All good points @LuptonM. Opinion in the woodturning world seems divided (no surprise there!) about Tormek diamond stones. It seems agreed that grooving can result on the original Tormek stone, even with careful use of the jigs. However, the vast majority of sharpening at our space will not be turning tools, it is probably chisels, plane irons etc. So such a heavy investment in a diamond wheel is probably not justified for the minority of members who sharpen turning tools. Plus my understanding is that the diamond dressing accessory we have is not used on diamond wheels, so accidental damage and ongoing wear to the expensive diamond wheel could not be βfixedβ. But I could be wrong. It would definitely make sense in a private workshop dedicated to turning where really high degrees of sharpness are routinely essential.
There is also the question of which diamond stone to get - they come in different grits. Another level of complexity.
Overall, my feeling is to invest in a SG-250 original stone if it fits our Tormek (I will find out) for approx 140 GBP, because it will pay off in the long term as @lewisss says. So how do we action this? Does someone have the card?