Instrument (tacho) repair

[formerlyknownasprince]

I just hooked up a new cable to a mechanical tacho that I hadn't run before - and got a horrible noise - and stable readings. Its a 3" AC - runs to 4,000 (although max no load revs should be 2800)

I've pulled it apart and it has had water in it some time back. I've shaken about half a tablespoon of rust from the casing out - and the instrument itself looks OK. The needle will not come off with just finger pressure - and I am reluctant to pull everything apart.

The question is - should I be adding a lubricant? If so, what type - Inox? Graphite powder?

Ian

[Gary E]

I would submerge it in kerosene or any other very light oil. Soak it for a long time and then drain it before trying it again. If you can find an instrument repair company to service it, do so.

[ 10-18-2005, 08:52 AM: Message edited by: Gary E ]

[formerlyknownasprince]

I'm reluctant to go back to the instrument repair company in a hurry - I just picked up the two new tacho cables from them yesterday - for the second time. They made the inners 1" short the first time (with two good cables there as patterns too). I reckon they might be in cost recovery mood if I visit again in the near future :D

Ian

[imported_Craig]

YOu might try the avionics tech at the FBO on your local airport.