Spindle speed display slowly increasing- Resolved with new VFD

[martyscncgarage]

Svin, please post a fresh system report.

[cncsnw]

Marty,

G96 is the code which selects constant surface speed. The G50 code sets a maximum RPM limit to be applied when running in CSS mode.

In G96 CSS mode, using imperial units (inches), the S value is surface feet per minute (SFM).

Regardless of whether you are running in G96 CSS mode, or G97 constant-RPM mode, the status window display in CNC12 will show RPM (not SFM).


A useful rule of thumb is that RPM is approximately equal to SFM at a diameter of about 4". Smaller than 4", RPM will be higher than SFM. Larger than 4", RPM will be lower than SFM.

For what it's worth, the diameter where RPM and SFM are equal is actually 12/pi, or about 3.82".

Svin,

When you run the program "abc.cnc", exactly as you posted it, what spindle RPM do you see in the turning cycle (lines 35-47)?

I would expect it to cut the first pass at about 800 RPM (200 SFM at a diameter slightly smaller than 1"). Each successive pass should run at a higher RPM. By the time X gets down to 0.45 or 0.375, you should be maxed out at 1500 RPM.

Earlier you described using "S800", and wondering why it always ran at 1500 RPM. 800 SFM at any diameter smaller than 2.03" will always run at your limit of 1500 RPM.

[martyscncgarage]

Thanks for chiming in Marc. Your experience is much appreciated!

Marty

[martyscncgarage]

SVin,
Plesae take a look at the lathe manual:
https://www.centroidcnc.com/centroid_di ... -v4.14.pdf
Specifically: 10.32 G96 & G97 - Constant Surface Speed Control & Cancel
There is an example there that shows you how to turn off G96 and use G97.

You have G96 turned on in both G code files. I had asked you to post the Intercon file as well. When you run Intercon, it generates is own file. The intercon files can be found in the icn_lth directory and end with .lth. This way we can change the file to run
Marty

[Chaz]

Having now seen a video of this fine machine, I need to ask, can you provide some details of what motors / ballscrews etc? What speed does the machine rapid at? Looks quick.

Lovely machine, congrats.

[kevincnc]

Thanks Chaz (if you mean my machine,) here's a CNCzone thread that I'll add those details to in the next few days. https://www.cnczone.com/forums/vertical ... oling.html
Kevin

[Chaz]

Thanks Chaz (if you mean my machine,) here's a CNCzone thread that I'll add those details to in the next few days. https://www.cnczone.com/forums/vertical ... oling.html
Kevin

Thanks

[frijoli]

What was the resolution? I got lost in this thread...

[martyscncgarage]

What was the resolution? I got lost in this thread...

TECO VFD, he replaced it