[nicubila]

@mactec54 curently the spindle works at program S speed irrelevant if the feed rate is full or decreased. I am looking for a solution to obtain a reduction of the spindle rpm when the feedrate is lower due to corners. Either controller or program, it does not matter how i obtain this. But as @dazp1976 says, the S will not change on the fly, and the axes will stop to adjust for the S, which makes the situation worst.
Ideally what I need is a way to have lets say
10m/min feed rate and S 20.000rpm wehen in straight line
and
S 8000rpm when feed rate goes down to 4m/min as it goes through a curve and axes need to slow down.
And if the corner and precision requirement are tight and feed rate must go lower, the S should not go below 5000rpm.

I am a bit surprise to find such little info about this option in online sourced. It goes along the concept of constant removal rate, and should be easily achieveble as an interpolation of spindle with the other axes.
As I said when I cut plastic I see that higher rpm makes nice cuts on straight line cut burrs in corners, lower rpm nice corners but spindle is struggling in straight line.

[dazp1976]

@mactec54 curently the spindle works at program S speed irrelevant if the feed rate is full or decreased. I am looking for a solution to obtain a reduction of the spindle rpm when the feedrate is lower due to corners. Either controller or program, it does not matter how i obtain this. But as @dazp1976 says, the S will not change on the fly, and the axes will stop to adjust for the S, which makes the situation worst.
Ideally what I need is a way to have lets say
10m/min feed rate and S 20.000rpm wehen in straight line
and
S 8000rpm when feed rate goes down to 4m/min as it goes through a curve and axes need to slow down.
And if the corner and precision requirement are tight and feed rate must go lower, the S should not go below 5000rpm.

I am a bit surprise to find such little info about this option in online sourced. It goes along the concept of constant removal rate, and should be easily achieveble as an interpolation of spindle with the other axes.
As I said when I cut plastic I see that higher rpm makes nice cuts on straight line cut burrs in corners, lower rpm nice corners but spindle is struggling in straight line.

Can you just cut it 'normal' or faster but this time leaving say 0.2mm+ on the stock (roughing).
Then run a 'slower' pass all around it at full depth right at the end to remove the left on material. (finishing).
That will prob work.

[nicubila]

Can you just cut it 'normal' or faster but this time leaving say 0.2mm+ on the stock (roughing).
Then run a 'slower' pass all around it at full depth right at the end to remove the left on material. (finishing).
That will prob work.

Both sides of the cut are active parts, so i need then both. I use the suggested technique in other cuts, but here is not feasible

[mactec54]

@mactec54 curently the spindle works at program S speed irrelevant if the feed rate is full or decreased. I am looking for a solution to obtain a reduction of the spindle rpm when the feedrate is lower due to corners. Either controller or program, it does not matter how i obtain this. But as @dazp1976 says, the S will not change on the fly, and the axes will stop to adjust for the S, which makes the situation worst.
Ideally what I need is a way to have lets say
10m/min feed rate and S 20.000rpm wehen in straight line
and
S 8000rpm when feed rate goes down to 4m/min as it goes through a curve and axes need to slow down.
And if the corner and precision requirement are tight and feed rate must go lower, the S should not go below 5000rpm.

I am a bit surprise to find such little info about this option in online sourced. It goes along the concept of constant removal rate, and should be easily achieveble as an interpolation of spindle with the other axes.
As I said when I cut plastic I see that higher rpm makes nice cuts on straight line cut burrs in corners, lower rpm nice corners but spindle is struggling in straight line.

What dazp1976 has said is incorrect, the machine will not stop to change speeds or feeds you can not use the ( S ) by it's self it has to be M3S--------

You have not said what control you are using as some controls already have this, they will slow down at a corner automatically, but don't normally change the spindle speed

You can do all of this in your program at the end of the straight cut M3S8000 and then at the next move add the Feed move, this will change on the fly so at your G2 or G3 line just add the Feed Rate F-----

You may need to have a Braking Resistor if you don't have one, for a rapid slow down of your spindle, or the VFD Drive may shut down

The Spindle speed change needs to be on it's own line M3S8000 and the Feed on the line of the move

[dazp1976]

What dazp1976 has said is incorrect, the machine will not stop to change speeds or feeds you can not use the ( S ) by it's self it has to be M3S--------
You have not said what control you are using as some controls already have this, they will slow down at a corner automatically, but don't normally change the spindle speed
You can do all of this in your program at the end of the straight cut M3S8000 and then at the next move add the Feed move, this will change on the fly so at your G2 or G3 line just add the Feed Rate F-----
You may need to have a Braking Resistor if you don't have one, for a rapid slow down of your spindle, or the VFD Drive may shut down
The Spindle speed change needs to be on it's own line M3S8000 and the Feed on the line of the move

Learn something new everyday.
That might be useful when milling a block of ally.
Sometims tend to go too big a woc when rounding off an edge.
The slow down could be benificial for the first few passes.

[nicubila]

I see now what you mean, and frankly i did not try this option. But I should try it then with an M3 and proper S.

I use a Delta NC300 controller, but could not find yet a parameter that would do this. That is why i was thinking of options to do this in CAM toolpath. doing this by hand is out of the question, there are thousands of corners in each model I make. Any change would require manual change again.

My best bet is for now is a very sharp tool with lots of clearance (so far Datron are very good), allow for the highest tolerance i can afford in the corners (so feed rate remains high), compromise on the highest feed rate, and find a sweet spot between the straight line feed rate and corner feed rate.

[mactec54]

I see now what you mean, and frankly i did not try this option. But I should try it then with an M3 and proper S.

I use a Delta NC300 controller, but could not find yet a parameter that would do this. That is why i was thinking of options to do this in CAM toolpath. doing this by hand is out of the question, there are thousands of corners in each model I make. Any change would require manual change again.

My best bet is for now is a very sharp tool with lots of clearance (so far Datron are very good), allow for the highest tolerance i can afford in the corners (so feed rate remains high), compromise on the highest feed rate, and find a sweet spot between the straight line feed rate and corner feed rate.

This software can change the feed rate on the fly while it is cutting the part running VoluMill

https://www.3dsystems.com/software/gibbscam/volumill

[nicubila]

This software can change the feed rate on the fly while it is cutting the part running VoluMill

https://www.3dsystems.com/software/gibbscam/volumill

That sounds good, it is worth trying, thank you