Leeson 3/4 HP Motor vs. Stepper Motor + Driver: A TCO Comparison for Small Conveyors and Indexing

I am a procurement manager at a 90-person packaging-equipment integrator. I have managed our motion and motor budget—about $310,000 annually—for six years, negotiated with 20+ vendors, and logged every order in our cost tracking system. In Q1 2025, we reviewed two drive options for a family of small conveyors and indexing stations: a Leeson 3/4 HP single-phase induction motor with a fixed-ratio gearbox, and a stepper motor + driver package with a planetary reducer. The sticker prices looked close. The TCO did not. Here is the comparison framework I use now: upfront integration, nameplate and spec risk, control performance, maintenance and downtime, and gearbox/gear type. I will compare them dimension by dimension instead of pretending one is always better.

Comparison Framework: What Actually Matters for a 3/4 HP Conveyor or Indexer

Most quotes focus on the motor or the stepper motor driver. That is the wrong unit of analysis. The real question is the drive train: motor, driver or starter, gearbox, mounting, controls, spare parts, and the cost of a wrong guess. For our small conveyors, the load was 40-70 lb, speed was either constant or indexed 12-18 times per minute, and the panel had single-phase 115/230V available. That pushed us to compare a Leeson 3/4 HP motor against a stepper package. If your panel has three-phase power, a VFD and three-phase motor may be a better third option. If you need closed-loop positioning, neither of these may be right.

Dimension 1: Upfront Cost and Integration

Leeson 3/4 HP single-phase induction motor

In Q1 2025, we collected quotes from three distributors for a Leeson 3/4 HP single-phase motor. Unit pricing landed between $248 and $329 each, before the gearbox, starter, and mounting plate. A simple spur gearbox added $180-$260. A manual starter or contactor added $45-$90. Installation was mostly mechanical and electrical: match the frame, wire the capacitor and centrifugal switch correctly, align the gearbox, and set the overload. No programming. No tuning. The hidden cost is spec risk—more on that below.

Stepper motor + driver

A NEMA 23 stepper motor with a matching driver and planetary gearbox quoted between $210 and $460. That looks competitive. Then the controls engineering starts. We needed a pulse generator or PLC output, microstepping setup, acceleration ramps, homing sensor, and sometimes a resonance damper. One application needed 6 hours of controls tuning. At our loaded engineering rate, that was $720. The stepper motor driver itself was cheap; the system around it was not.

Upfront conclusion: If you already have a PLC and an engineer who knows steppers, the stepper package can be cheaper up front. If you are replacing a dumb conveyor drive and want bolt-on simplicity, the Leeson 3/4 HP motor usually wins.

Dimension 2: Leeson Motor Nameplate and Spec Risk

The Leeson motor nameplate is not decoration. It is your last chance to avoid a costly return. I learned this the hard way. We did not have a formal nameplate verification process for incoming motors. Cost us when a 3/4 HP Leeson motor arrived with a 56C frame and our existing bracket was 56. The motor was fine. The mounting was not. We spent $310 on a new bracket and two days of schedule recovery. The third time that kind of mismatch happened, I finally created a one-page checklist.

On a Leeson motor nameplate, verify these fields before you order: HP, RPM, voltage, phase, frequency, frame, enclosure, service factor, ambient temperature, insulation class, duty, and efficiency. For a Leeson 3/4 HP single-phase induction motor, the phase and voltage fields are especially important. A 115/230V motor can be wired for either, but the nameplate connection diagram must match your panel. If the nameplate says 208-230V, do not assume it will run happily on 208V single-phase without checking the connection diagram and the actual supply.

NEMA MG 1 covers nameplate marking conventions for motors, including HP, voltage, phase, frequency, RPM, frame, service factor, insulation class, and duty. Source: NEMA MG 1, current edition; verify with your Leeson catalog and the specific nameplate before ordering.

Stepper systems have their own spec sheet: driver current rating, bus voltage, motor inductance, step angle, holding torque, and maximum speed. There is no universal nameplate convention like NEMA MG 1. That means more variation between vendors, and more chances for a mismatch. In our review, two stepper motor drivers with the same NEMA 23 motor had 18% different usable torque at 600 RPM because of inductance differences. The datasheets did not make that obvious.

