Thanks Michael,
It is indeed the thread I could not find! I have followed the instructions on that thread and despite some derogatory comments from some, I am pleased with the results. I have used silicon carbide 100 grit glued to a piece of plate glass. The only other mod was to affix rubber tyres to the slippery offset wheels. If the drill bit is very blunt, I can see that it would take a lot of effort to sharpen it.
I always re sharpen my drills as soon as they start to show signs of wear. If one does this, then the Eclipse No 39 gives a very acceptable and quick solution. It is in fact surprisingly good, far better than I expected.
Andrew.