Adjustable Motor-Mounting Bases
Increase energy efficiency in belt-driven systems while reducing wear on your components—these bases allow you to adjust your motor position to reach the proper belt tension. Choose a base that fits the NEMA frame of your motor, which is listed on the nameplate.
Bases for angular adjustment are good for applications with a 20° and greater angle between the motor and driven unit.
Bases for constant-speed applications keep your motor in a fixed position while operating equipment with a constant speed, such as fans. You can only adjust the motor position when your system is off.
Bases for variable-speed applications can move while operating to make up for vibration and varying loads. You can adjust the motor position manually while your system is running.
Bases with automatic tensioning have springs, so they maintain dynamic belt tensioning during operation to help the motor bearings, belts, and pullers last longer. They’re good for changing and challenging workloads, such as rock crushers, and excellent for reducing maintenance needed for re-tensioning.
For technical drawings and 3-D models, click on a part number.
| Style | For Motor NEMA Frame Size | For Max. Motor hp | Mounting Orientation | Max. Adjustment | Tilt Angle | Adjustment Style | Tensioning Type | Lg. | Wd. | Ht. | Each | |
For Linear Adjustment in Constant-Speed Applications | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | 143, 143T | 1 1/2 | Horizontal | 3" | __ | Cap Screw | Manual | 10 1/2" | 7 1/2" | 1 1/8" | 00000000 | 000000 |
| A | 145, 145T | 3 | Horizontal | 3" | __ | Cap Screw | Manual | 10 1/2" | 8 1/2" | 1 1/8" | 00000000 | 00000 |
| A | 182, 182T | 5 | Horizontal | 3" | __ | Cap Screw | Manual | 12 3/4" | 9 1/2" | 1 1/2" | 00000000 | 00000 |
| A | 184, 184T | 7 1/2 | Horizontal | 3" | __ | Cap Screw | Manual | 12 3/4" | 10 1/2" | 1 1/2" | 00000000 | 00000 |
| A | 213, 213T | 10 | Horizontal | 3 1/2" | __ | Cap Screw | Manual | 15" | 11" | 1 3/4" | 00000000 | 00000 |
| A | 215, 215T | 15 | Horizontal | 3 1/2" | __ | Cap Screw | Manual | 15" | 12 1/2" | 1 3/4" | 00000000 | 00000 |
| A | 48 | 3 | Horizontal | 3" | __ | Cap Screw | Manual | 10" | 6 1/4" | 1 1/8" | 000000000 | 00000 |
| A | 56 | 3 | Horizontal | 3" | __ | Cap Screw | Manual | 10 5/8" | 6 1/2" | 1 1/8" | 00000000 | 00000 |
| B | 254, 254T | 20 | Horizontal | 4" | __ | Cap Screw | Manual | 17 3/4" | 15 1/8" | 2" | 00000000 | 000000 |
| B | 256, 256T | 25 | Horizontal | 4" | __ | Cap Screw | Manual | 17 3/4" | 16 7/8" | 2" | 00000000 | 000000 |
| B | 284, 284T | 30 | Horizontal | 4 1/2" | __ | Cap Screw | Manual | 19 3/4" | 16 7/8" | 2" | 00000000 | 000000 |
| B | 286, 286T | 40 | Horizontal | 4 1/2" | __ | Cap Screw | Manual | 19 3/4" | 18 3/8" | 2" | 00000000 | 000000 |
