Aluminium profile CNC

[JAZZCNC]

I would like to have your opinion guys. I'm want to be sure to understand this: What's the difference between having high side plate like my first design and the newest one? In my point of view, the sideways movement are less important if you have short side plate. Will it be stiffer? And will vibration be a problem ?

It's late here in UK and I can't be messing around looking back thru 60+ posts to see your design so I'll answer this using my experience of building all types.

Sitting The gantry directly on the bearings using high sides does give much stiffer machine. This leads to less vibration at the tool giving better surface finishes and less tool wear.
However, this is only really needed if cutting mostly harder material like Aluminium/Brass or very hardwoods. If just cutting a general mixture of all materials but mostly woods then gantry with side plates isn't a problem provided the gantry is strong and the plates of suitable thickness and securely braced to bearings.
There are advantages to the machine using gantry sides if mostly used for wood or sheet materials because of easier material loading and access etc.

I have built machines which use both types and in real-world use, both will cut aluminum fine. However, the High side machines can be run little more aggressive in harder materials due to being that little bit stiffer.
You have to decide whats more important to you, higher Stiffness or better accessibility and little easier to build.