Dimension 3: Control Performance and Application Fit

A single phase induction motor is a constant-speed device. It starts, runs at roughly synchronous speed minus slip, and keeps going. For a continuous conveyor, that is a feature. For indexing, it is a limitation unless you add a clutch, brake, or mechanical indexer. The Leeson 3/4 HP motor had good starting torque for its size and was simple to reverse with a drum switch. It did not need a driver. It also did not care about microstepping, acceleration curves, or lost steps.

A stepper motor + driver is a positioning device. It moves in discrete steps, holds position when stopped, and can change speed and direction from a controller. For a 12-stop-per-minute indexing station, it was the better fit. But here is the surprise: the stepper did not win on torque at speed. At 900 RPM, its torque had dropped enough that we had to oversize the motor or change the gear ratio. The Leeson 3/4 HP motor held its rated speed and torque all day. If your process needs continuous high-speed conveying, a stepper may be the wrong tool.

Control conclusion: Choose the Leeson single-phase induction motor for constant speed, simple reversing, and high continuous duty. Choose the stepper motor + driver for precise indexing, low-speed holding torque, and programmable motion. If you need both speed and positioning, price a servo before you force either option.

Dimension 4: Maintenance, Downtime, and Hidden Costs

I once saved $180 by buying a generic stepper motor driver instead of the matched brand-name driver. It failed in month seven. The replacement was covered, but the line was down for five hours. Our downtime cost that quarter was $280 per hour. Net loss: $1,400, plus the expedited shipping. That is the penny-wise, pound-foolish tax.

The Leeson motor had its own maintenance profile: bearings, capacitor, and centrifugal switch on some single-phase designs. But those are known items. A local motor shop can repair them, and the nameplate gives the exact replacement specs. The stepper driver is an electronic assembly. When it fails, you often replace the board, not repair it. Spares are cheaper, but diagnostics take longer because the failure can look like a mechanical problem, a tuning problem, or a controller problem.

What most people do not realize is that the first quote for an ongoing motor or driver program is almost never the final price. Distributors build in buffer for lead time and support. Once you have a documented order history, there is usually room to negotiate spare parts, training, or freight. We now ask for a TCO sheet from every vendor, not just a unit price.

Dimension 5: Gearbox and Which Gear Is Most Likely to Use a Spur Gear

This is where the Leeson 3/4 HP motor and the stepper package often get separated. A spur gear is most likely to be used in a parallel-shaft gearbox, especially a single-reduction or double-reduction reducer on a constant-speed induction motor. Spur gears are simple, efficient, and inexpensive to manufacture. They are common in conveyor reducers, agitators, and packaging drives where noise is acceptable and cost matters. If you need quieter operation, helical gears are more likely. If you need high torque density in a compact package, planetary gears are more likely.

So when someone asks, which gear is most likely to use a spur gear, the practical answer is: a parallel-shaft gearbox on a Leeson 3/4 HP single-phase induction motor running a constant-speed conveyor. That combination is straightforward to source, easy to replace, and usually the lowest TCO for simple conveying. A stepper motor + driver often uses a planetary reducer because the package needs low backlash and compact size for indexing. That is a different job, and it costs more.

Selection Advice: When to Choose Which

Choose the Leeson 3/4 HP single-phase induction motor when you have single-phase power, constant speed, simple on/off or reversing control, continuous duty, and a tolerance for some gear noise. It is the better fit for basic conveyors, fans, pumps, and mixers where the Leeson motor nameplate gives you a known, repeatable spec.

Choose the stepper motor + driver when you need precise positioning, repeated indexing, low-speed torque, programmable motion, and you have controls support. It is the better fit for pick-and-place indexes, small rotary tables, and dosing stations. Be honest about the engineering time and the risk of lost steps.

Do not choose either if you need closed-loop torque control at high speed, washdown protection, or explosion-proof ratings. That is not a limitation of the brands. It is a limitation of the technology. This comparison works for about 80% of the small conveyor and indexing jobs we see. If you are in the other 20%, get a servo or a specific severe-duty motor quote before you standardize.

There is something satisfying about finally getting a drive-train standard that holds up. After six years of invoice tracking, the best part is not the lowest unit price. It is fewer emergency purchases, fewer nameplate surprises, and a TCO number you can defend in the next budget review.