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Products > Kits > Mill Conversion Kits     All Heavy Metal CNC products

CNC Conversion Kit for Mini Mills

         Made in United States
CNC Conversion Kit for Mini Mills
Part Number: 6224
Weight: 12.0 lb

Price: $679.00

In stock
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  • Heavy Metal CNC kit
  • Fits all SIEG X2 mini mills shown on the Compatibility tab
  • 16 mm x 5 mm C7 ball screws
  • Thompson ball nuts for minimum backlash
  • NEMA 23 motor mounts


This kit provides the mechanical elements you need to convert a Mini Mill with a 220 mm x 100 mm table to CNC. It includes ball screws, ball screw nuts, thrust bearings, and motor mounts plus the fasteners you need to install them. It does not include motors, drivers, power supply, or software. See the Documents tab for the electronics and software you will need in addition to this kit.

The ball screws are 16 mm diameter and 5 mm pitch, C7 grade with a tolerance of 30 microns over 300 mm.

All aluminum parts are clear anodized for corrosion and scratch resistance.

This kit is designed to be adjustable to any and all of the machines shown on the compatibility tab. Sometimes it just isn't possible. Because of manufacturing tolerances, there is variation from machine to machine. When installing the kit you may need to make some modifications not listed in the instructions.

Chris' Tips

Chris Chris' Tips
Made by HEAVY METAL, these kits are the most solid, rigid kit you can find. They have been on the market since 2006. They have had very few revisions in all that time.

The mini mill will need modifications to fit the top plate For Z Axis. You will need to drill 4 holes. All mods are explained in the instructions file.

See the Documents tab for the electronics that Heavy Metal recommends.

Here are the Installation Instructions


  • 3 ball screws. 16mm x 5mm pitch
  • 3  Ball nuts preloaded for minimal  backlash
  • X axis motor mount for Nema 23 motor
  • X axis ball nut block and bearing block
  • Y motor mount for Nema 23 motor
  • Y axis ball nut block
  • Z motor mount for Nema 23 motor
  • Z axis ball nut block & bearing block
  • Zero backlash helical couplings for X, Y, Z axis for 0.25” Dia. Motor shafts
  • Thrust bearing for all 3 axis
  • Stainless steel cap screws for mounting motors, and other hardware as needed



This product works with the following mills. (If your machine is not on this list, check with us before ordering.)

  •   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
  •   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
  •   BusyBee CX612 Craftex Mini Mill
  •   SIEG SX2 Mini Mill
  •   Micro-Mark 84630 MicroLux Mini Mill


This item ships directly from our supplier in Texas to you. It might be a day or two longer before it ships, and you will receive it in a separate package from other items on your order. You might receive this item a few days before or a few days after you receive items shipped from our warehouse.


Recomended Electronics


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3 - Nema 23 drivers, KL-5056 20-50VDC 5.6A
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