill.

Convert torsion spring mini mills to air spring. This mini mill kit provides all the parts required to change to a vertical air spring that mounts inside and above the column. With the air spring installed, you can move the mill head up until the top of the casting is almost flush with the top of the column. You can move it down until it almost contacts the adjustable Z-axis stop set in its lowest position. This air spring has about 35 pounds of force. This is not enough to totally support the head, but it is a heck of a lot more support than the torsion arm provides.

Here's a photo of the belt drive installed on a mini mill.

The belt drive increases the spindle speed significantly. This is great for small cutters that want to turn fast. However, it decreases the torque in inverse proportion to the speed increase. So, you won't be able to drill holes as large as with a geared mini mill.

Here is a review of the belt drive.

Here's a video by Red Beard Ops showing the installation of the belt drive conversion kit.

Here is another video that shows how easy it is to install the belt drive.

Part 2 on an installation video.

This product was designed for machines manufactured by SIEG, including those listed below. We have added compatibility for other non-SIEG machines when a “fit” can be verified.

If your machine is not listed, we cannot verify compatibility but encourage you to contact us. With additional information we may be able to help you find a solution.

• Bolton XJ-9510 Mill/Drill
• Clarke CMD300 Milling Drilling Machine
• Grizzly G8689 Mini Milling Machine
• Hare & Forbes HM-10 Mill/Drill
• Princess Auto 8507667 Powerfist Mini Mill
• SIEG X2-MT3 Mini Mill
• Micro-Mark 82573 MicroLux Milling Machine
• BusyBee CX605 Craftex Mini Mill
• Cummins (Tools Now) 7877 Mini Mill
• Eastwood 32498 Mini Mill
• Harbor Freight 44991 Central Machinery Mill/Drill
• Homier 03947 Speedway Mini Mill
• King Canada KC-15VS King Industrial Mini Mill
• Northern Tool 49657 KLUTCH Mini Mill
• Penn Tool Co XJ-9510-1 Precise Mini Mill
• SIEG X2-R8 Mini Mill
• Travers Tools OT2213 OTMT Mini Mill
• SIEG X2P Mini Mill
• LittleMachineShop.com 4962 SIEG Mini Mill
• SIEG X2D Mini Mill
• SIEG X2L Mini Mill
• WEN 33013 WEN Mini Mill

• BusyBee CX705 Craftex Lathe Mill Combo
• Grizzly G0516 Lathe Mill Combo
• SIEG M6 Multi-purpose Machine

• 2560 Belt Drive Kit
• Air Spring Kit Economy