Lathe spindle rpm "ACT" Vs "S"

[dmbgo]

When I use CSS with my lathe while turning, I see 2 spindle speeds. One spindle speed is labelled "ACT" and the other spindle speed is labelled "S".
I am wondering what these 2 things mean?

[tblough]

Act us the measured spindle speed according to the spindle encoder. "S" is the commanded spindle speed from the G-code.

[dmbgo]

Thanks Tom, so when my Act and S rpm are very far apart, there's something wrong?
The reason I'm asking, is because they are vastly different. ACT=41 S=381 right now. I think it might be because I have chosen a low gear on the lathe to turn a 75mm piece of steel.

[suntravel]

You have to setup the gear reduction rates in the Wizard or Parameter 67-67 and tell the CNC with M41-M43 which gear is used.

For manual operating use Spin High / Medium / Low on the VCP.

Uwe

[dmbgo]

Thanks Uwe, I've just finished turning something, so I'll give that a go.

[dmbgo]

Hmm, I just had a look in the wizard and I could see High, Medium and low speeds and their assosciated ratios, but my lathe has 9 different speeds. Should I just pick 3 x speeds and use only those with CNC12?

[suntravel]

Hmm, I just had a look in the wizard and I could see High, Medium and low speeds and their assosciated ratios, but my lathe has 9 different speeds. Should I just pick 3 x speeds and use only those with CNC12?

Yes, with a VFD on the spindle motor you do not need all gears.

I have made my own M41-43 macros to make sure the right gear is selected

https://centroidcncforum.com/viewtopic. ... M41#p62945

Uwe

[dmbgo]

Do you mind if I copy your macros Uwe?

[suntravel]

Feel free to use them

Uwe

[dmbgo]

Thank you. I have just downloaded them, I'll give them a go. While we are talking, do you remeber the "easy chamfer" we were discussing a while ago? I would love a button on my vcp....