andyp wrote: ↑27 Feb 2023 12:08
ive heard that if the coil goes in them they are pretty much dead and buried ?? so just thought i would check in with you guys to confirm this is the case, if not is there anyone who could repair it for me .
thanks in advance, Andy.
Yep Andy that's pretty much the case, my success rate of fixing coils is about 1 in 3, sometimes I get lucky and its a broken wire which whilst very fiddly is fixable but if its broken inside the coil its tough.
The coil itself could be removed, an new coil wound and fitted but its a former less coil glued onto a delicate armature which is part of the mechanism, totally uneconomic for me to do it commercially.
It seems that the symptom of the coil going faulty is that the tach under reads and this gets worse until it stops working.
Lively tachos are not always broken springs, or even mechanical issues, but often a circuit board fault. Totally dead ones; usually board fault.
I haven't seen one but I have heard that sometimes the plastic swells inside which stops it working.
I even had one that was supposedly fixed by a well known expert that had some connections that were not even soldered.
The open frame calibration potentiometer is often in need of a clean.
Circuit boards can be replaced, calibrated and new bezels fitted. This is tolerably interesting
Its difficult to get the bezels off and re-use them, so new bezel is needed.
whatever is done its a still an old instrument which isn't very accurate,
It would be better to update it to Arduino controller based stepper motor design
In any case a tacho on a Morini is largely an ornament.
Mark