Bit more today...

The bare frame - extremely rigid, surprised me!
Click image for larger version.  Name: IMG_1241.jpg  Views: 411  Size: 1.33 MB  ID: 17744

Inside of the front plate (maybe the back, not sure yet) idler bearings to shift the belt path...
Click image for larger version.  Name: IMG_1242.jpg  Views: 381  Size: 727.6 KB  ID: 17745

The Y axis screws temporarily fitted...
Click image for larger version.  Name: IMG_1243.jpg  Views: 392  Size: 1.14 MB  ID: 17746

The gantry being built up...
Click image for larger version.  Name: IMG_1244.jpg  Views: 433  Size: 1.12 MB  ID: 17747

The Z axis in place...
Click image for larger version.  Name: IMG_1245.jpg  Views: 413  Size: 876.9 KB  ID: 17748

Z axis lifter screw and motor fitted...
Click image for larger version.  Name: IMG_1246.jpg  Views: 457  Size: 1.05 MB  ID: 17749

So far, my CAD efforts have been 100% perfect, every single part drawn has fitted just where it should be Torsionally, the gantry is very stiff - pushing on one side brings an immediate response from the other which is good, the Z axis looks like it will be just as tight.

Now i need to fabricate an idea for a method of joining the Y axis nuts to the gantry cross-beam.