Raymarine Rotary Drive Type 2 - 12V Autopilot Drive Unit
Raymarine Rotary Drive Type 2 - 12V Autopilot Drive Unit — Product description
The Raymarine Rotary Drive Type 2 - 12V (MPN M81136) is the heavy-duty autopilot drive unit for power and sailboats with cable or rod steering systems that can be driven from the helm position through a chain and sprocket. Type 2 is the larger of Raymarine's two rotary drive variants - rated for vessels up to 44,000 lbs (20,000 kg) maximum displacement. Smooth, powerful, quiet autopilot-controlled steering through the boat's existing chain-and-sprocket steering linkage. 34 Newton-meter peak output torque. 33 RPM maximum shaft speed. 10-second hard-over time (no load) - fast enough for responsive autopilot operation, slow enough that the drive doesn't overrun the steering system. 60-84 watt power consumption (5-7 amps at 12V). Works with the Raymarine ACU-400 Autopilot Control Unit (corepack sold separately) to form a complete autopilot system. Optional drive sprockets and modifications to the steering chain system may be required for some boats. 2-year limited warranty.
The Raymarine Rotary Drive Type 2 - 12V is the heavy-duty autopilot drive unit in Raymarine's rotary drive product line - designed specifically for power and sailboats with cable or rod steering systems that can be driven from the helm position through a chain and sprocket linkage. This is the actuator that physically turns the boat's steering wheel under autopilot control, working through the same chain-and-sprocket system that the helmsman uses manually. For boats with the right steering configuration (chain-and-sprocket compatible), the rotary drive is meaningfully simpler and quieter than hydraulic alternatives.
Type 2 - the heavy-duty variant. Raymarine offers two rotary drive types. Type 1 is the smaller variant for lower-displacement boats. Type 2 is the heavy-duty variant rated for up to 44,000 lbs (20,000 kg) maximum vessel displacement - sized for typical mid-large sailboats (40-60 ft cruising sailboats with sufficient internal volume to reach those displacements) and substantial power vessels with chain-and-sprocket steering. The higher output torque of Type 2 vs Type 1 is what handles the larger steering loads of bigger boats. using Type 1 on a Type 2-sized boat means the drive can't reliably steer in heavy conditions. Match drive type to vessel displacement - oversized is wasteful, undersized is dangerous.
For cable and rod steering systems. The rotary drive specifically works with cable or rod-type steering systems - the kind where the helm wheel turns a shaft that drives the steering linkage via mechanical means. For boats with hydraulic steering (most modern recreational powerboats over 25 feet), the rotary drive is NOT the right drive unit - hydraulic systems need a hydraulic pump drive (Raymarine's SmartPump line). Verify your boat's steering system type before ordering this drive. Cable / rod steering is most common on sailboats with chain-and-sprocket helm pedestals, classic powerboats with cable steering, and some specialty vessels.
Chain and sprocket interface. The drive mounts to the boat's steering chain system via a sprocket on the drive output shaft - the same chain that the helm wheel drives. The autopilot's commands to the drive get translated into chain pulls / pushes that turn the steering. The interface is mechanical and direct - no hydraulics, no separate steering actuators, just an additional drive sprocket on the existing chain. The install requires breaking into the existing chain run to add the drive sprocket and the drive unit mount, which is moderately involved but works on virtually any chain-and-sprocket steering system.
34 Newton-meter peak output torque. The drive develops 34 Nm peak torque at the output shaft - enough to handle the steering loads of 44,000-lb-displacement vessels in normal sea conditions. For reference, 34 Nm is roughly 25 ft-lbs at the output shaft - a substantial mechanical advantage when multiplied through the chain-and-sprocket ratio. The output torque rating is what determines maximum vessel displacement. bigger boats need more torque to overcome the hydrodynamic loads on the rudder.
