I want to DIY.. some questions please!

[Tenson]

Okie-dokie!

Are you guys sure that gantry weight is not a problem? I was thinking I could use extruded aluminium profile, but it needs to be quite thick to be stiff, so I'd prefer to go with solid 20mm aluminium. Alternatively I could go with thin sheet and re-enforce it with carbon fibre struts.

[Jonathan]

Okie-dokie!

Are you guys sure that gantry weight is not a problem? I was thinking I could use extruded aluminium profile, but it needs to be quite thick to be stiff, so I'd prefer to go with solid 20mm aluminium. Alternatively I could go with thin sheet and re-enforce it with carbon fibre struts.

Yes we're sure. The mass of almost every CNC mill is significantly greater than a CNC router with good reason. It helps significantly to get a good finish and cut with a decent material removal rate. It is far more important to make the gantry strong than to make it fast and it wont make much difference anyway.

Extrusion is good for the gantry, but quite expensive. Consider steel box section or a combination of aluminium flat bar, extrusion or steel. You'll find plenty of examples of ways to do it with these if you search in the build log section.