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Charter Oak Automation

CNC Controlled Machinery for Industrial and Serious Hobbyists

Charter Oak Automation
340 Quinnipiac Street
Building 19
Wallingford, CT 06492
(203) 562-0699

Home » Charter Oak Automation Products » Manual Square-Column Bed Mills

Manual Square-Column Bed Mills

Large 12Z Bed Mill

Benchtop Bed Mill


Terms of Sale: Large 12Z Mill Benchtop Mill
Base Price: $2,350.00 $1,699.00
Warranty: One year One year
Working Envelope (Travel):
Total Travel (Volumetric): 6,864 in3 1,844 in3
X-Axis Travel (Longitudinal): 26" 17″
Y-Axis Travel (Cross-Table): 12" 7″
Z-Axis Travel (Quill Retracted): 22" 15½”
Quill Travel 4¾" 4¾”
Table Details:
Table Work Surface (Linear): 39½" × 9⅜" 31½” × 9½”
Table Work Surface (Areal): 370.3125 in2 299.25 in2
T-Slots: 3 Slots, ⅝” Each 3 Slots, ⅝” Each
Standard Spindle Speeds (RPM):
Standard Gears (2 HP) 100, 190, 330, 480, 910, 1600 95, 175, 310, 450, 850, 1500
Upgraded Spindle Speeds (RPM):
Dual-Speed Belt Drive 945, 2345 945, 2345
3 HP VFD 60 to 3600 60 to 3375
3 HP VFD with Dual-Speed Belt Drive 100 to 5400 100 to 5400
Spindle and Quill Details:
Spindle Taper: R8 (NT30 optional) R8 (NT30 optional)
Spindle Center to Column: 12½" 10¾”
Spindle to Table (Min, Quill Retracted): 3" 1½”
Spindle to Table (Max, Quill Retracted): 22" 17″
Spindle Nose Diameter: 3.79″ 3.79″
Miscellaneous Details:
Head Rotation: ±90° ±90°
Power Requirements: 220-240V AC, 50/60Hz single phase 220-240V AC, 50/60Hz single phase
Measurements/Dials: Inches Inches
Column Type: Square Square
Ways: Ground dovetails Ground dovetails
Weight: 770 lbs. 650 lbs.
Required Floor Space for Max Travel (with 28″ Stand): 90″ H × 87″ W × 38″ D 82″ H × 72″ W × 32″ D

Optional Upgrades:

For increased spindle horsepower and maximum speed, with infinitely variable speed control.
Two-Speed Belt Drive
For higher maximum spindle speeds, especially when combined with the 3 HP VFD to provide fine-grained speed control.
Mach-1 Quick Change Tooling System (Start-Up)
Change tools in seconds with just a push on the quill lever. (Not compatible with the NT30 taper spindle or belt drive upgrades.)
Mach-1 Quick Change Tooling System (Complete)
An expanded version of the start-up package, with more collets and an organizer. (Not compatible with the NT30 taper spindle or belt drive upgrades.)
Heavy Duty Stand
A skeletal (open-work) welded steel tube stand with leveling feet. Custom heights built-to-order for no extra charge.
Heavy Duty Stand with Wheels
Our popular heavy-duty stand with leveling feet and added 360° locking casters for easy repositioning.
Chip Tray
A welded steel chip tray, powder coated for corrosion resistance.
10-Gallon Flood Coolant System
Prolongs cutting tool life and helps to clear chips from the tool path.
Easson ES-8A 3-Axis DRO (5 µm Res.)
A quality entry-level Digital Read-Out system, using glass scales with metal protective covers.
Fagor 30i 3-Axis DRO (0.1 µm Res.)
A high-precision Digital Read-Out system, using glass scales with metal protective covers. Includes programming assistance for common operations.
Fagor 40i 3-Axis DRO (0.1 µm Res.)
The same quality and features of the Fagor 30i, but with a full-color screen for on-screen 3D diagrams and motion simulation.
One-Shot Oiling System
Lubricate the ways and lead screws with a single lever.
X-Axis Power Feed
Fast, smooth motion at the press of a lever.
NT30 Taper Spindle
For NT30-taper tooling, offering superior side-loading force characteristics for heavier operations.

