Float precision for Ultra-Precision applications

Hi,

Precision of the entire machine and resolution of commands are two very very different things.

The setup and build of the machine itself are not the topic of this discussion. Please keep it that way.

PLEASE stay on topic.

Thank you

Sorry sir, didn't know you were the boss of what could and couldn't be discussed, I'll crawl back into my hole

Leo75Wolf wrote:

Is there a way to change that to double precision floats (64bit) without having to rewrite the whole control?
 

This is his original question, that we did not answer, so he is right.
While waiting for someone that can answer that, you might want to have a look at the source code, it is on github:
github.com/LinuxCNC/linuxcnc
Also, these might or might not help:
forum.linuxcnc.org/38-general-linuxcnc-q...ming-milling-machine
forum.linuxcnc.org/38-general-linuxcnc-q...cision-home-switches

Yeah but someone starts a topic mentioning half a nanometre it's going to raise some interest. It's getting around to the level of the CMM NIST has in the US.
Precision is interesting whether it's a machinist hitting tenths on a manual lathe, a grader operator nailing a sub roadbed to the millimetre, the construction of the bridge over the harbour in the capital of my state or the work of Brunel in the 1800s.

i believe all floating-point values in linuxcnc are doubles:

typedef double real_t __attribute__((aligned());
#define hal_float_t volatile real_t

should be enough to hold 32-bit integers without precision loss

I heard a whisper the devs wanted to implement hal pins as 64 bit values with the next release (when  2.10 replaces 2.9)