Autohelm Type 2 Linear Drive (12V)

[Helimech]

Does anyone know how to test one of these linear drives. Can I just put 12 volts to the clutch wires to engare the clutch and then put 12 volts and ground to the big wires to run the ram in and out? Thanks for any help.

[msoneji]

Hi Helimech,

Here are some steps to test the drive unit:

1. Without connecting any power the piston should freely come in and out. This allows for you to use your steering when auto pilot is off. If this does not move freely I would think the drive is shot.
2. As soon as you apply 12V to the clutch the piston should lock up and no longer move freely as before. If it still moves the clutch is not operating.
3. Keep the connection to the clutch in place while rod is half-way out and then as you apply the 12v dc to the drive connections the piston should move in and out.

Please report back if the procedure helps you and what you find. Cheers.

[GordMay]

✓ Thanks for sharing those clear & concise instructions msoneji.

[msoneji]

Anytime Gord.

Also note that in step 3 above the polarity of the 12v applied to the main connections will determine the direction of thrust. If it is +12v applied the piston will move one way. Reversing the polarity the piston will move in the opposite direction.

I am curious to know what he finds out.

[Helimech]

Thanks, good info. Thats what I thought. So with the clutch engaged when I apply power (12vdc) to the motor wires will it stop by itself when it reaches its out or in limit or do I haveto disconnect the 12vdc?

[msoneji]

I think there are limit switches inside the unit to stop it. However at first proceed with caution and disconnect the 12v before you hit the end. When you do test the limit switches, be alert and ready to disconnect. On the boat there also are physical limiters that stop the quadrant.

[msoneji]

Helimech,

Did you get to test your linear drive? What did you find? Regards.

[Helimech]

No I ran into fuel problems so that moved up the list above the autopilot. Hopfully this weekend i can test the drive. I'll post he results. Fingers crossed.

[Helimech]

Tested the drive today and it worked to spec. I tested it using the advice on this thread. Thanks to all. It did not seem to stop by itself when reaching the in and out limits. Not sure how it knows to stop. JC

[noelex 77]

The controller tells it to stop. When the rudder deflection reaches the programmed maximum the controller cuts power to the drive unit.
I am not sure if there are limit switches, but they would not be needed during ordinary operation (with the controller providing power to the drive)

[Helimech]

Thanks for the info. I had a feeling it was a controller/rudder position controlled stop.

[Helimech]

In digging thru my "stuff" I came across a picture of the breakdown of the actuator. If anyone wants a copy shoot me an email. Cheers, JC