Have a CNC 3040 with a gantry that's too high. To reduce vibration, I moved the spindle all the way up in its collar. That results in a distance of 10.5cm from tip of spindle collet nut to the bed, or 9cm from tool tip. This is fine if I use a milling vise, but now I want to machine a large, 25 x 25 x 1 cm sheet of aluminum.



How can I raise the work up by 9cm?

Things I've considered:
1. stack wood boards underneath and bolt down - the problem is the height can't be precisely varied and I have trouble finding long enough bolts that can fit in the T-slots

2. lower spindle - I don't want to learn my lesson from https://www.cnczone.com/forums/chine...el-router.html again.

3. lower gantry height - I can lower at most by 4cm or else the clearance (yellow arrow) will be too low for the milling vise.

What I'd really like is an adjustable height table. I was thinking of a board with 4 screw feet or a scissor type lift. But 1 big problem I see is they can't resist lots load in the X & Y directions because the legs will have too much flex.