X2 Mill
This page documents the setup and modification of the Harbor Freight Mini Mill (Sieg X2 Clone).
General Information
The Harbor Freight Mini Mill (SKU 44991) is a clone of the Sieg X2 Mini Mill. It is one of various clones of the Sieg X2 on the market, including others by Grizzly, Little Machine Shop, Micro Mark, etc. The Harbor Freight variant has a variable speed 350W DC motor with 2 gear ranges for 0-1100 or 0-2500 RPM, and an R8 taper spindle. The mill has a tilting column with -45 to +45 degree range, and has a tension spring supported mill head. The main table is 3-5/8″ x 15-3/4″, and has a total X travel of 9″, Y travel of 4", and Z travel of 8-1/2". The X and Y dials have 62.5 mils per turn with 1 mil graduations. The Z dial has 60 mils per turn with 1 mil graduations.
3D Model
A 3D CAD model of the Sieg X2 along with CNC additions is available at GrabCAD here: https://grabcad.com/library/sx2-mini-mill-cnc
Setup/Modifications
11/12/2015 - Harbor Freight Mini Mill arrives; damaged in shipment, both hold-down bolts came loose and the unit was dropped on the Y axis jamming the notch into the bearing/sleeve thus preventing any movement of the Y axis. Contacted customer service who made a note to return the mill to a local store and get a receipt to place a replacement order.
11/13/2015 - Damaged mill returned to Harbor Freight.
11/16/2015 - Replacement mill ordered by phone, shipping charge was waived since it was not refunded by the store with the damaged unit return.
11/20/2015 - Replacement mill arrives, was only held down with one bolt (which was loose), but undamaged. Stripped down unit, cleaned, and lubricated Y and X axes and adjusted gibs.
11/22/2015 - Stripped and cleaned Z axis/mill head, lubricated and adjusted gibs, and partially mounted unit to bench. Removed power supply box from back as it interfered with the shelf on the bench.
11/30/2015 - Fully mounted unit to bench, re-adjusted gibs.
12/4/2015 - Mounted and squared vise, adjusted motor gear meshing, re-attached baffles, removed drill chuck and attached 3/8" R8 collet. Made first cuts in aluminum (shown below).
12/7/2015 - Milled holes in 2 aluminum pieces to be used as spacers for mounting the Z-axis DRO. Drilled and tapped 2 M6 holes in mill column, mounted Z-axis DRO fixed portion. Mounted vise properly using step blocks.
12/14/2015 - Purchased a bandsaw to help with rough-cutting parts. Finalized Z-axis DRO bracket design and cut + milled the two brackets, as well as a small spacer to go between them. Waiting on a 3.3mm drill bit to use with the M4 tap to drill/tap/install the brackets to the mill. Still need to drill and counterbore the holes for the DRO body and mill side mounts.
X2 Mill System Cost
Part | Quantity | Unit Cost | Total Cost | Source |
Harbor Freight Mill #44991 | 1 | $587.45 | $587.45 | Harbor Freight Tools |
12" Digital Readout | 2 | $31.54 | $63.08 | eBay |
6" Digital Readout | 1 | $28.29 | $28.29 | eBay |
3" Screwless Vise | 1 | $59.95 | $59.95 | Little Machine Shop |
Edge Finder | 1 | $7.50 | $7.50 | Little Machine Shop |
3/8" R8 Collet | 1 | $6.95 | $6.95 | Little Machine Shop |
Shipping/Handling/Tax | 1 | $13.38 | $13.38 | Little Machine Shop |
58 Piece Clamping Kit 7/16" | 1 | $48.05 | $48.05 | Amazon |
Dial Test Indicator | 1 | $30.51 | $30.51 | Amazon |
1/2" R8 Collet | 1 | $7.59 | $7.59 | Enco |
2 Flute HSS End Mills: 1/4", 5/16", 7/16", 3/8", 1/2" | 1 | $53.41 | $53.41 | Enco |
HSS/Cobalt Screw Machine Drills: 5/32", 1/4", 3/8", 1/2" | 1 | $20.55 | $20.55 | eBay |
M6x1 HSS Spiral Flute Tap | 1 | $10.04 | $10.04 | Amazon |
Tap Wrench | 1 | $8.77 | $8.77 | Amazon |
M6 Washer x50 | 1 | $4.88 | $4.88 | eBay |
M6 Hex Cap Screw x20 | 1 | $9.22 | $9.22 | eBay |
Aluminum Lubricant | 1 | $13.94 | $13.94 | Amazon |
White Lithium Grease | 1 | $4.46 | $4.46 | O'Reilly Auto Parts |
Mobil One 10W-30 Synthetic Oil | 1 | $7.84 | $7.84 | O'Reilly Auto Parts |
Magnetic Base for Test Indicator | 1 | $18.43 | $18.43 | Amazon |
Wood Spacer for Mill Base (0.75" x 2.5" x 16") | 2 | $1.05 | $2.10 | Home Depot |
Hardware for Mounting Mill to Bench (Fender Washers, Washers, 3/8" Nuts) | 4 | $1.46 | $5.84 | Home Depot |
Odorless Mineral Spirits | 1 | $6.83 | $6.83 | Home Depot |
M6 Hex Nut | 8 | $0.59 | $4.71 | Home Depot |
M6x30 Socket Cap Screw | 6 | $0.65 | $3.92 | Home Depot |
Sheet Aluminum 18x6x0.025" | 1 | $9.78 | $9.78 | Home Depot |
3/4" x 3 1/2" Cariage Bolt | 4 | $0.66 | $2.66 | Home Depot |
5mm HSS Drill | 1 | $4.97 | $4.97 | eBay |
10pc 6" Thin Parallel Set | 1 | $35.83 | $35.83 | Amazon |
Machinist Square | 1 | $7.95 | $7.95 | Amazon |
Total Cost | $1085.22 | (as of 12/8/15) |
Photos
Resources
CNC
http://www.hossmachine.info/cnc_conversion.html
http://www.fignoggle.com/plans/cncplans.htm
http://www.mini-lathe.com/Mini_mill/Modifications/Power_feed/power_feed.htm
http://plsntcov.8m.com/grizzley.html
http://www.cncfusion.com/minimill1.html
https://www.ocf.berkeley.edu/~davytong/personal_projects_and_hobbies/mill2.htm
http://www.mendingthings.com/?page_id=503
DRO
http://www.yuriystoys.com/p/android-dro.html
http://www.yuriystoys.com/p/msp430-launchpad-mixed-scale-dro.html
http://www.rysium.com/projects/189-mini-mill-modifications
https://sites.google.com/site/davemarkowitzsmachineshop/projects/grizzly-g8689-mill-dro
http://www.yuriystoys.com/2014/02/dro-scale-calibration.html
http://benchtopmachineshop.blogspot.com/2013/05/mill-dro_31.html
General
http://littlemachineshop.com/info/minimill_compare.php
http://littlemachineshop.com/info/MiniMillUsersGuide.pdf
http://www.littlemachineshop.com/Projects/ViseClamps.php
http://www.cnccookbook.com/CCMillTramming.html
https://lanzerbot.wordpress.com/2014/12/17/stiffening-the-vertical-column-on-the-x2-mill/
Upgrades
http://littlemachineshop.com/products/product_view.php?ProductID=2258&category=
http://www.cnczone.com/forums/benchtop-machines/55239-x2-timing-belt-drive-cheap-course.html
http://www.cnczone.com/forums/benchtop-machines/111328-20-buck-x2-belt-drive-2.html
http://www.cnczone.com/forums/benchtop-machines/61507-20-00-x2-belt-drive.html