4246

Overview

The Hobart 4246 is a commercial mixer-grinder for processing meat in batches. Its hopper holds up to 140 lb, depending on the type of product, and its separate mixing and grinding drives let an operator mix product in the hopper before grinding or run mixing and grinding together. A full-length conveyor screw feeds product toward the grinding end, where Hobart’s Wedge cylinder helps draw meat from the hopper into the cylinder.

The 4246 is available in standard and heavy-duty configurations. The standard 4246S uses a 5 HP grind motor and a 1 HP mix motor. The 4246HD uses a 7.5 HP grind motor and a 1 HP mix motor for mixed fresh and frozen applications. The installation and operation manual identifies the HD unit as suitable for frozen meat tempered to 26°F or higher, in flake or stick form. Confirm the machine’s model and data plate before matching parts or electrical service.

Key Features

• Separate drives: A 1 HP motor drives the mixing arm; a separate grind motor drives the conveyor screw.
• Wedge cylinder grinding end: The #46 Wedge cylinder draws product through its large upper opening and is sized for #32 knives and plates.
• Batch capacity and output: The hopper holds up to 140 lb, depending on product. Published rates are 55–60 lb per minute for fresh boneless beef and 60–65 lb per minute for fresh pork under the specified plate and cutting conditions.
• Operator controls: Up-front controls include MIX START, MIX/GRIND START and STOP. Electrical controls include waterproof start and stop switches, magnetic contactors and dual motor overload protection.
• Lid interlock: Opening the hopper lid cuts power to the motors. The lid must be in its operating position before the grinder can start.
• Removable components: The mixing arm, conveyor screw, cylinder, end ring, knife, plate and conveyor screw drive-shaft seal can be removed for cleaning.
• Hopper access: The hopper lid can be configured for right- or left-side loading.

Specifications

• Product: Hobart 4246 Mixer-Grinder.
• Configurations: 4246S standard, 5 HP grind motor and 1 HP mix motor; 4246HD heavy duty, 7.5 HP grind motor and 1 HP mix motor. The parts manual also identifies machine serial/model designations ML-134220 and ML-134221, respectively, and lists prior MLs.
• Motor total: The operation manual states 6 HP total for the 4246S and 8.5 HP total for the 4246HD.
• Hopper capacity: Up to 140 lb, depending on product.
• Fresh boneless beef grinding rate: 55–60 lb per minute, first or second cutting through a 1/8 in plate.
• Fresh pork grinding rate: 60–65 lb per minute, second cutting through a 3/16 in plate.
• Frozen product for the 4246HD: Tempered to 26°F or higher; product may be in flake or stick form.
• Grinding end: #46 Wedge cylinder; sized for #32 knives and plates. Knife and plate assemblies are not included with the unit but are optionally available.
• Mixing arm speed: 23 rpm.
• Conveyor screw speed: The product specification lists 194 rpm; the 2002 operation manual lists 216 rpm. Refer to the documentation and data plate for the specific machine.
• Electrical connection: The standard-machine specification lists an 8 ft cord and plug. The published general specification lists 208/60/3 and 380–415/50/3; a later specification lists 208/60/3. Verify the individual machine data plate and electrical configuration.
• Electrical controls and safety: Waterproof start and stop switches, magnetic contactors, dual motor overload protection, foot-switch operation capability and an electrical hopper-lid interlock.
• Finish and materials: Glass bead finished stainless steel hopper; stainless steel panels around the base assembly and motors; tinned mixing arm and conveyor screw; stainless steel end ring and cylinder; nickel chrome plated legs.
• Standard legs: Non-adjustable stationary legs. Caster options include non-adjustable legs with casters and adjustable legs with casters in short and long height ranges.
• Caster height ranges: Short adjustable casters: 9 3/4–12 1/4 in from floor to base of frame. Long adjustable casters: 12 3/8–17 1/2 in from floor to base of frame. Non-adjustable caster legs are listed as 7 5/8 in.
• Dimension-chart values: The published chart labels dimensions A, B, D and F. Standard and caster: A 7 15/16 in, B 24 7/16 in, D 49 15/16 in, F 71 5/16 in. Short adjustable caster, minimum: A 10 1/16 in, B 26 9/16 in, D 52 1/16 in, F 73 7/16 in. Short adjustable caster, maximum: A 12 1/4 in, B 28 3/4 in, D 54 1/4 in, F 75 5/8 in. Long adjustable caster, minimum: A 12 11/16 in, B 29 3/16 in, D 54 11/16 in, F 76 1/16 in. Long adjustable caster, maximum: A 17 1/2 in, B 34 in, D 59 1/2 in, F 80 7/8 in.
• Options and accessories listed: Pneumatic foot switch; caster leg options; and #32 Stay-Sharp knife and plates.

