JET JTM-4VS Mill with 3-Axis ACU-RITE 203 DRO (Quill), X & Y-Axis Powerfeeds, and Power Draw Bar is a professional-grade vertical knee mill from JET, engineered for precision metalworking, toolroom operations, and production milling. Built on a Certified Meehanite casting process foundation, this variable speed milling machine delivers consistent, reliable performance with a comprehensive digital readout system, dual-axis powerfeeds, and a pneumatic power draw bar - making it one of the most fully equipped mills in the JTM-4VS series lineup.

Key Features

• Constructed using the Certified Meehanite casting process for superior rigidity and vibration dampening during heavy cuts
• Adjustable gibs throughout allow precise tuning of fit and feel across all axes for long-term accuracy
• Heavy duty splined motor drive delivers smooth, reliable power transmission across the full variable speed range
• Internal coolant tank built into casting base for use with a coolant system (coolant pump not included)
• Large diameter quill is chromed for improved wear resistance and a smooth, consistent feel during quill operations
• One shot lubrication system simplifies routine maintenance and helps protect precision ways and bearings
• Precision hardened and ground ways and table ensure accurate, repeatable positioning across all three axes
• Spindle head is internally cooled to maintain optimal operating temperatures during extended machining sessions
• Precision bored and honed milling head ensures quality cuts and minimal runout
• Three-stage power downfeed with automatic stop for controlled, repeatable quill depth operations
• ACU-RITE 203 3-Axis DRO (Quill) provides real-time digital position readout for precise, efficient setup and machining
• X and Y-Axis powerfeeds reduce operator fatigue and improve feed consistency during longitudinal and cross-travel operations
• Pneumatic power draw bar speeds up tool changes and reduces wear on the R-8 spindle taper
• Variable spindle speed range of 60 - 4,200 RPM accommodates a wide variety of materials and tooling
• Tolerance test sheet included confirming factory-verified accuracy at time of manufacture
• Backed by the industry-leading two-year full service and parts warranty

Specifications

• Stock Number: 690139
• MPN: JT9-690139
• Brand: JET
• Style (Type): Variable Speed R8
• Number of Axis: 3 (Quill)
• Motor: 3 HP, 230/460V, 3Ph
• Range of Spindle Speeds (RPM): 60 - 4,200
• Spindle Taper: R-8
• Spindle Travel (In.): 5
• Quill Diameter (In.): 3-3/8
• Quill Down Feed Rates (IPR): .0015 - .003 - .006
• Collet Capacity: 1/8 - 7/8
• Table Longitudinal Travel (In.): 34
• Table Longitudinal Travel With Powerfeed (In.): 28-3/4
• Table Cross Travel (In.): 12
• T-Slot Centers (In.): 2-1/2
• Distance Spindle to Column, Max. (In.): 19
• Max Distance Spindle to Table (In.): 17-1/2
• Powerfeed: X and Y-Axis
• Power Draw Bar: Pneumatic
• Overall Dimensions (L x W x H) (In.): 66 x 63 x 85
• Country of Origin: Taiwan
• Prop 65: Cancer and Reproductive Harm

What's Included

• JET JTM-4VS Variable Speed Knee Mill
• ACU-RITE 203 3-Axis DRO (Quill)
• X and Y-Axis powerfeeds
• Pneumatic power draw bar
• Tolerance test sheet

Frequently Asked Questions

What is the spindle speed range on the JET JTM-4VS, and is it truly variable?

Yes - the JTM-4VS features a continuously variable spindle speed range of 60 to 4,200 RPM, allowing the operator to dial in the ideal cutting speed for a wide variety of materials and tool diameters without stopping to change belt positions.

Does the mill come with a coolant pump included?

The JTM-4VS includes an internal coolant tank built directly into the casting base for use with a coolant system; however, the coolant pump itself is not included and must be purchased separately.

What does the ACU-RITE 203 DRO add to this mill, and how many axes does it cover?

The ACU-RITE 203 is a 3-axis digital readout system configured for the quill (Z-axis) as well as the X and Y axes. It provides real-time positional data directly on the display, significantly reducing the need for manual calculations and improving setup speed and repeatability during machining operations.

What spindle taper does the JTM-4VS use, and what is the collet capacity range?

The JTM-4VS uses an R-8 spindle taper, which is the industry-standard taper for Bridgeport-style knee mills. It accepts collets in the range of 1/8 to 7/8 inch, providing broad compatibility with end mills, drill chucks, boring heads, and other common R-8 tooling.