| B | 324 | 50 | Horizontal | 5 1/4" | __ | Cap Screw | Manual | 22 3/4" | 19 1/4" | 2 1/2" | 000000000 | 000000 |
| B | 326 | 60 | Horizontal | 5 1/4" | __ | Cap Screw | Manual | 22 3/4" | 20 3/4" | 2 1/2" | 000000000 | 000000 |
| B | 364 | 75 | Horizontal | 6" | __ | Cap Screw | Manual | 25 1/2" | 20 1/2" | 2 1/2" | 000000000 | 000000 |
| B | 365 | 90 | Horizontal | 6" | __ | Cap Screw | Manual | 25 1/2" | 21 1/2" | 2 1/2" | 000000000 | 000000 |
| B | 404 | 120 | Horizontal | 7" | __ | Cap Screw | Manual | 28 3/4" | 22 3/8" | 3" | 000000000 | 000000 |
| B | 405 | 150 | Horizontal | 7" | __ | Cap Screw | Manual | 28 3/4" | 23 7/8" | 3" | 000000000 | 000000 |
| B | 444 | 200 | Horizontal | 7 1/2" | __ | Cap Screw | Manual | 31 1/4" | 24 5/8" | 3" | 000000000 | 000000 |
| B | 445 | 200 | Horizontal | 7 1/2" | __ | Cap Screw | Manual | 31 1/4" | 26 5/8" | 3" | 000000000 | 000000 |
| B | 447 | 200 | Horizontal | 7 1/2" | __ | Cap Screw | Manual | 31 1/4" | 30 1/8" | 3" | 000000000 | 000000 |
| B | 449 | 200 | Horizontal | 7 1/2" | __ | Cap Screw | Manual | 31 1/4" | 35 1/8" | 3" | 000000000 | 000000 |
For Linear Adjustment in Variable-Speed Applications | ||||||||||||
| C | 48, 56 | 3 | Any Angle | 2 1/8" | __ | Hex Nuts | Automatic | 9 1/2" | 5 7/8" | 1 3/8" | 00000000 | 000000 |
| C | 143, 145 | 5 | Horizontal | 3" | __ | Hex Nuts | Automatic | 11 11/16" | 8 1/4" | 1 7/8" | 000000000 | 000000 |
| C | 182, 184 | 8 | Horizontal | 3" | __ | Hex Nuts | Automatic | 14 1/16" | 9 3/8" | 2 1/8" | 000000000 | 000000 |
| C | 213, 215 | 12 | Horizontal | 3 1/2" | __ | Hex Nuts | Automatic | 16 3/8" | 11 3/8" | 2 9/16" | 000000000 | 000000 |
| C | 254, 256 | 25 | Horizontal | 4" | __ | Hex Nuts | Automatic | 19 1/2" | 15 1/4" | 3 1/8" | 000000000 | 00000000 |
| C | 284, 286 | 35 | Horizontal | 5" | __ | Hex Nuts | Automatic | 22 1/8" | 16 3/4" | 3 3/16" | 000000000 | 00000000 |
| D | 48, 56 | 3 | Any Angle | 5 7/8" | __ | Hand Crank | Manual | 13 1/8" | 6 1/4" | 3" | 0000000 | 000000 |
| E | 48, 56, 56H, 66, 143T, 145T, 182, 184, 203 | 2 | Horizontal, Vertical | 8" | __ | Hand Crank | Manual | 18 1/8" | 8" | 3 1/4" | 0000000 | 000000 |
For Angular Adjustment in Constant-Speed Applications | ||||||||||||
| F | 56, 143, 145 | 3 | Any Angle | __ | 0° to 30° | Pivot | Manual | 15" | 8 3/8" | 3 1/2" | 000000000 | 000000 |
| F | 182, 184, 213, 215 | 12 | Any Angle | __ | 0° to 30° | Pivot | Manual | 16 3/4" | 11 7/8" | 3" | 000000000 | 000000 |
| F | 254, 256, 284, 286 | 35 | Any Angle | __ | 0° to 30° | Pivot | Manual | 20" | 16 5/8" | 3 5/8" | 000000000 | 000000 |
For Angular Adjustment in Variable-Speed Applications | ||||||||||||
| G | 48, 56 | 3 | Any Angle | __ | 0° to 30° | Hand Crank | Manual | 12 1/2" | 5 7/8" | 3 1/2" | 0000000 | 000000 |