Need Help!- Reduce spindle rpm

[mukesh_21]

Hi,

I am new to CNCZone. I have toyoda FA450 HMC having Fanuc 15M controller. It has spindle speed range of 100-12000 rpm. I have taping operation in one of my job which needs 50 rpm spindle speed. when I execute M3 S50 command, it shows following error;
AL26 S-code out of range
AL33 S-Code instruction nothing.

I understand that my spindle speed value is 50 which is not in range. is there any way to change spindle speed range to "50 - 12000 or less rpm" instead of "100-12000 rpm"

Thanks in advance,
Mukesh

[sinha_nsit]

See if S100 with spindle override set to 50% works.

Otherwise, use S100 instead of S50, and adjust your feedrate.

[mukesh_21]

Originally Posted by sinha_nsit See if S100 with spindle override set to 50% works. Otherwise, use S100 instead of S50, and adjust your feedrate.

i have tried the override option but it doesn't work below 100 rpm. and afterall i am running tapping cycle so override function never work in this.
Feedrate adjustment is also not possible as the threaded hole is big and it required very slow spindle speed.

thanks

[John_B]

Try threadmilling instead.

[sinha_nsit]

Why cann't you increase the feedrate, to suit a higher rpm (assuming yiou are in G94 mode)? 100 rpm is not too high.

[underthetire]

Being a 12K spindle, its most likely an integral or direct drive spindle. Even if you changed a parameter to run at 50RPM, it's gonna stall the spindle anyway. Get a better tap and use more RPM, even 100 RPM on a high speed spindle could be bad.

[cnc2149]

At the risk of piling on, I agree that figuring out a way to go 50 RPM isn't desireable. Most FANUC spindle motors have 100:1 regulation ratio (max speed compared to lowest speed that they can hold). A 12000 RPM spindle should be able to regulate speed well down to 120 RPM. 100 RPM is likely do-able. 50 RPM is rather low and may not hold speed well enough. There's a reason the machine builder posts the message of insufficient RPM at 100 RPM. I agree they should tap at a higher RPM.

[beekeeper]

set your spindle speed at 100 rpm then divide the spindle speed by the number of threads per inch will give you your feedrate. A toyota should be fine running at 100 rpm. you didnt say how big of a tap you are running. If you are afraid of stalling the motor I would just run tap deep enough to start the threads then hand tap.

[sinha_nsit]

or use F=<pitch> in G74/G84, with G95.