Installation & Requirements

Check the machine data plate, located under the hopper on the right, to verify that the electrical supply matches the machine. The mixer-grinder is supplied with a cord and plug and requires an appropriately sized, grounding-type receptacle. Electrical and grounding connections must comply with applicable national and local electrical codes. The published voltage configurations differ across specification documents, so use the data plate for the particular unit rather than assuming a voltage or phase.

After unpacking, check for shipping damage. The manual says to retain the packaging and contact the carrier within 15 days of delivery if damage is found. Remove the packing box by loosening the four bolts through the wooden skid. The legs are shipped separately and require a 15/16 in socket; the manual specifies tightening them to 50 ft-lb. 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 already assembled. Remove the shipping plate and rubber spacer at the chopping end and install the #32 knife and plate assembly, which is not supplied.

Level the mixer-grinder front to back and side to side by loosening the two set screws on the caster or leg shaft, then tighten both set screws when level. For a pneumatic foot switch, the manual describes routing its hose through the knockout beneath the lower front frame rail, securing the hose to the control-box nipple with its clamp and reinstalling the lower front panel. Avoid kinking the hose and ensure the hose and clamp are firmly secured. After installation, check that the mixing arm and worm rotate counterclockwise when viewed from the front. If they do not, disconnect power, interchange any two supply leads at the receptacle, reconnect power and verify rotation. Electrical work must follow applicable codes.

Operation

Controls and modes

• MIX START: Starts the mixing arm without operating the hopper conveyor screw.
• MIX/GRIND START: Operates both the mixing arm and conveyor screw for mixing and grinding.
• STOP: Stops all operations.
• FOOT SWITCH ON/OFF: In the ON position, the foot switch operates Mix/Grind mode only, and the MIX START and GRIND START buttons are inoperable. In the OFF position, the buttons are operable. With the foot control ON, holding STOP stops the machine for as long as the button is held down.

Before using the grinding cylinder, take it apart and wash it thoroughly. The Wedge cylinder is marked TOP and BOTTOM; fit it with TOP visible. Hand-tighten the end ring—overtightening can damage the unit. Do not use a plate with a hole size smaller than 3/32 in. The knife and plate must be sharp and true for proper cutting. The manual directs operators to rub tallow or mineral oil over their cutting surfaces for preliminary lubrication.

For a first grind, fill the hopper, close and latch the lid, then press MIX/GRIND START. Press STOP to stop grinding. Do not overfill: the manual warns that overfilling can bend the hopper lid and may cause the interlock to open the electrical circuit. For a second grind, fill the hopper and close and latch the lid. Press MIX START and mix for the desired time, then press STOP. Press MIX/GRIND START to grind and press STOP to stop, or use the optional foot switch. During Mix-Only operation the mixing arm runs while the hopper conveyor screw does not; during Mix/Grind operation, continuous self-feeding occurs along with grinding.

The hopper lid is arranged for right- or left-side loading. To close it, lift the locking catch on the front hinge while holding the lid with the other hand. When using the 4246 as a first-cut machine in tandem, the manual specifies a special adjusting ring. Side-feed adapters for non-Hobart grinders require the plate size and type to be specified when ordered.

Cleaning & Maintenance

Disconnect electrical power and follow lockout/tagout procedures before cleaning or servicing. Stop the grinder and unplug it before cleaning. Remove the mixing arm, end ring, knife, plate, cylinder and conveyor screw. 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 mixing arm pilot bushing assembly. Rotate and remove the bushing retainer, disengage the arm from the square drive, then lift it out of the hopper. Wash the machine with hot water or steam. If using detergents or sanitizers, follow their manufacturer’s instructions; rinse with clear water and allow the machine to air-dry. When 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 electrical power.

The mixing arm, conveyor screw, cylinder and conveyor screw drive-shaft seal are removable for cleaning. Both motor bearings are prelubricated and sealed and require no further lubrication. The machine’s electric control-box and operator-panel heaters keep the controls dry and turn on automatically when the unit is electrically connected. The manual says the machine should remain connected except when it is being cleaned or disassembled. If oil loss is observed, check the oil levels of both transmissions before operation and contact a local Hobart Service Office.

Troubleshooting

• Machine will not run: Check whether the hopper lid is completely closed, whether the plug is disconnected from the receptacle, or whether 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: For installation, the manual cautions that a loose hose or clamp at the control-box nipple can cause the foot control to malfunction. If the foot control is disassembled for cleaning or repair, it must be completely reassembled as manufactured before customer use.
• Repairs or adjustments: The operation manual directs users to contact a local Hobart Service Office for repairs or adjustments.

Applications

The 4246 suits commercial meat-preparation work where operators need to mix and grind batches through a #32 knife-and-plate assembly. The documented uses include grinding fresh boneless beef and fresh pork at the specified plate sizes and cutting stages. The 4246HD is specified for mixed fresh and frozen meat tempered to 26°F or higher, including flake or stick product. The hopper capacity and published rates make the model relevant to butcher-shop production, deli meat preparation and commercial kitchens that process fresh meat in batches.