3-Axis CNC Mill Project

[JAZZCNC]

Ok I'll shoot first.!!

Please take what I'm about to say has help rather than pulling a design down.!!

That gantry is miles too narrow and it 99.9% will twist and rack even if you use 4 bearings in the arrangement you show. It will 100% rack if you use a single down the centre ballscrew using this arrangement.?
It does need 4 bearings but not like you have them drawn. They need to be in-line side by side creating a wide foot print.

The gantry cross bracing (Y axis) is no where near enough and it will flex with Y axis sides ways movement, 2 of those pieces would work much better.

If you are going to use this narrow profile then I would recommend you fasten wide plates at the bottom for the bearings to mount side by side.
Also some corner bracing wouldn't hurt.

Don't know where your inspiration for this machine comes from but it has a very Merchant dice feel to it and if so then let me tell you they are rubbish design which flex and move around like quivers jelly.!!