Miller M-10 - User Manual

Questions and Answers

R
Rachel RichardsonJul 29, 2025
What to do if the wire does not feed in Miller Welding Accessories?
- B
  Benjamin MooreJul 29, 2025
  If the wire isn't feeding, isn't energized, or feeds unevenly, start by checking the contact tip and inspecting the gun cable for any kinks. Also, check the gun trigger plug connection at the welding power source or wire feeder. Additionally, you can blow out the liner and gun casing. If necessary, replace the gun trigger switch.
N
nicoleodonnellAug 8, 2025
What to do if wire feeding stops during welding with Miller Welding Accessories?
- K
  Kenneth BallAug 8, 2025
  If the wire feeding stops or doesn't feed properly during welding, try straightening the gun cable and replacing any damaged parts. You may also need to clean or replace the liner if it's dirty or plugged. Also, you can replace the drive roll or pressure bearing if they are worn or slipping.
S
Steven ContrerasAug 18, 2025
Why is there weld porosity in my Miller M-10 Welding Accessories?
- K
  kevin37Aug 18, 2025
  Weld porosity can occur due to several factors. You can try removing any weld spatter buildup in the nozzle. Also, ensure the inner head tube is securely tightened in the cable connector. Finally, verify the shielding gas flow and supply are adequate.

Summary

GMAW Gun Safety Precautions

Symbol Usage

Explains the meaning of warning symbols used in the manual for hazard identification.

GMAW Gun Hazards

Details specific dangers such as electric shock, hot surfaces, flying debris, and overuse.

Installing and Using the Gun Switch

Removing, Changing, and Cleaning Gun Components

Replacing Gun Switch and Head Tube

Routine Maintenance Procedures

Troubleshooting GMAW Gun Issues

This document is an owner's manual for Miller Electric Mfg. Co.'s M-10, M-15, M-25, and M-25M GMAW (Gas Metal Arc Welding) and FCAW (Flux Cored Arc Welding) guns, published in June 1999. It provides specifications, safety precautions, installation instructions, usage features, maintenance guidelines, and a parts list for these air-cooled welding guns.

Function Description

The M-10, M-15, M-25, and M-25M guns are air-cooled welding guns designed for GMAW and FCAW processes. They are used to feed welding wire and deliver shielding gas (if applicable) to the weld puddle. The M-25M model is specifically noted as a replacement gun for the MM250MP welding power source. The manual emphasizes that using gasless flux cored wire reduces the gun's duty cycle.

Important Technical Specifications

M-10 Gun:

Wire Feeds: .023 to .045 inches (0.6 to 1.1 mm) hard or flux cored wires.
Duty Cycle Rating:
- 100% duty cycle: 100 A with CO2 shielding gas.
- 60% duty cycle: 100 A with mixed gases.

M-15 Gun:

Wire Feeds: .023 to .045 inches (0.6 to 1.1 mm) hard or flux cored wires.
Duty Cycle Rating:
- 100% duty cycle: 150 A with CO2 shielding gas; 120 A with mixed gases.
- 60% duty cycle: 200 A with CO2 shielding gas; 150 A with mixed gases.

M-25 and M-25M Guns:

Wire Feeds: .023 to .045 inches (0.6 to 1.1 mm) hard or flux cored wires.
Duty Cycle Rating:
- 100% duty cycle: 200 A with CO2 shielding gas; 150 A with mixed gases.
- 60% duty cycle: 300 A with CO2 shielding gas; 200 A with mixed gases.

Gun Identification:

M-10: No diamonds on the cable jacket.
M-15: One diamond on the cable jacket.
M-25/M-25M: Two diamonds on the cable jacket.

Usage Features

Installation:

Gun Securing: The gun end is inserted into the drive assembly until it bottoms, then secured by tightening a knob.
Trigger Plug: The gun trigger plug is inserted into its receptacle, and the threaded collar is tightened. For some applications, the trigger plug may need to be cut off and 0.250 female friction terminals installed.
Wire Threading: Refer to the wire feeder manual for specific threading procedures.

Gun Switch Operation:

Trigger Switch (All Models): Pressing the switch feeds energized wire and initiates gas flow.
Dual Schedule Mode (M-25M Models Only): This mode allows selection of any combination of 9 available memories for welding schedules. Display data for this mode is found on the welding power source.
Switch A or B and Increase/Decrease Function (M-25M Models Only): These switches select program A or B and adjust the wire feed speed.

Safety Precautions (GMAW Gun Hazards): The manual highlights several hazards with corresponding safety measures:

Electric Shock: Always wear dry insulating gloves, insulate yourself from work and ground, avoid touching live electrical parts, repair damaged insulation, turn off the power source before changing parts, and keep covers securely in place.
Hot Surfaces: Allow the gun to cool before touching, avoid hot metal, and protect others from contact with hot metal.
Flying Pieces of Metal or Dirt: Wear safety glasses with side shields or a face shield.
Welding Wire Puncture Wounds: Keep hands and body away from the gun tip when the trigger is pressed.
Overuse: Follow the rated duty cycle, allow cooling periods, and reduce current or duty cycle if necessary to prevent damage and voiding the warranty.
General Safety: Read all instructions, ensure only trained personnel install/operate/service the unit, contact the distributor for clarification, and refer to wire feeder and welding power source manuals for comprehensive welding safety and EMF information.

Maintenance Features

Routine Maintenance:

Each Spool of Wire:
- Blow out the gun casing.
- Clean the nozzle and check the contact tip.
Every 3 Months:
- Replace cracked parts.
- Check the control cord.
- Inspect the gas hose.
- Examine the gun cable.
- Always turn off the welding power source and disconnect the gun before performing maintenance.

Removing Nozzle, Contact Tip, and Adapter:

Turn off the welding power source/wire feeder.
Remove the nozzle, contact tip, and adapter. The wire size is stamped on the tip and should match the wire being used.

Changing Liner:

Cut off the wire and disconnect the gun from the feeder.
Lay the gun cable out straight.
Unscrew and remove the old liner.
Blow out the gun casing.
Install the new liner, ensuring the correct stickout (3/4 inch or 20 mm; 3/8 inch for M-25 and M-25M).
Reassemble the gun in reverse order.
Thread the wire according to the welding power source/wire feeder manual.

Replacing Switch and/or Head Tube:

Turn off the welding power source/wire feeder and disconnect the gun.
Remove the handle locking nut and slide off the handle.
Remove the switch housing, install the new switch (polarity is not important), and reconnect leads. Reassemble in reverse order.
If replacing the head tube, secure the head tube in a vice.
Loosen the jam nut, remove it from the vice, and turn the head tube out by hand.
For M-25 and M-25M models, install the existing shock washer onto the new head tube and hand-tighten the head tube into the cable connector.
Place the head tube in a vice and tighten until the nuts are secure.
Remove from the vice, reposition the handle, install the switch housing, and secure with the handle locking nut.

Troubleshooting: The manual provides a table of common problems and their remedies:

Wire does not feed; wire is not energized; wire feeds unevenly: Check contact tip, kinks in gun cable, gun trigger plug connection, trigger switch, blow out liner and gun casing.
Weld porosity: Remove spatter from the nozzle, ensure the inner head tube is tight, and check shielding gas flow/supply.
Wire feeding stops or does not feed properly: Straighten gun cable, replace damaged parts, adjust drive roll pressure, change drive roll groove, readjust hub tension, clean or replace liner, and replace worn drive roll or pressure bearing.