Assembly / What's Included

Each MG-2 guard includes a CNC billet aluminum mounting plate and articulating arm assembly, powder coated in OSHA Safety Orange; a curved 1/4 inch polycarbonate (Lexan) shield, RMS-1, 15 inches wide by 9 inches tall with 135 degree bend geometry; the longer replacement mounting bolts needed to install around the quill feed selector, so no machine drilling is required; and installation instructions. Interlocked models (MG-2-SK1 or MG-2-SK2) add a pre installed safety interlock switch, but still require a separately purchased motor control device to interface the switch's 2A output with your machine's 3 phase power.

Configuration Options

• MG-2: 2.5 inch (up to 2.75 inch / 70mm) square bolt pattern; fits Bridgeport and most import copies
• MG-2T: 3.0 x 3.5 inch rectangular bolt pattern; fits TRAK DPM5, Clausing bed mills, and similar machines
• Add SK1 for a 120VAC/24VDC magnetically actuated safety interlock switch
• Add SK2 for a 24VDC RFID style safety interlock switch (requires a stable 24VDC supply)
• Special mounting plates available on request for Series II Bridgeports with power downfeed and other non standard knee mills

Shield Options

• Standard: curved RMS-1 shield, 15 x 9 inches, 1/4 inch thick polycarbonate
• Tall: 12 inch tall RMS-1 replacement, for taller workpieces
• Flat: optional RMS-2 shield, 16 x 10 inches, for use with rotary indexers or tilted heads
• Custom shield sizes are available; contact ATS or PowerSafe for non standard geometries

Materials & Construction

• CNC billet aluminum mounting plate and arm assembly, powder coated OSHA Safety Orange
• 1/4 inch thick polycarbonate (Lexan) shield
• Heavy duty steel adjustable handles, splined so they can be repositioned while tight

Applicable Safety Standards

Standards to be confirmed by PowerSafe. See: ATS Safety product documentation for the MG-2 Head Mount Milling Machine Guard, section to be confirmed.

Installation Instructions

Guard Does Not Stay in Position / Drifts During Operation

Articulating arm moves unexpectedly; shield repositions under vibration or tool loads

• Never adjust the guard while the spindle is running; always reposition with the machine stopped
• Check all arm joint hardware (knobs, bolts, pivot points) for tightness; re-torque as needed
• Verify adjustable handles have been fully tightened after positioning; handles pull out and rotate 360 degrees, and if not locked down they allow unintended movement
• Inspect arm joints for wear; heavy continuous vibration environments may require more frequent tightening checks
• Confirm the shield isn't contacting the workpiece or fixture during the cut, which can deflect the arm

Guard Cannot Be Positioned to Cover the Workpiece

Shield does not reach, or curved shield hits the fixture, vise, or rotary indexer

• Check whether the curved RMS-1 shield can be substituted with the flat RMS-2 shield, which has a lower profile geometry better suited for rotary indexers and angled setups
• Verify the articulating arm is fully extended and that all joints are loose enough to allow repositioning before re-tightening
• For unusually tall workpieces, check whether the 12 inch tall RMS-1 replacement shield provides adequate coverage (standard shield is 9 inches tall)
• Adjust so the shield's bottom edge sits just above the vise, allowing the guard to swing open without hitting the vise or another obstruction
• For custom workpiece geometries, contact PowerSafe; custom shield sizes are available from ATS

Mounting Plate Does Not Fit the Machine

Bolts don't align; plate is the wrong size; cannot install without drilling

• Confirm which bolt pattern the machine uses before ordering: measure center to center distance on the quill feed selector mounting bolts
  • 2.5 inch (up to 2.75 inch / 70mm) square pattern leads to MG-2
  • 3.0 x 3.5 inch rectangular pattern leads to MG-2T (TRAK DPM5, Clausing bed mill, and similar)
• The MG-2 mounting plate is slotted and accommodates up to 2.75 inch square, not just exactly 2.5 inch
• For Series II Bridgeports with power downfeed or other non standard knee mills, contact ATS or PowerSafe for a special mounting plate; standard plates may not fit
• Do not drill the machine to force fit a mismatched plate; this defeats the bolt on design and may create machine damage or safety issues

Guard Arm Swings Incorrectly / Won't Open the Full 180 Degrees

Front arm binds, catches, or cannot reach full open position

• Verify there is adequate clearance to the left of the machine head for the arm to swing fully open; equipment or tooling stored near the machine may obstruct travel
• Inspect the arm pivot for debris, bent components, or damage from a previous impact
• Check that joint hardware isn't overtightened to the point of preventing free rotation when knobs are loosened

Safety Interlock Switch Does Not Signal Correctly (Interlocked Models)

Machine does not stop when guard opens; motor control does not respond to switch state

• Confirm the safety switch output (rated 2A max) is wired to a compatible motor control or safety relay; the switch alone cannot directly interrupt a 3 phase machine motor
• Verify wiring connections are secure at the switch, motor control, and any terminal strips; check for loose or damaged terminals
• For SK1 (magnetic) models: confirm the actuator magnet on the arm is correctly aligned with the switch body when the guard is closed; misalignment prevents a correct closed signal
• For SK2 (RFID) models: confirm 24VDC supply is present and stable; the RFID switch requires DC power and will not operate on AC
• Test the switch in isolation by manually cycling it (open/close) and verifying the output state changes at the motor control or relay input
• If the switch is suspected damaged, contact PowerSafe for a replacement; the interlock retrofit kit can replace a switch on an existing guard

Machine Head Tilt Compatibility Issue

Guard arm contacts the machine head during operation; guard is unstable when head is tilted

• The MG-2 is designed for front to back head tilt only
• If the machine's head tilts left to right, the MG-2 arm will conflict with the head geometry; the MG-3 Ram Mount guard is the correct product for left to right tilt applications
• Do not modify the arm assembly to accommodate a tilt geometry it isn't designed for

Preventive Maintenance

To keep the MG-2 performing reliably:

• Inspect all arm joint hardware for tightness at regular intervals, at minimum monthly in high vibration environments
• Clean polycarbonate shield surfaces with a mild soap and water solution; avoid solvent based cleaners (acetone, MEK, lacquer thinner), which will craze and weaken the Lexan
• Inspect the shield for cracks, chips, or stress marks after any heavy chip impact event; replace immediately if damage is found
• For interlocked models, cycle the guard open and closed at each maintenance interval and verify the motor control responds correctly to the switch state
• Check the mounting plate bolts for looseness; vibration from the machine can back out fasteners over time

Fault Tracking & Continuous Improvement

• Log any guard adjustment, shield replacement, or interlock fault, including the machine and date
• Look for recurring patterns, such as repeated loosening tied to a specific machine's vibration levels
• Use this history to plan hardware re-torque schedules and shield replacement before damage affects protection