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

If your going to have a THCAD card and a floating head with a touch off switch then bed level is not important. What is important is the X and Y axes are perpendicular to each other.

I put a slight curve in the sacrificial slats so they would not be fully under a straight cut and that also made the slats very rigid so small plates don't wiggle as the machine moves.

gnipsel.com/images/plasma/
gnipsel.com/shop/plasma/plasma.xhtml

JT

JT - re the axis being perpendicular to each other I guess other than being careful on construction that next part is getting the racking on the X under control.  Dual motors and independent homing with adjustable home reference points being key to that exercise?

After getting distracted by a new SLA 3D printer (never had an SLA one before) I got back to the getting the top frame proper mounted.  Success after a little drama trying to drill holes with a hand power drill.  Ended up having break out the TIG to fix a bung hole that was off position by just enough to be a problem.  Then big mill to the rescue!

 

After that it was easy and while it was on there power tapped the holes.  We now have finished hinges and top mounted!
 

Now there really is no more excuses time to tackle the Y axies linear rails and making the sides to support the X axis.  That will allow some motion testing as well.  I have the basics of the 7i76e all working on a test bed along with the drivers and motors.  I also have all the drive belts and reduction gears for the motors.

Cheers - J.

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. 

15mm rail should be more than enough, the only unknown is how many times would it survive ramming it into the slats at full speed !
I used a single 25mm HiWin rail and a single carriage on many machines, they are still in perfect working order despite the owners not cleaning them ever!
But if a spec of plasma dust gets inside it will lock the carriage, so a bit of care should be taken when installing the carriage to the rail.
As a general rule, mount the rail at the bottom of the gantry, use screws in all the holes on the rail, have the gantry at least 15 to 20CM above slats, make the Z axis have at least 15cm of movement as it comes handy for cutting designs on square tubes.
Plenty of info here:
forum.linuxcnc.org/plasma-laser/35349-cn...fo-and-guide?start=0
forum.linuxcnc.org/plasma-laser/38974-di...rything-in-one-place