Autopilot Drive Selection

[colemj]

Originally Posted by Neptune's Gear

The main difference between it and the production versions, is that the BODY of the ram is fixed to the quadrant, not the arm. This means the body slides up and down the arm, rather than the arm moving in and out. One end of the arm is fixed to a bulkhead.

In practice, that is just semantics with a hydraulic ram. The production versions could also be mounted this way. For most installations, it is just easier to mount the other way.

Did you have to modify your quadrant to mount the ram body? Most installations use an independent tiller arm because most quadrants don't have good strong mounting options.

Yeti, I wouldn't worry about maintenance. These are closed systems, so you shouldn't have to top off fluid, or even change it. After 14yrs of our hydraulic ram's life, it needed a new seal.

Mark

[Pirate999]

Originally Posted by DeepFrz

Did you do any research on the internet about these units?

Higly recommend you do this. You'll find much information about failures of the simrads but very little on the raymarine and garmins.

Also, find out who actually makes the unit. As an example, Garmin makes the head and course computer but not the actual drive unit. They use 2 different manufacturers. IF you find out the manufacture of the drive I'd suggest contactin them about failure rates (MTBF), etc. I'm finding out that most failures in a system are drive related and not compass, head or computer related.

[colemj]

I searched and found some complaints about the Jeffa compact drive unit manufactured before ~2008. It seems like they had a bad seal on them that allowed corrosion, and they later changed the design of this seal. I found no complaints about them after this period. Also, all of the complaints seemed to be from owners of a particular boat model, where this drive was mounted in a wet area.

The Simrad is a rebranded Jefa compact drive. Garmin uses the Jefa linear drive on their smaller systems. Raymarine uses their own linear drive, but it is probably made by someone else and OEM'ed solely to Raymarine.

I have found most autopilot failures to involve the mounting system - on both the quadrant and fixed ends. Second most involving electrical supply. These could be considered drive-related, but the drive itself is usually not the problem. Like you, I find the electronic components pretty much trouble free barring catastrophic events like lightning strikes.

Mark

[Cliche]

I know it isn't one of the ones you are currently looking at, but worth the browse at least. Check out CPT Autopilot. Cost effective, easily mounted, quiet, and rugged. It's only real downside so far is that it is a standalone unit. Doesn't interface with anything just holds a heading.


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