"Origami" CNC Plasma Build - folding 1200 x 600mm cut area

Bit of a question for the likes of tommy, rod and anyone else who has experience with the shaped linear rail systems.  I had been planing on a single 15mm rail on the X axis.  My logic being that the forces on the Z carriage are not that high in the scheme of things.  Nothing like would be happening for a router.  However looking at Rod's X axis build I can see dual rails.  Am I heading into an area of frustation with "waggle" on the Z if I only have a single rail on X?  Should I be biting the cost bullet and have two?   I had been hoping to avoid the weight as well as the cost.
Is a single rail on the with some bearings as runner wheels to provide some extra support an option? 

Open to advice and education on this.

Thanks - James.
 

I think if I did mine again, I would just use one rail and a helical rack and pinion which would "key in" to help with axial loads.. I'd probably use a larger rail, probably HGR25 becasue its easier to buy but from memory HGR15 would meet the loads. I used 80x40x4mm aluminium RHS for the rail.

Oh and if you go to my website, there is an email in the footer. I did round up that assembly for you this morning. Send me an email so I can share it with you from Google Drive.

Oops. go here www.vmn.com.au/
 

Email sent.

That RHS section looks exactly like what I had been planning on. 

 A little progress this weekend.  Got the Y axis linear rails cut in between the rain.  Also printed these aignment jogs that I was shown bby a friend that he used on his hypercude 3d printer.  So after some looong print time as these are significantly bigger I have two.  And they work a treat. Instant alignment to within sub 0.06mm. 
Mounted rail


An alignment bracket
 

Checking how accurate it is to top of rail
 

Setting middle of rail to zero as reference point
 

Right then Left tavel check.   Pretty good at 0.02mm from zero.  In sweeping across the length and bearing in mind this is hot rolled steel with primer on it there is 0.05 to 0.06 of variation.  I would say that is pretty dang good given how this is all being put together.
 
 

I think a pretty good start to getting these rails lined up and ultimately in place. 

Cheers - James.

Getting things mounted up.
 

Good Work James,

Looks like it's really coming along now 

Cant wait to see the gantry on and how you go with the z axis

Cheers

Here are some draft images of a Z axis design.  I am trying to make as low profile as I can manage with components that are either readily available or not too challenging to create on a lathe or mill.

Cheers.