Float precision for Ultra-Precision applications

Context:
I want to use Linuxcnc for a Ultra-Precision machine.
For that i need Linuxcnc to tell my drives (via Ethercat) the waypoints with high resolution.
I can get 0.5 nanometer resolution out of the Ethercat bus with the 32bit Integer format at the travels that i need. Which is sufficient.

Now as for my question:
From what i gather the path planner and everything works in single-precision floats.
Doing the math on that at 10mm and 500mm positions tells me the resolution between bits of the float number is not enough.
10mm/2^24=0.59nm
500mm/2^24 = 29.80nm

I dont want to waste that much precision in my control for no reason (plus having to convert to the scaled integer value).

Is there a way to change that to double precision floats (64bit) without having to rewrite the whole control?
Also feel free to tell me that my math is wrong^^

Leo
 

Wow so you're aiming for sub lithographic accuracy, you got any pictures of your machine ?
How you handling temperature, a dedicated controlled room ?
I guess this is a retro fit ?

That is below "Extreme Ultra Violet" with it's 13nm wave length.
What is the current TSMC node, 4nm ???

The feature size is still well above a nanometer, but the edge precision and positioning precision have been well below a nanometer for many years.

The numbers quoted for various generations, such as TSMC's 4 nm are pure fiction; merely a label. Real dimensions have not been used as generation names for more than 20 years.

(I spent my career in state-of-the-art lithography. Now I use LinuxCNC to build model steam engines.)

Gene

.5nm, isn't that just a bit smaller than 4 gold atoms ?

With the radius of a gold atom being about 0.135nm ?

GeneRF wrote:

The numbers quoted for various generations, such as TSMC's 4 nm are pure fiction; merely a label. Real dimensions have not been used as generation names for more than 20 years.

The first part of that statement is absolutely correct, but the second part i am not sure it's been 20 years.
4nm is feature size now, before it was transistor size. Last i checked when 7nm was in use, the transistor size was 14nm in total, or similar.
And personally, i am still not clear on how they get usable 4nm features with 13.5nm light source (molten tin hit by two lasers, all at 50000 times per second) etc, etc, but it sure as hell is astonishing!