This document describes a range of Walter angle grinders, including models like MINI 4.5", MINI PS 4.5", MINI PLUS 5", SUPER 5", SUPER 5" PS, PRO 5", BIG 6", BIG 6" PS, and QUICK-STEP FINISHER. These tools are designed for various surface technologies applications.

Function Description

Walter angle grinders are versatile power tools primarily intended for grinding, sanding, abrasive cutting-off operations, and wire brushing. They are suitable for working with metal, concrete, stone, and similar materials without the use of water. The QUICK-STEP FINISHER 6" model has an extended capability for polishing work. For demanding continuous polishing, the QUICK-STEP BIG-BUFF III polisher is recommended. Models designated with "DYNAMAX™" are particularly well-suited for tasks involving wire brushes, flap discs, and sanding discs due to their speed selection thumbwheel.

The tool's operation involves a rotating accessory that performs the desired surface treatment. For grinding and sanding, the machine is pressed evenly onto the surface and moved back and forth to prevent overheating. Rough grinding typically requires an application angle of 30°-40°. For abrasive cutting-off, the tool should always be worked against the run of the disc to prevent kickback and should be guided evenly at a speed appropriate for the material. Wire brushing also involves pressing the machine evenly onto the surface.

The angle grinders feature a spindle locking button (4) for easy accessory changes. Depending on the model, accessories can be secured using a "Quick-R" clamping nut (1) or a 2-hole nut (13) with a 2-hole spanner (14). The "Quick-R" system is identified by a red spindle lock button with a "Quick-R" logo. The 2-hole nut offers different orientations for thin and thick grinding discs.

Speed adjustment is available on models with a thumbwheel (8), allowing users to select between low and high speeds. High speeds are recommended for cutting, roughing, cup wheel, and diamond cutting discs, while medium speed is for brushes, and low to medium speed for sanding plates.

The tools are equipped with a safety guard (12) that must always be used for the respective wheel. The guard is attached by pressing a lever (15), positioning the guard, and then releasing the lever and turning the guard until it engages securely.

Important Technical Specifications

The specifications for the Walter angle grinders vary by model, as detailed in the table on page 4 of the manual. Key technical specifications include:

Ø (max. diameter of the accessory): Ranges from 4 1/2" (115 mm) to 6" (150 mm).
tmax,1 (max. permitted thickness of the clamping shank on accessory when using 2-hole nut): Not explicitly stated in mm, but the "Quick-R" clamping nut should not be used if the clamping shank is thicker than 6.8 mm.
tmax,2 (max. permitted thickness of clamping shank on accessory when using "Quick-R" clamping nut): Not explicitly stated in mm, but the "Quick-R" clamping nut should not be used if the clamping shank is thicker than 6.8 mm.
tmax,3 (roughing disc/cutting disc max. permitted thickness of accessory): Not explicitly stated.
M (spindle thread): 5/8"-11 UNC.
n (no-load speed min-1): Ranges from 7600 to 11000 min-1.
nv (no-load speed (adjustable) rpm): Available on DYNAMAX models, ranging from 2800-11000 rpm or 2000-7600 rpm.
P1 (rated input power W): Ranges from 900 W to 1700 W.
P2 (power output W): Ranges from 550 W to 1040 W.
120V (Current A): Ranges from 8.5 A to 14.5 A.
m (weight without mains cable lbs (kg)): Ranges from 4.6 lbs (2.1 kg) to 6.2 lbs (2.8 kg).
Vibration emission values (m/s²):
- ah,SG (surface grinding): 4.0/1.5 to 6.0/1.5 m/s².
- ah,DS (sanding with sanding plate): <2.5/1.5 to 4.2/1.5 m/s².
- ah,P (polishing): 3.6/1.5 m/s² or <2.5/1.5 m/s².
Kh.SG/DS/P (Uncertainty (vibration)): 1.5 m/s².

The tools are Class II Construction, indicating double insulation. They are designed for alternating current. Models with DIALSPEED or DYNAMAX electronics may experience speed fluctuations due to high-frequency interference, which should dissipate once the interference source is removed.