33 RPM maximum shaft speed. The drive's output shaft turns at up to 33 RPM at full speed. Through the chain-and-sprocket ratio (typical 2:1 to 4:1 reduction from drive to helm), this works out to 8-16 RPM at the helm wheel - fast enough for responsive autopilot operation, slow enough that the drive doesn't overrun the steering system or create dangerous wheel speeds. The recommended hard-over time (full lock to full lock with no rudder load) is 10 seconds.
Smooth, powerful, quiet operation. The Raymarine rotary drive design provides smooth, powerful autopilot steering with notably quiet operation - meaningfully quieter than older drive units that announced their operation with audible motor whining. The quiet operation matters on sailboats especially, where the autopilot often runs for extended periods during passages and audible noise becomes annoying. For typical sailboat use (autopilot running overnight on passage), the quiet drive is the kind of detail you appreciate.
60-84 watt power consumption. At typical steering loads, the drive consumes 60-84 watts (5-7 amps at 12V). The variability covers the range from light steering loads (calm conditions, balanced sail trim) up to heavy loads (rough conditions, unbalanced trim, autopilot working hard to hold heading). Plan the power supply for 84W continuous to ensure the drive operates at full capability under all conditions - undersized power supply causes the drive to operate at reduced output, which translates to lazy autopilot response.
Works with ACU-400 Autopilot Control Unit. The rotary drive is one component of a complete Raymarine autopilot system - it needs the ACU-400 Autopilot Control Unit (sold separately) as the brain that commands the drive. The ACU-400 reads the boat's heading (from the autopilot's heading sensor / magnetic compass), computes the steering command, and sends the drive command to the rotary drive. The ACU-400 also handles operator interface integration (autopilot control head or chartplotter integration), communication with the broader Raymarine SeaTalk network, and the heading-control algorithm that determines how aggressively the drive corrects course.
What you need for a complete autopilot. For a complete working autopilot system, you need: this rotary drive (the actuator), the ACU-400 control unit (the brain - sold separately), a heading sensor (typically a magnetic compass or fluxgate sensor - some ACU-400 variants include this, some don't), an operator interface (either a dedicated autopilot control head like the p70R, or chartplotter integration via SeaTalk network), and the appropriate cabling between all components. Plan the complete system at install time, not piece by piece.
Drive sprockets - may need separate purchase. The rotary drive includes a standard drive sprocket sized for typical Raymarine pedestal applications. For non-standard installations or specific boat configurations, optional drive sprockets may be required to match the boat's existing chain system. Modifications to the steering chain system (adding chain length, repositioning idlers, etc) may also be needed depending on where the drive mounts relative to the existing chain run. Consult with a Raymarine authorized dealer or Raymarine product support for your specific install - the dealer / support can advise on sprocket selection and modification requirements before you commit to the install.
Power and sailboat compatibility. Despite often being thought of as a sailboat autopilot drive, the Rotary Drive Type 2 works on power vessels with chain-and-sprocket steering as well. Some classic powerboats, some specialty vessels, and some older designs use chain-and-sprocket steering rather than the now-dominant hydraulic systems. For those vessels, the rotary drive is the right autopilot drive choice - and the same Type 2 unit handles them up to the 44,000 lb displacement limit.
Install considerations. Rotary drive install is moderately involved - requires marine mechanical expertise to break into the existing chain run, add the drive sprocket, mount the drive unit in the appropriate location relative to the chain, and configure the chain tension properly. The install location needs sufficient clearance for the drive body and the mounting bracket plus access for service. For owners not experienced with marine mechanical work, professional install at a marine yard is the right call. Total install time is typically 8-16 hours of professional labor depending on boat complexity.
Limited 2-year warranty. Raymarine backs the Rotary Drive Type 2 with a 2-year limited warranty against manufacturing defects under normal recreational use. Service through the Raymarine warranty network. Save the receipt and original packaging if practical for warranty service. The rotary drive's mechanical simplicity (vs hydraulic alternatives with their seals, fluids, and pressure failure points) means warranty issues are rare - the drive is designed to operate for many years without service issues under normal conditions.
