4246S

Overview

The Hobart 4246S Mixer-Grinder combines batch mixing and grinding in one commercial food-processing machine. Its separate drive systems operate the mixing arm and grinder worm independently: the 1 HP mixing motor turns the arm, while the 5 HP grind motor drives the worm. The standard 4246S is identified in the operator manual as a 6 HP total unit.

The hopper holds up to 140 lb (64 kg), depending on the product. During mix-only operation, the mixing arm turns while the hopper conveyor screw remains stationary. In Mix/Grind operation, the conveyor screw feeds product toward the grinding end as the machine mixes and grinds. The WEDGE cylinder draws product through its large upper opening to feed the grinding end.

Key Features

• Separate mixing and grinding drives: A 1 HP motor operates the mixing arm, and a 5 HP motor operates the grinder worm.
• #32 grinding end: The unit accepts #32-size knife and plate assemblies. These are not included with the machine.
• WEDGE cylinder: Hobart's cylinder design pulls product through the upper opening toward the grinding end.
• Two operating modes: Select mix-only operation or Mix/Grind operation using the front controls.
• Convertible hopper lid: The model's lid can be arranged for left- or right-side hopper loading.
• Safety interlock: The hopper lid must be in its operating position for the grinder motors to start. The operator manual states that opening the lid shuts power to the motors.
• Optional foot control: A pneumatic foot switch can be ordered and can be added later. In foot-switch ON mode, it operates Mix/Grind; the Mix Start and Grind Start buttons are inoperable.

Specifications

• Manufacturer: Hobart.
• Model: 4246S, standard model.
• Equipment type: Mixer-grinder.
• Grind motor: 5 HP.
• Mix motor: 1 HP.
• Total motor rating: 6 HP, as stated for the 4246S on its operator manual data-plate description.
• Hopper capacity: Up to 140 lb (64 kg), depending on the product.
• Grinding head: Size #32; knife and plate assemblies are not included.
• Mixing-arm speed: 23 rpm.
• Grinder-worm speed: 216 rpm.
• Fresh boneless beef grinding rate: 55 to 60 lb (25 to 27 kg) per minute, first or second cutting through a 1/8 in. plate.
• Fresh boneless pork grinding rate: 60 to 65 lb (27 to 29 kg) per minute, second cutting through a 3/16 in. plate.
• Electrical details reported for a 4246S listing: 208 V, 3 phase, 60 Hz, 30 A. The operator manual instructs users to verify the electrical supply against the machine data plate.
• Hopper material and finish: Glass-bead-finished stainless steel, as listed in Hobart's 4246 product specification sheet.
• Other construction details listed for the 4246: Stainless steel panels enclose the base and motors; the mixing arm and conveyor screw are tinned; the end ring and cylinder are stainless steel.

Installation & Requirements

Before installation, check the data plate under the hopper on the right side of the machine and confirm that the available electrical supply matches it. The manual specifies a cord and plug and calls for connection to an appropriately sized, grounding-type receptacle. The 4246S equipment listing reports 208 V, 3 phase, 60 Hz and 30 A; confirm the actual unit's data plate rather than relying solely on a listing. Electrical and grounding connections must comply with applicable electrical codes.

After unpacking, inspect the machine for shipping damage. The manual says to retain the packaging and contact the carrier within 15 days of delivery if damage is found. The legs ship separately and are installed using a 15/16 in. socket, with the leg fasteners torqued to 50 ft-lb. The lower side panels are packed on top of the unit. Remove the spanner wrench and meat deflector from inside the hopper. The conveyor screw, mixing arm and cylinder are assembled at the factory; remove the shipping plate and rubber spacer from the chopping end and install the required #32 knife and plate assembly.

Level the machine front-to-back and side-to-side by loosening the two set screws on the caster or leg shaft. Tighten both set screws after levelling. The manual states that the machine is shipped with transmission oil installed. If oil loss is observed, check both transmission oil levels before operation and contact a Hobart Service Office.

If fitting the optional pneumatic foot switch, remove the lower front panel screws and open the knockout hole beneath the frame rail, approximately 4 in. from the left side. Route the hose through the opening and around the left corner of the control box without kinking it. Connect the hose to the metal nipple on the left side of the control box, secure it with the saved clamp close to the hose end, and reinstall the panel. The manual warns that a loose hose or clamp can cause the foot control to malfunction.

