Thanks, i have read of some innovative ideas re backlash removal.

Without sounding rude to anyone here, I have just had a reply from a very well respected heavy-duty expert in plasma cutting process and machinery via email, his examples of work are what i would like to see and are well known.

Due to my budget constraints, it is felt that I should be looking at V-Rails and rack and pinion, or, ground, flat plate and skates with rack and pinion for my build.

This makes a lot of sense and is in line with 90% of the commercial production built machines available - no point in re-inventing the wheel.

I will price up and sketch out a v-rail build.

There is another option for drive - open-ended toothed belt with an omega loop drive - this is simply a length of timing belt stretched tightly from front to back with the motor on the gantry and the belt wrapped in a loop over the sprocket. It is supposed to be a very good system as long as steel corded belt is used and it's pulled tight.

My existing build uses a belt but its looped which doubles the stretch possibility and its too small at only 10mm wide, also due to the poor design at the shafts, i cannot stretch it very tightly.

Its too easy to forget things like a budget at times :(

Need to get back on track now I think ;)