Usage Features

Safety First: Always read all safety warnings and instructions to reduce the risk of electric shock, fire, and serious injury. Wear personal protective equipment, including eye protection, dust masks, hearing protectors, gloves, and workshop aprons.
Work Area: Keep the work area clean, well-lit, and free of flammable materials. Keep children and bystanders away.
Electrical Safety: Ensure power tool plugs match outlets. Avoid body contact with earthed surfaces. Do not expose power tools to rain or wet conditions. Use extension cords suitable for outdoor use when operating outdoors. A residual current device (RCD) protected supply is recommended for damp locations. Always install an RCD with a maximum trip current of 30 mA upstream.
Personal Safety: Stay alert, use common sense, and avoid operating the tool when tired or under the influence of substances. Prevent unintentional starting by ensuring the switch is off before connecting to power or changing accessories. Remove adjusting keys or wrenches before turning on the tool. Maintain proper footing and balance. Dress properly, avoiding loose clothing or jewelry.
Accessory Selection: Use only accessories specifically designed and recommended by Walter. Ensure the rated speed of the accessory is at least equal to the maximum speed marked on the power tool. The outside diameter and thickness of the accessory must be within the tool's capacity rating. Threaded accessories must match the grinder spindle thread, and flange-mounted accessories must fit the locating diameter of the flange.
Accessory Inspection: Before each use, inspect accessories for damage (chips, cracks, tears, excess wear, loose wires). If the tool or accessory is dropped, inspect for damage or install an undamaged accessory. Run the power tool at maximum no-load speed for one minute after installing an accessory to test for breakage.
Kickback Prevention: Maintain a firm grip on the power tool with both hands and position your body and arm to resist kickback forces. Always use the auxiliary handle (11). Never place your hand near the rotating accessory. Avoid working in areas where kickback would propel the tool towards you. Exercise special care when working around corners or sharp edges. Do not use saw blades.
Specific Operations:
- Grinding/Sanding: Apply even pressure and move back and forth to prevent overheating.
- Abrasive Cutting-Off: Work against the disc's rotation. Guide the machine evenly without tilting or excessive force. Do not "jam" the wheel or apply excessive pressure. Support large workpieces to minimize pinching and kickback.
- Wire Brushing: Apply moderate pressure. Be aware that wire bristles can be thrown from the brush.
- Polishing (QUICK-STEP FINISHER 6"): Ensure no loose parts of the polishing bonnet or attachment strings are spinning freely.
Gear Housing Rotation: The gear housing can be rotated to a desired position by unscrewing the fastening screw (a) of the lever (15) and the four gear housing screws (b), rotating the housing, and then re-securing the screws and lever.
Switching On/Off:
- Slide Switch (5): Push forward to turn on. For continuous operation, tilt downwards until it engages. Press the rear end to turn off.
- Paddle Switch (9) with Switch-on Lock (10): Slide the switch-on lock in the direction of the arrow and press the trigger (9) to turn on. Release the trigger (9) to turn off.
Troubleshooting:
- Electronic Signal Display (7) lights up and load speed decreases: Indicates overload. Run the machine in idling until the indicator switches off.
- Electronic Signal Display (7) flashes and machine doesn't start: Restart protection is active. Switch the machine off and on again.

Maintenance Features

Cleaning: Regularly and thoroughly clean the power tool's air vents using a vacuum cleaner to prevent dust accumulation, which can impair cooling and cause electrical hazards. Disconnect from the power source and wear protective glasses and a dust mask during cleaning. Do not direct escaping particles or exhaust air towards yourself or others. Avoid sweeping or blowing dust, as this stirs it up. Vacuum or wash protective clothing.
Repairs: Repairs to electrical tools must only be carried out by qualified electricians. If the connection lead is damaged, it must be replaced with a special connection lead. Contact your local Walter representative for repairs or spare parts. Spare parts lists can be downloaded from www.walter.com.
Storage: Store idle power tools out of reach of children and untrained users.
General Maintenance: Check for misalignment or binding of moving parts, breakage of parts, and any other condition that may affect operation. Have damaged tools repaired before use. Keep cutting tools sharp and clean.
Environmental Protection: Dispose of generated grinding dust appropriately, observing national regulations for environmentally compatible disposal and recycling of machines, packaging, and accessories.

Walter MINI 4.5 - Page 38

Table of Contents