Thank you JazzCNC,

That really cleared things up, expecially with the pictures.

With regards to the profile rails i had a look on ebay and they seemed to get quite $$ when i was looking at the longer lengths, but ive found them on aliexpress and they seem alot better priced and with more options, is this where you get yours from?

i had a look for the Z axis for example and found these rails
http://www.aliexpress.com/item/EGR15...828633643.html
and these blocks
http://www.aliexpress.com/item/1PC-H...044267870.html

Are these the right kind of thing? Only reason im asking is there seems to be different versions ie HGR MGN.

Sorry about all the questions.

Thanks again

Trev