Perhaps I'd better kurb my enthusiasm for cutting tool steel then Jazz, to be honest I'd be happy cutting ally.

Right, so the 2 linear guides either side wouldn't be of any real benefit. That's good, that'll save me a few quid and hopefully make the overall design easier.

What about the linear guide width, 25mm OK? Bearing distance, there's about 105mm between the ends at the moment. Would you recommend at least doubling that?

Thanks for your input.