Hello @ruankruger33, already seen Material thickness LR3 - #3 by vicious1
Do you need to cut full 75mm depth, or just the top portion? What kind of stock material do you need to cut, soft/hard? Have seen folks modify YZ plates to build taller LR3s, but they’re usually cutting foam or softer materials where the reduced rigidity of a taller LR3 isn’t an issue. You’ll need to find the right balance of height, feedrate, rigidity, material hardness and acceptable quality for your project(s).
Have seen people drop the cutting area to increase overall height capacity, or, achieve the same result by raising/packing height of the y-axis rails to be able to cut tall stock, while still maximizing LR3 rigidity by having cuts be as close to Min Z as possible. Building an LR3 with removable side rails, and/or height adjustable y-axis rails can help open up your options.
Hope that helps, cheers!