Operation

The front controls provide Mix Start, Mix/Grind Start, Stop and Foot Switch On/Off functions. Mix Start runs the mixing arm. Mix/Grind Start runs both the mixing arm and conveyor screw. Stop halts operation. With the foot switch set to ON, the foot switch operates Mix/Grind mode and the Mix Start and Grind Start buttons are inoperable. In this mode, the manual notes that holding the Stop button stops the machine only for as long as the button is held.

Before using the grinding cylinder, take it apart and wash it thoroughly. The WEDGE cylinder is marked TOP and BOTTOM; install it with TOP visible. Hand-tighten the end ring. Do not overtighten it. Apply tallow or mineral oil to the knife and plate cutting surfaces before use. The manual says not to use a plate with hole size smaller than 3/32 in.; it also states that knives and plates need to be sharp and true for proper cutting.

For a first grind, fill the hopper, close and latch the lid, then press Mix/Grind Start. Do not overfill: the manual warns that doing so can bend the lid and may open the interlock circuit. Press Stop to stop grinding. For a second grind, fill the hopper and close and latch the lid, then press Mix Start to mix for the desired time. Press Stop, then press Mix/Grind Start to grind, or use the optional foot switch. The hopper's stated normal total capacity is up to 140 lb, depending on the meat or product.

To check motor rotation during installation, place the grinder cylinder in position and close the hopper lid. Press Mix/Grind Start and, viewed from the front, verify that the mixing arm and worm turn counterclockwise. If they do not, disconnect electrical power and interchange any two supply leads at the receptacle. Reconnect power and verify the rotation again, then press Stop. The manual also describes tandem use as a first-cut machine: this requires a special adjusting ring. For a side-feed adapter used with a non-Hobart grinder, specify the plate size and type when ordering; for an adjusting ring used with a Hobart grinder, specify the grinder size.

Cleaning & Maintenance

Stop the grinder, disconnect the electrical power and follow lockout/tagout procedures before cleaning or servicing. The operator manual identifies the mixing arm, end ring, knife, plate, cylinder and conveyor screw as parts to remove for cleaning. Use the spanner wrench to loosen the adjusting ring and withdraw the plate, knife and conveyor screw. Inside the hopper, remove the rubber seal at the conveyor-screw drive end by grasping its outer flange or using a dull screwdriver tip.

To remove the mixing arm, loosen the two retaining nuts and remove the pilot-bushing assembly. Rotate and remove the bushing retainer, disengage the arm from the square drive, and lift it out of the hopper. Wash the machine with hot water or steam. If using detergents or sanitizers, follow their manufacturers' instructions. Rinse with clear water and allow the parts to air-dry.

Once the machine is clean and dry, apply a light coat of food-grade mineral oil to the cylinder, adjusting ring, knife, plate and worm. Reassemble the mixing arm, cylinder, end ring, knife, plate and conveyor screw, then reconnect the electrical supply. The manual states that both motor bearings are prelubricated and sealed and require no further lubrication. Heaters for the electric control box and operator panel turn on automatically when the unit is connected to electrical power; the manual says the unit should remain connected except when it is being cleaned or disassembled.

Troubleshooting

• Machine will not run: Check whether the hopper lid is completely closed, the plug is connected to the receptacle, or the circuit breaker has tripped.
• Poor grind result: The manual lists a loose adjusting ring, a dull knife or plate, a knife and plate that are not seated properly, a broken plate stud, or a broken knife as possible causes.
• Foot control malfunction: If the optional foot control has been installed, check that its hose and clamp are firmly secured to the control-box nipple. The manual warns that a loose fit can cause the control to malfunction.

For repairs or adjustments, the manual directs users to contact a local Hobart Service Office. If the foot control is disassembled for cleaning or repair, the manual requires that it be completely reassembled as manufactured before customer use.

Applications

The 4246S is intended for commercial batch mixing and grinding. The operator manual provides grinding rates for fresh boneless beef and pork and describes the machine's use for first and second grinds. A Hobart 4246S equipment listing also identifies beef and pork, poultry, sausage, cheese and dairy processing, pet food, seafood and vegetable processing as related industries. Confirm that the product and required grinding setup are suitable for the specific application. The manual's frozen-meat capability statement applies to the separate 4246HD heavy-duty model, not the 4246S.