Nasa Clipper Duet Log problems

[Alcyone]

The nasa clipper duet speed log does not work on our boat? It seems to turn well by hand, and the speed shows, but when sailing, it does not register. We thought at first that we'd got some antifoul on it by accident, but it turns very very easily now.

Any thoughts/things to check?

 

[sarabande]

when in the tube and extended, is the cable "nipped" or somehow shorted ?

is there an obstruction ahead of the impeller when immersed and moving (e.g. weed ?)

errr, is the impeller properly aligned fore and aft when immersed ? It's not impossible for the tube to have turned off centre.

 

[ms1]

mine does this. I can usually get it working with some welly in reverse. It seems to be very sensitive to weed and on the Thames there is a particular lttle worm that likes to 'sleep' in there. Also reliability was affected when I wacked into a great lump of hawser in the Thames at 20 knots so I think the spinner received a whack and may have bent one of the little pins on which the thing turns. Plan to replace the spinner next time out of water.
IF you can twiddle it by hand you (well another pair of eyes probably) should see a reading on display .. if not then there may be another fault.
Check for any corrosion where cable plugs into the back of the display unit.

Also there is a hard RESET you can do if all else fails (not in handbook) give then a call and NASA will tell you how to do this (I forget to write it down when they told me)

 

[hubert]

I had a similar problem with my nasa log last season. I rang them and they advised that I take out the paddlewheel, ( simply push out the bronze pin with the end of a biro.) polish any growths off the pin with a pan scrubber, paint the wheel with antifouling and, when dry, reassemble. I did this and have had no further trouble.

 

[Trundlebug]

I too had a similar problem which had me baffled for a while.

The paddle span freely but when inserted there was no speed showing.

It would seem the paddle is quite sensitive to direction - it only has to be a few degrees out for it not to rotate.

The solution for us was to get the boat going, then with SWMBO at the helm, you go down to the transducer and slightly loosen the clamp nut. Slowly rotate the transducer clockwise then anticlockwise until you can hear / feel the paddle wheel turning. Get SWMBO to call out the registered speed, keep turning back and forth until you get the highest speed reading then retighten the clamp nut.

Good luck

 

[Drascomber]

Mine is ludicrously intermittant which I put down to high sensitivity to weed but have no way of telling short of hoiking it out far too often to contemplate.

Can you put some kind of cage over it?

 

[Alcyone]

Just got back from work. Thanks for the replies, plenty to try out there.

THanks,

Alcyone