Raymarine Linear Drive - Repair or Replace?

[colemj]

Originally Posted by Viking Sailor

Don,

Sorry for taking so long to get back to you - it has been a busy day. I wasn't able to find the raymarine type 1 or 2 linear drive. I must have gotten rid of it somewhere along the way. I did find three other units. Unfortunately none seems likely to be usable by you.

Best of luck,

Paul

Paul,

There is probably a 12-step program for those of you with piles of this stuff tucked away!

Mark

[Capt.Don]

Originally Posted by Viking Sailor

Don,

Sorry for taking so long to get back to you - it has been a busy day. I wasn't able to find the raymarine type 1 or 2 linear drive. I must have gotten rid of it somewhere along the way. I did find three other units. Unfortunately none seems likely to be usable by you.

Best of luck,

Paul

Paul,
Thanks for looking. I'm off to the boat to replace the wiring - it's worth a try!
Don

[Capt.Don]

I'm leaning towards sending the unit to Raymarine for rebuild. I'm pretty certain the clutch is worn with excessive play causing it to bind. I'm also interested in the claim that the newer models have metal gears.

What I'm still confused about is the potential that this is electrical related. When I measure voltages at the control head and the linear drive, I read 10.7v on both. The technical manual indicates this should be 8-10v. I have cleaned all the connectors, tightened the female push-on/spade connectors and inspected the crimps (I agree, one of the 12v crimps does look suspect, it not crimped around insulation). I have not tested with another wire or replaced the connectors.

If this were caused by a loose connection, I should be able to wiggle the wires and the clutch would engage. Tapping the unit (as I've gotten in the habit of doing), is not wiggling the wires.

With no voltage drop and no apparent loose connection, what other electrical causes should I look for?

[NahanniV]

It's the clutch circuit you need to be looking at. Your photo shows the drive (motor) connection.

The suspect points are the connection at the control head (clutch) and the splice where the clutch wires of the drive unit are connected.

A high resistance connection could be showing correct voltage but not allowing current to flow.

You could check for current with a clamp on meter over one of the clutch wires, or by inserting a meter into the circuit.

If there is a high resistance connection in the circuit it will limit the amount of current that can flow in the circuit which limits the amount of force the clutch magnet can create; Tapping the drive could be supplying that missing force.

I have never heard of the clutch wearing out in one of these units.

Cheers,
John.

[Capt.Don]

John,
Thank you - as I recall, I measured the resistance on the coil and it also was within spec. I didn't test under load, though - I will retest. Good idea,
Don

[Capt.Don]

I wanted to update everyone - you might be right regarding the electrical connections. I made a jumper wire with small crimp-on connectors and remeasured voltages. In doing so, I discovered that one of the crimp-on connectors to the clutch and power were loose and actually came apart as I was goofing around with the wires.

I tried to route a new cable from the console to the autohelm - I don't have any way to route a new wire to the autohelm. Since this is an intermittent problem, I don't want to leave the NavPod open and wires in the cockpit (yet).

As the next step, I decided to redo all the existing electrical connections. I replace and crimped (good) on the control head, clutch and 12v power to the autohelm. My few tests today were positive. Over the next few weeks we'll see if this makes a difference. If not, I'll then revert back to the new/test wire that I prepared.

I don't have any expectations that this will work. At least now I've got good, solid, electrical connections at the clutch and power to the autohelm. This is just the next right step to eliminating causes before making the decision to have Raymarine rebuild the autohelm. At least I will have ruled out everything I/we can think of!

The saga continues (I'm tired of dealing with it, but I'm persistent!) - thanks again,
Don

[Cavalier]

Originally Posted by Capt.Don

I wanted to update everyone - you might be right regarding the electrical connections.....

...At least I will have ruled out everything I/we can think of!

A very noble effort in self-reliance. Somebody made a rash comment to me earlier in another thread when I mentioned that someone I once knew had paid a guy to pressure-wash their hull.. the response was to the tune of "well here WE practice DIY".. the oddness of the comment got me wondering - who doesn't practice DIY? at least in the sailing fraternity.. Anybody worth their salt would want to know their boat's systems inside out - as the chances are that the day it breaks down you'll be far,far from help.

After years of FATs, SITs and general equipment tests, everyone involved learned the mantra, "If you think it may be a problem, it will undoubtly prove you right: eliminate it before you continue!"

Keep up the good work! it's small forays into the nuts-and-bolts of system debugging like this that makes CF a treasure-trove of experiencial data for everyone else..

Thanks for the update.