Key Features
- Raymarine Rotary Drive Type 2 - 12V autopilot drive unit
- For power and sailboats with cable / rod steering systems driven through chain and sprocket
- Type 2 (heavy-duty variant) - up to 44,000 lbs (20,000 kg) maximum vessel displacement
- 34 Newton-meter peak output torque
- 33 RPM maximum shaft speed
- 10-second recommended hard-over time (no load)
- 60-84 watt power consumption (5-7 amps at 12V)
- 12V DC operation
- Smooth, powerful, quiet autopilot steering operation
- Mechanical interface to existing chain-and-sprocket steering - no hydraulics required
- Works with Raymarine ACU-400 Autopilot Control Unit (sold separately)
- Standard drive sprocket included (optional sprockets may be needed for specific configurations)
- NOT compatible with hydraulic steering systems (use SmartPump line for hydraulic)
- NOT compatible with mechanical-only steering without chain and sprocket
- 2-year limited warranty
- Manufacturer Part Number M81136 / UPC 023193811369
Why Buy from NVN Marine
- Authorized Raymarine reseller, full manufacturer warranty
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Technical specifications
| Title | Raymarine Rotary Drive Type 2 - 12V Autopilot Drive Unit |
|---|---|
| Brand | Raymarine |
| Manufacturer Part Number | M81136 |
| UPC | 023193811369 |
| Type | Rotary autopilot drive unit |
| Variant | Type 2 (heavy-duty) |
| Steering System Compatibility | Cable or rod steering driven via chain and sprocket |
| Maximum Vessel Displacement | 44,000 lbs (20,000 kg) |
| Input Voltage | 12V DC |
| Peak Output Torque | 34 Newton-meter |
| Maximum Shaft Speed | 33 RPM |
| Recommended Hard-Over Time | 10 seconds (no load) |
| Power Consumption | 60-84 watts (5-7 amps at 12V) |
| Required Corepack | Raymarine ACU-400 Autopilot Control Unit (sold separately) |
| Heading Sensor | Required (sold separately - some ACU-400 variants include) |
| Operator Interface | p70R autopilot control head OR chartplotter via SeaTalk (sold separately) |
| Drive Sprocket | Standard sprocket included (optional sprockets available for specific configurations) |
| Steering Modifications | May be required for some installations |
| NOT Compatible With | Hydraulic steering (use SmartPump line), non-chain mechanical steering |
| Boat Type | Power AND sailboats with chain-and-sprocket steering |
| Operation | Smooth, powerful, quiet |
| Mechanical Design | No hydraulics, no fluid seals - low-maintenance long-life |
| Warranty | 2-year limited |
Frequently asked questions
Will it work on my boat?
The Rotary Drive Type 2 works only on boats with cable or rod steering systems that can be driven from the helm position through a chain and sprocket linkage. Typical on sailboats with chain-and-sprocket helm pedestals, some classic powerboats with cable steering, and some specialty vessels. NOT compatible with hydraulic steering systems (use Raymarine's SmartPump line for hydraulic). NOT compatible with mechanical steering that doesn't use a chain-and-sprocket interface. Verify your boat's steering system type before ordering.
Type 1 vs Type 2 - which do I need?
Match drive type to vessel displacement. Type 1 is the smaller variant for lower-displacement boats. Type 2 (this unit) is rated for vessels up to 44,000 lbs (20,000 kg) maximum displacement - sized for typical mid-large sailboats (40-60 ft cruising) and substantial power vessels. Using Type 1 on a Type 2-sized boat means the drive can't reliably steer in heavy conditions. Using Type 2 on a Type 1-sized boat is wasteful but works. Match drive type to your boat's actual displacement.
What else do I need for a complete autopilot?
