Up until this point, the build has been more generic.  This time I will add the plasma cutter rails.

The plasma cutter rails were designed to distribute the weight and forces of the Y axis out so that the when the machines moves the mass of the gantry at .3Gs, it will remain rigid and not wiggle or vibrate.

 

Mark the Rails

I placed the rails on the two Y carriages as shown here. They are centered with the same over hang on each side and flush with the ends of the riser.

Note that if you used a riser longer than 12", you will have to bring the rails in so that the outside edges of the rails are 12" apart.

I then marked the location of the two slots in the riser as shown here.  In my case the first mark ended up being 1.12" from the edge.

You need to mark both ends of the rail on both sides.

 

Drill the Holes

I drilled holes where I marked the slots and added some #10-32 machine screws and T-nuts to each hole.

 

Conclusion

The rails are slipped into the slots and made flush with the risers, as shown here.

I snug the screws.