Speed and Feedrate

[kjm30]

This is my first post for this forum. Recently I had some problems learning on how to calculate the forumulas for RPM and SFM also feedrate such as IPM and IPR.

The Spindle Speed is also RPM correct? On the Kennametal catalog they provide the SFM starting speed and the starting feedrate.

For example the 1 1/4 Indexable Drill has SFM of 760 while 0.004 IPR?
The formulas states that to get RPM (SFM x 12 divided by 1 1/4 x 3.14) = the RPM would be 2322 which what it will show on the screen on how fast the Spindle would be?

Then when to program the catalog offers the IPR which would be 0.004 then on the screen while machining it will show 9.288 (RPM x 0.004)

I have been confused on thinking the SFM is actually the spindle speed?
Is it safe to keep the spindle on 100 percent while keeping the feedrate perhaps 50% just to be cautious?

Thanks

[zman300]

Yes spindle speed is RPM.
Another formula for RPM is (SFM x 3.82 divided by 1 1/4).
Your RPM and feed rate are correct.

You can start at 50% feed and inch it up to 100%.
Remember to little feed can also cause a tool to wear faster.
It will be rubbing and not cutting, generating more heat.

[kjm30]

The controller is Fanuc OiM. When the feedrate override switch is at 100%, the rapid movement is way too fast for me however I need to leave it in 100% for the programmed cutting speed. The only way to think of it is to convert the feedrate to higher rate when switching the override switch to 50% then the feedrate would have to be programmed 50% more? But this would be way too confusing for me.

[dcoupar]

What make and model of machine is this? Doesn't it have both a feedrate override and a rapid override?

[fanuc-support.c]

The parameter to reduce the rapid travel speed is 1420, it's a value in mm/min.

Whatthe problem with the rapids being "rapid"? Thats what there designed for, i imagine this parameter would have been set by the MTB, so it's save as housing, let it fly.

[User1983]

Originally Posted by fanuc-support.c The parameter to reduce the rapid travel speed is 1420, it's a value in mm/min. Whatthe problem with the rapids being "rapid"? Thats what there designed for, i imagine this parameter would have been set by the MTB, so it's save as housing, let it fly.

So I have been trying to optimize a milling process on a Komo VMC with a Fanuc series O-M control. The Feed rates seem to be higher then the machine rapid and i cannot find a parameter list in the manuals that i don't have to tell me where the rapid rate may have been changed. Do you know where i could look to find this information?

[zman300]

Oh you're talking about rapids
I thought you were talking about feed rate.

Of my 3 vmc's one has rapid override the other two don't. Not sure about the parameter to change.

Instead of a G0 rapid move you could do a G01 X? Y? F100.0 to slow the move down.
I use that on turning machines depending on the move I'm making.

[kjm30]

The machine is Fadal 4020 Fanuc OiM

I actually needed to know the feedrate speed. But to achieve the correct feedrate the switch has to be on 100% but the switch is also for rapid movement. Two in one switch.

My company does not make many products in a certain time mainly more for precision and quick production.

On other note, I tried the correct 760 SFM speed for Kennametal DFT Indexable drill which I programmed it at around 2326 RPM with 11.63 Feedrate (0.005 IPR) but still it looked too fast and got too hot. The material is Grey Cast Iron. So I decided to go back to 760 RPM (when I got confused that SFM is RPM) with 3.80 Feedrate?

[dcoupar]

Originally Posted by kjm30 The controller is Fanuc OiM. When the feedrate override switch is at 100%, the rapid movement is way too fast for me however I need to leave it in 100% for the programmed cutting speed. The only way to think of it is to convert the feedrate to higher rate when switching the override switch to 50% then the feedrate would have to be programmed 50% more? But this would be way too confusing for me.

Have you tried running with the RAPID O'RIDE on (lamp illuminated)? It's supposed to reduce rapids during program execution by 50%.