Centroid Community CNC Support Forum

It would be nice to have a Spindle Speed Variation function (for Mill) that could vary the rpm over a given range and given timeperiod.

This would help avoid harmonics/chatter when workholding or stickout is not optimal.

See haas M138 function.

thanks for the suggestion, i've seen that haas feature.. does it really work?

Yes, it really works. I'm currently doing this with my MPG by hand.
It would be very nice to have this function for turning and milling.

Give it a try!!!!
Take a bar of long material that would definitely squiggle and chip it down...
Then they make the MPG faster and slower about 10%.
The whizzing will disappear.


Stephan

This also is very good for turning long thin parts.

Uwe

Works well for chipbreaking. What you can also do is add an accelerometer to the tool/spindle, measure the resonance peak, and vary and or change the rpm to be out of that range.

I ask the question whether Uwe can do that?
put something like that together

Do we need either a macro or an intervention in the system variables?
If it were to change the variables it would be time-consuming.
Then it would be a job for Centroid.
You can read a sample of what something like this can look like in every Haas manual...
It just says that you can turn it on and off and then there is a parameter in % or how much rpm it should regulate up and down.
This should actually be easy for Centroid team.

It would also be possible to put this function in a macro
then you can start and stop with an m command.
that would be better.

I think it is possible to build a SSV function in the PLC...

Uwe

Of course its possible
The question is whether you would like to make something like that?
Because if you feel like doing something like that then it works and it will be finished this year


I have something else for you......Have you changed the angle when cutting the G76 thread yet?
Do that and change it to 30 degrees for metric threads.
Up to M16 I can cut without an angle but then you realize that it is a hobby machine.
Try it in steel at 30 degrees, which halves the cutting forces and gives a nice surface.

This also work for milling fyi
Haas's implementation is pretty simple. but it works

Stephan wrote: ↑Sat May 18, 2024 9:32 am Of course its possible
The question is whether you would like to make something like that?
Because if you feel like doing something like that then it works and it will be finished this year


I have something else for you......Have you changed the angle when cutting the G76 thread yet?
Do that and change it to 30 degrees for metric threads.
Up to M16 I can cut without an angle but then you realize that it is a hobby machine.
Try it in steel at 30 degrees, which halves the cutting forces and gives a nice surface.

Better to use 59-60 degree in Centroid CNC for G76 and metric threads

For my lathe with lots of lash in the spindle gearbox SSV is not a good option, so my motivation to spend lots of hours on this is quite low, since I am very slow in PLC programming

Uwe