motorize
#22 meat grinder Convert an American Tool Exchange #22 hand meat grinder,
or this   Substitute #22 hand meat grinder,
to a compact, (1/4 HP) motorized grinder. It grinds at the rate of five (5) pounds a minute, hour after hour, and, because of the ball-bearing speed brake, it is very quiet and vibrationless. The speed brake reduces the motor speed of 1,725 rpm to a grinder speed of about 75 rpm. The base is 1" press board, so that the platform will not "flex" during operation, thus preventing belt slippage. The V-belts are tensioned not too tight, however, so that they will slip if you hit a chunk of bone, instead of breaking a grinder part — the motor mount is slotted, and the main base beneath the grinder mounts is slotted, allowing them to slide for proper V-belt tensioning.

The American Tool grinder comes with a 3L & O-Section, 10" flywheel — The design below uses 1/4 hp,1725 RPM motor and a speed break.  It's a machine that should last 100 years.

Motor, Pulley, Speed Brake and V-Belt Specifications:

Motor: Dunlap(Sears & Robuck) AC Motor, 1/4 HP, 1725 RPM, 115 VAC, 5.0 Amps, 60 Hz

Pulleys: Motor shaft = Die Cast 150A 1/2 by 1 1/2" V Belt Pulley;  McMaster Carr 6245k11
Small speed brake pulley = Die Cast 3L & O-Section, 2" OD, 1/2" Bore   McMaster Carr 6245K514
Large speed brake pulley = Chicago Die Casting 400A 1/2 by 4" V Belt Pulley;   McMaster Carr 6245k38
Grinder flywheel = 3L & O-Section 10" comes with grinder.

Belts: Motor to speed brake: 1/2 x 21 V Belt 4L210; McMaster Carr 6191K97
Speed brake to grinder = 3V-Section Rubber Wedge V-Belt, Trade Size 3v425, 42.5" Outer Circle, 21/64" Height. McMaster Carr 6230K21

Speed Brake: Two cast-iron pillow blocks or mandrels to take a 1/2" shaft. I used 1/2" SS for the shaft and ground it flat where the pulley set screws bear, so that even if the set screws loosen a little, the pulleys will not slip. I recommend pillow blocks with ball bearings rather than with sintered bronze bearings. A good source for pillow blocks is The Big Bearing Store    157 S. Parkway E.    Memphis, TN 38106.   Call toll free 866-967-7729

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Top view.
Note: Slap OFF switch in weatherproof box. Grizzly Industrial Inc. H8241

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Motor mount, speed brake base mount, and grinder base mount are slotted to allow adjustment as belts loosen with use.
Base is 1.3" x 8" x 22" fermica covered press board.

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This shot shows the relationship of flywheel, speed brake and motor.

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Detail of the ball-bearing speed brake.
Motor shaft Pulley = Die Cast 150A 1/2 by 1 1/2" V Belt Pulley;  McMaster Carr 6245k11
Large speed brake pulley = Chicago Die Casting 400A 1/2 by 4" V Belt Pulley;   McMaster Carr 6245k38
Small speed brake pulley = Die Cast 3L & O-Section, 2" OD, 1/2" Bore   McMaster Carr 6245K514
Grinder flywheel pulley = 3L & O-Section 10" comes with grinder.
Motor to speed brake V-belt = 1/2 x 21 V Belt 4L210, McMaster Carr 6191K97
Speed brake to grinder V-belt = 3V-Section Rubber Wedge V-Belt, Trade Size 3v425, 42.5" Outer Circle, 21/64" Height.
McMaster Carr 6230K21
This reduces the 1725 RPM of the motor to about 75 RPM at the grinder.
Note: zerk grease fittings for the bearings.

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Pillow Block Close-up

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belt motor Motor to speed brake V-belt.
McMaster Carr 6191K97
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belt flywheel
Speed brake to grinder V-belt
McMaster Carr 6230K21

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assembly
 

Grinder Details