This drive is one component. For a complete working autopilot system, you need: this rotary drive (the actuator), the ACU-400 Autopilot Control Unit (the brain - sold separately), a heading sensor (magnetic compass or fluxgate - some ACU-400 variants include this, some don't), an operator interface (autopilot control head like p70R or chartplotter integration via SeaTalk network), and appropriate cabling. Plan the complete system at install time, not piece by piece - mixing incompatible components doesn't work.
What's the ACU-400?
The Autopilot Control Unit - the brain of the autopilot system that this drive works with. The ACU-400 reads the boat's heading from the heading sensor, computes the required steering correction, and commands the rotary drive to execute that correction. Sold separately. For a complete autopilot, you need this drive AND the ACU-400 AND a heading sensor AND an operator interface.
Will the chain-and-sprocket interface fit my steering?
The drive includes a standard drive sprocket sized for typical Raymarine pedestal applications. For non-standard installations, optional drive sprockets may be required to match your boat's specific chain system. Modifications to the steering chain (adding chain length, repositioning idlers, mounting the drive in the available space) may also be needed depending on your boat's configuration. Consult with a Raymarine authorized dealer or Raymarine product support for your specific install before committing to the install.
What's hard-over time?
The time the autopilot drive takes to move the steering from full lock one way to full lock the other way with no rudder load. Recommended hard-over time for this drive is 10 seconds. Why this matters: too fast and the drive overruns the steering system creating dangerous wheel speeds. Too slow and the autopilot can't respond quickly enough to course corrections, particularly in challenging conditions. The 10-second target is the sweet spot for typical chain-and-sprocket systems on Type 2-sized vessels.
How much power does it draw?
60-84 watts (5-7 amps at 12V) depending on steering load. Light conditions (calm water, balanced trim) are at the 60W end. heavy conditions (rough water, unbalanced trim, autopilot working hard) are at the 84W end. Plan the power supply for 84W continuous to ensure the drive operates at full capability under all conditions. Undersized power supply causes the drive to operate at reduced output, which translates to lazy autopilot response.
Why is it quieter than older drives?
Raymarine's current rotary drive design specifically targets quiet operation - the motor housing, gear train, and mounting are all engineered to minimize audible noise during operation. Older drive units announced their operation with audible motor whining that became annoying during extended autopilot use. The quiet operation matters on sailboats especially, where the autopilot often runs for extended periods during passages.
Why mechanical rotary vs hydraulic?
Two main reasons. Mechanical simplicity: no hydraulic fluids to leak, no seals to fail, no pressure components to degrade over time. The rotary drive operates for many years without service issues under normal conditions. Steering system compatibility: rotary drive works with the existing chain-and-sprocket steering on boats that have it - no need to convert the steering system to hydraulic. For boats designed with chain-and-sprocket steering, rotary is the natural autopilot choice.
How does it install?
Moderately involved install. Break into the existing chain run to add the drive sprocket. Mount the drive unit in the appropriate location relative to the chain (typically near the helm pedestal). Configure chain tension. Wire 12V power from the boat's electrical system through an appropriate circuit breaker. Connect the drive control cable to the ACU-400 control unit. Test operation thoroughly. Total professional install time is typically 8-16 hours depending on boat complexity. For owners not experienced with marine mechanical work, professional install at a marine yard is the right call.
How big does the install location need to be?
The drive needs sufficient clearance for the drive body, the mounting bracket, and access for service. Specific dimensions depend on your boat's layout - typical install requires roughly 12 x 12 x 8 inches of clear space near the steering chain run. Service access for the drive belt and the mounting bolts adds to the required space. Consult the Raymarine install documentation for your specific configuration before committing to a mount location.
What's the warranty?
Limited 2-year warranty against manufacturing defects under normal recreational use. Service runs through the Raymarine warranty network. Save the receipt and original packaging if practical for warranty service. The rotary drive's mechanical simplicity (vs hydraulic alternatives with their seals, fluids, and pressure failure points) means warranty issues are rare.