The M3RSF80 bevel helical gearbox takes the size 80 industrial housing and arranges it as a right-angle drive: a spiral-bevel first stage turns the motor 90 degrees, and two helical stages on parallel axes finish the reduction. The low-speed shaft is solid steel, machined and keyed for a standard coupling, and the foot mounting carries both the drive weight and the working torque into a prepared foundation.
A Right-Angle Drive That Keeps a Solid Footing
Many buyers reach for a hollow output by habit; the solid-shaft foot build remains the more robust answer wherever the machine is coupled rather than shaft-mounted. A keyed solid shaft keeps the full transmitted torque inside the gear unit and hands it to the coupling in one piece, which suits drive points where the driven machine carries its own pillow blocks - conveyor head pulleys on separate bearings, mill feeders, rotary dryers with independent support rolls. At size 80 the frame sits in the upper half of the band, sized for drives that run loaded for whole shifts.
M3RSF80 Type Code, Position by Position
| M3 | Industrial gear unit family, three geared stages |
| R | Spiral-bevel right-angle input stage (P would keep the motor in line) |
| S | Solid low-speed shaft, keyed coupling seat (H would be a hollow output bore) |
| F | Foot mounting to a foundation (T would give a torque-arm reaction) |
| 80 | Frame size 80 within the horizontal band 50 to 90 |
Each letter answers one layout decision, so the code doubles as a specification sheet. Where the motor must sit beside the machine rather than behind it, the R stage buys that space. Where the coupling already exists and the foundation is poured, S and F finish the description with no further interpretation.
Installations that call for exactly this arrangement:
- Overland and plant-to-plant belt conveyors on continuous duty
- Ball mill feeders and discharge circuits in mining plants
- Rotary dryers and coolers in fertilizer and mineral lines
- Drag chain and scraper conveyors in power stations
- Heavy paddle and plough mixers in process industries
- Screw reclaim conveyors in bulk storage and ports
Why Solid Shaft, Foot Mount at This Torque
The combination appears wherever service teams value inspectability over compactness. The split housing opens for tooth and bearing checks, the coupling can be dial-indicated after any foundation movement, and the spare is a single keyed bushing rather than a shrink-disc kit. Continuous duties benefit most: a conveyor that stops only for planned maintenance cannot afford an alignment regime that depends on the machine shaft, and a foot-mounted solid output simply does not depend on it.
Drawings, Selection and Delivery
WGT issues the industrial range catalogue and the size 80 outline drawing as PDFs, so shaft height, foot pattern, coupling seat and motor interface can be verified against the installation before any commitment. Send the driven machine, motor power and speed, target output speed and the daily duty profile; the selection is confirmed with a rated-torque check against the service factor and a written quotation follows. Units are factory-tested and ship in an export wooden crate with a one-year warranty.
Questions We Hear Most Often
How do I know when the unit needs maintenance?
Beyond routine oil checks, watch for oil weeping at the seals, unusual noise or vibration, and any rise in housing temperature. A seal kit is inexpensive; catching a weeping seal early avoids damage to the bearings and gears.
Which mounting positions can be used?
The unit can be installed in M1 to M6 positions - floor, wall or ceiling. The oil level plug is repositioned for the position you order, so state it up front and the unit is filled and labelled correctly at the works.
Can I reuse my existing couplings and foundations?
Yes. Centre distances, shaft dimensions and flange bolt patterns follow the common industry standards, so couplings, guards and foundations do not have to be redesigned. Send the nameplate details and we confirm the equivalent frame in writing.
Choosing the Right Frame Size
| Model | Centre distance | Output | Typical duty |
|---|
| M3PSF50 | size 50 | solid shaft, foot | conveyors, feeders |
| M3PSF60 | size 60 | solid shaft, foot | crushers, mixers |
| M3PSF70 | size 70 | solid shaft, foot | ball mills, shredders |
| M3PSF80 | size 80 | solid shaft, foot | kilns, heavy conveyors |
| M3PSF90 | size 90 | solid shaft, foot | mill and kiln drives |
| M3RSF50 | size 50 | solid shaft, foot, right-angle | inclined conveyors, elevators |
| M3RSF60 | size 60 | solid shaft, foot, right-angle | screw classifiers, feeders |
| M3RHF70 | size 70 | hollow shaft, foot, right-angle | agitators, drum drives |
| M3PHT80 | size 80 | hollow shaft, torque arm, parallel | shaft-mounted conveyors |
| M3RHT90 | size 90 | hollow shaft, torque arm, right-angle | heavy shaft-mounted drives |
One family, two layouts. Choose P for a coaxial-in / parallel-out drive train, R when the motor must turn 90 degrees; then pick the shaft type and mounting style that the machine interface needs.
Selection Example: Rotary dryer drive with coupling
Take a 132 kW motor at 1485 rpm turning a dryer shell drive shaft at 12 rpm. The ratio follows directly: 1485 / 12 = 123.75, so a ratio near i=124 is selected. In this case the solid keyed output meets the dryer girth-gear pinion drive through an inspectable coupling, and the foot mounting anchors the reaction into the foundation. It always comes down to those three figures. Send them over and we confirm the frame, ratio and service factor in writing.
![online gearbox selection system workflow]()
Selection workflow used by our engineers for every quotation.
Real-World Duty Points
Mining slurry pump drive
At a mineral processing site, hollow-shaft reducers drive slurry pump agitators. The hollow bore takes the pump shaft with no coupling, so a pump change-out no longer means re-aligning a separate drive.
Palm oil mill fruit elevator
A palm oil mill powers its fruit elevator with reducers. The humid, oily atmosphere is handled by FKM seals, and the compact frame fits between the steriliser and the threshing drum.
![right angle gearbox duty points overview]()
An overview of the duty points this series is built for.
Get the Selection Checked - Free of Charge
Already picked a model? Use the WGT Motor & Gearbox Online Selection System to turn your motor data into a model number, and we will quote that exact unit within the day.
Send us your calculated model and duty point. We cross-check the ratio, torque and service factor independently and confirm or flag the difference - a free second pair of engineer eyes. Looking for a gearbox for steel mill? Tell us the duty point and we will confirm the model in writing.
