Quote Originally Posted by hanermo2 View Post
Fwiw..
Haas machines are all solid bolted to the floor via adjustable anchors.
Part of the included-in-cost installation is very precisely levelling the machine.
To within about 0.02 mm.

Everything flexes, and the modern machine beds or frames wont be straight unless they are mounted perfectly level. +/-.
And if they cut a part of max size, it wont be perfectly flat, straight, and level to within 0.02 mm guaranteed (which is not so accurate in fact).

A VM6 will cut a huge mold to within 0.02 mm, volumetric, mostly much better than 0.01 mm, no problem.
Linear scales, a 13.000€ option, wont make it any more accurate, but it will insure the client gets what they paid for.

My client was extremely happy, with the VM6 with scales, replacing a machine, chiron, that had been 4x more expensive in it´s time.
Making very very intricate 3d molds in steel, maybe 3000 kg each, that really needed to be accurate.

The molds cost about 250.000 € each, and need to have errors of no less than 0.04 mm, otherwise it shows in the final product.
A truck bumper might need upto 8 pieces with 8 molds.

I´m on the ethical edge with disclosure.
The general parameters above are known to anyone making molds industrially.
It´s not right to go into any more details -- most of which I don´t even know.

0.02 mm volumetrically is hard to do.
On a single axis, a short distance, it is trivial.
Anyone local cutting keys for locks does that.

The difference is about ...
2x-3x the distance, 3x, so 3x pwr 3 = 27,
times 3 axes, 81 times less rigid/accurate.
...which confirms my conclusions in this thread about permanently keeping a CNC on castors. Bolting may be necessary for that machine, and I am sure it is, but even for hobby machines, a solid base is necessary, even if not bolted, and that can not be provided if the machine is resting on rubber, silicon, or plastic wheels. They simply can never provide enough stability for the use case.