Quote:
Originally Posted by ajgriff
Looking at your photos again it looks like you've already withdrawn the shaft so I hope I haven't confused matters. The central insulating sleeve seems to be still in place and this is the component which is secured by circlips at both ends on the smaller version. Hope the diagram helps a bit anyway. I suspect that you will end up with a very worthwhile working Variac. 
Alan |
Not at all. Yes I had withdrawn the shaft and knob, which was the only way to remove it. The knob is still held fast on the shaft as I can't budge the screws. It was I who probably confused things by referring to the insulating sleeve as 'the shaft'. I appreciate your input and did check just to make sure that there were no circlips or anything other that might be holding it together. I didn't find anything and the guy in the video does not appear to remove anything further so I proceeded with another strategy.
This was to use a large socket to push the insulating sleeve out of the base. A spark plug socket seemed just the right size and allowed me to use a little more force. Sure enough after a handful of taps the shaft started to move. I proceeded steadily and several taps later it popped out and the two halves separated. Photos attached. In excellent working condition? Tested before dispatch? It doesn't look like the wiper has run along those tracks in a very long time! I am not at all surprised that I was getting a high resistance reading to the wiper connection. I would definitely not have applied power to that for any testing until it had been thoroguhly cleaned!.
Well now I have got this far, the next step will be to remove the coil from the base and see whether the base can be straightened. For now, though, I will get a brush and clear out the debris!