Vintage Capilano Rudder Sensor

[docvchulek]

I have a 71 Monk with a Capilano rudder sensor and indicators. The needle on the sensor barely moves when hard over as you see in the photo. It is the same in either direction. I assume I can make an adjustment in the sensor but I am not able to find anything online. There is a screw on the top of the sensor but this looks like a trim adjustment. The indicator has 0-500 microamps listed on the upper left corner of the picture.

Does anyone have experience with this system? Is it a voltage or resistant type sensor or do I make the change on the indicator?

Thanks for your help.

 

[Xsbank]

I don't know that system but it's solidly built and old school so I would try and get inside it to hose it down with contact cleaner (after having checked all the connections first). I suspect that the flat-head screw holds the top on, the hex-head is an adjuster. It looks like a rheostat-type but that adjuster might be for tuning the sweep arm.

I'm pretty sure it's not the gauge, that sort of quality, if not working, would be obviously damaged by corrosion or gummy lube.

That tuning-fork looking thing on the gauge is the needle adjuster.

Send it to me and I'll tear into it! Interesting and great boat-stuff.

 

[docvchulek]

I don't know that system but it's solidly built and old school so I would try and get inside it to hose it down with contact cleaner (after having checked all the connections first). I suspect that the flat-head screw holds the top on, the hex-head is an adjuster. It looks like a rheostat-type but that adjuster might be for tuning the sweep arm.

I'm pretty sure it's not the gauge, that sort of quality, if not working, would be obviously damaged by corrosion or gummy lube.

That tuning-fork looking thing on the gauge is the needle adjuster.

Send it to me and I'll tear into it! Interesting and great boat-stuff.

Xsbank, thanks for the encouragement (as always), I am always leary of opening stuff up and then a spring pops out. Nevertheless, I think that is what I will have to do. I will send photo updates when I get back to it.

Yes, the fork lines up with a modified screw on the cover to fine tune the rudder indicator.

 

[Lepke]

It's usually the sender that's bad. I think the sender is like a small rheostat. It has a coil and as the rudder turns, a finger rubs the coils. Newer ones use some kind of influence. I'm not a tech. The actual part can be found at an electronics supply. Maybe ebay. Usually there's a number and some company id on the part.

 

[EngNate]

I haven't seen one of these before, but I have a hunch it has the same internals as the old Wagner and Teleflex and still current Com Nav units, including a 1000-ohm precision potentiometer in the sensor which I think can still be obtained from Com Nav. The pot's do fail when water gets to them. There may be a 'span' adjustment, it would be on the back of the meter, but I doubt it's the issue. Be sure you have proper power supplied at the meter. Go ahead and open the sensor, nothing will fly out. You may well see the smoking gun inside. Post a good pic of the pot, I should be able to tell you if it is the Com Nav one.

 

[docvchulek]

Here is a quick update. There was no cap, the hex nut is too tight to turn, probably will need some heat. I turned the flat head screw and it seems to be an adjustment as the RAT arm moved a bit. I removed the four screws holding it onto the wood and the bottom is crimped on. Next I will check the electrical leads with a tester. I moved the RAT arm back and forth a bunch hoping to clean off the rheostat but it did not make any improvements.