A Mill That Keeps Pace With Your Growing Needs

Purchasing a new mill is an investment in the future. For business owners, an efficiently used mill will increase productivity and profit. For hobbyists, it provides finer control over your craft. And for educators, it is an investment in the next generation of machinists. But no matter what use our mills are put towards, your machining needs tend to grow over time. That’s why we provide a diverse range of upgrades that lets your investment keep pace with your changing needs.

Mach-1 Quick Change Tooling System

The most popular quick change tooling system has been adapted by Mach-1 Systems Inc. specially for our mills. Swapping a tool takes only seconds, with just a small push on the quill lever—no wrenches or awkward reaching needed!

The patented Mach-1 system replaces the standard draw bar in our mills, gripping your tools with 600 lbs. of holding force. Tool length offsets are retained between collet changes, increasing your time efficiency and reducing human error. For industrial customers, the payback period from time savings alone can be as short as a few months at typical shop rates.

NT30 Spindle

Tooling for our standard R8 spindle has the advantages of being inexpensive and easily obtained, but some jobs require more spindle rigidity and resistance to side-loading forces. When you need bigger tooling or larger cutting passes to improve your machining efficiency, our NT30 spindle upgrade lets you get the job done faster.

3 Horsepower Sensorless Vector Variable Frequency Drive

When you need more power and speed at the spindle, our 3 HP sensorless vector VFD spindle motor provides it. The VFD increases our mill’s maximum spindle speed to 3,600 RPM. When used with our optional dual-speed belt drive, maximum speed is further increased to 5,400 RPM.

But high speed isn’t everything, and ultimately your optimum cutting speed will vary by material, pass depth, and cutting tool. Furthermore, no spindle motor’s output torque remains constant at all speeds, so horsepower suffers at low and high RPM without a matching mechanical advantage. The VFD lets you select any spindle speed you want, but in conjunction with our six-speed gearbox you can stay closer to the top of the torque curve than with competing mills that offer fewer gear or pulley ratios.

Our VFD uses sensorless vector technology, which yields improved torque and more speed consistency as you approach zero RPM compared to other VFDs and helps to improve your machining results for slow operations like tapping. The cooling fan is electrically powered rather than manually coupled to the shaft, so it maintains a constant flow of air even at low RPM to prolong the life of the motor.

Digital Read-Out Systems

Save time and reduce human error by integrating a DRO into your mill to quickly and accurately position your workpieces. Digital Read-Outs ordered at the time of purchase are pre-installed before your mill leaves our Connecticut workshop. If ordered later, our technicians can walk you through their installation.

DRO Model Axes Mounting Resolution Scale Price (Installed)
Easson ES-8A 3-Axis X, Y, Quill 5 µm Glass $799.00
Fagor Innova 30i 3-Axis X, Y, Quill 0.1 µm Glass $2,173.90
Fagor Innova 40i 3-Axis X, Y, Quill 0.1 µm Glass $2,425.90
Features Common to All Models
  • Metric/Imperial Unit Conversion
  • Circular Bolt-Hole Patterns (PCD)
  • Linear Tool Positioning
  • Grid Tool Positioning
  • Tool Positioning on Inclines
Easson ES-8A Digital Read-outEasson ES-8A 3-Axis Digital Read-Out System

Offering solid precision at an affordable price, Easson’s ES-8A DRO is perfect for cost-conscious hobbyists and home machinists. Glass scales with durable metal covers, armored metal cables, and quality construction render this model more robust and accurate than cheap imported DROs based on capacitive scales. A collet holder comes standard on the display’s mounting arm.

Fagor 30i DRO SystemFagor 30i 3-Axis Digital Read-Out System

The Fagor 30i DRO offers our highest-resolution glass scales, and is suitable for machining operations requiring extreme precision. Integrated programming assistance is available for common operations, telling you exactly where to position your tool next.

Fagor 40i DRO SystemFagor 40i 3-Axis Digital Read-Out System

The Fagor 40i DRO system offers similar advantages to the 30i model, but additionally provides a more intuitive interface through a full-color TFT screen. The programming assistance offered in the 30i model is graphically displayed in on-screen diagrams, and the results of the programmed operations can be displayed in 3D using machine simulation.
Fagor 40i Technical Information (PDF)