A new hope: Epoxy granite and steel.

[jarjar]

If your meaning to re-fixture and cut the other 2 sides then that's easily fixed, it's called an Angle plate bolted to the bed. Because that's all the Datron is providing with it's cut out, it's just an inverted angle plate built onto the end of the bed.

I can see how this would be problematic if you want to mill on the side of long pieces that won't fit under the gantry. With a fixed bed the cutout allows the work piece to extend below the bed. If OP wants to do a lot of those pieces then the moving gantry seems indeed the way to go.

About the sawn surface to bolt the spindle on, I think this is a big no-no. I'm not talking about precision watch making, just basic good practice for mating surfaces. If the contact area is bad, you will lose most of the stiffness and also distort the spindle housing, possibly damaging the bearings very quickly.

[JAZZCNC]

I can see how this would be problematic if you want to mill on the side of long pieces that won't fit under the gantry. With a fixed bed the cutout allows the work piece to extend below the bed. If OP wants to do a lot of those pieces then the moving gantry seems indeed the way to go.

Pro's and cons to both but IMO the cons for having the slightly longer length end machining the price is a too high price to pay in strength terms. There are other better ways. . . For instance.!

For high clearance requirements, I have a design that will work and provide high clearance under the gantry with minimal loss in strength. I've just built a small version with a cutting area of 500 x 500 x 350 that could easily have the clearance and strength increased if required without any impact to it's cutting ability.