Neale, thanks for your honest opinion and advice. I had a look at the JGRP designs and did learn something from them. I'm not going to use much mdf only for the bed as I guess you mdf can swell as much as 4% even if sealed, left unsealed in damp conditions then 20% is not uncommon before it ruptures.

JAZZCNC, I don't intend spending much as I ain't got much to spent on the build.

Ger21, thanks for your input I would be interested to see some pics of your machine if you have any to post.

Silyavski, thanks for your input and advice. I have not seen the V casing on ebay can you post a link please. Also please post the pics of your Z axis please, yes I was thinking of using belt drives for the X and Y axis with liner round supported rails or profiled + blocks on the Z axis. NOTED your comments of V bearings LOL
Having costed up some stainless steel angle today as an alternative to round tube which I've several 4ft lengths I might as well buy supported rails as it would be cheaper.

Beone, thanks for your input. I know what you mean about shielded bearing and dust, as I was looking at a vertical panel saw with problems today and part of the problem was the bearings sticking apart from the resin build up on the rails, no wonder is was jumping out of the track. Can you post some pics of your machine please.

EddyCurrent, thanks for your input, yes I'll do some test and post them to the thread once I've got a machine built.

Mike :)