Question: I just hooked up my spindle (OpenBuilds Ox with TinyG v8,

Question: I just hooked up my spindle (OpenBuilds Ox with TinyG v8, latest firmware) and I can speed up the spindle with M3 S10000 and slow it down with M3 S0, but it never stops. Even M5 command leaves it running, the same as M3 S0. Is this the expected behavior? It seems like I should be able to completely stop it, not just go from slow to fast.

If you send those GCODE commands with a different sender or utility, does it do the same thing?

ChiliPeppr doesn’t rewrite these. It just passes them straight through. So this would seem to be something with your controller and the PWM being sent to your spindle. I have heard lots of folks say there’s not a standard for the PWM on spindles. The Synthetos guys might have more ideas. @cmcgrath5035 may have ideas as well.

James, read through this item, I believe it will answer your needs

@cmcgrath5035 Bingo! That was it. I just sent the command, “$p1pof=0.0” (sans quotes) and now it shuts off completely when I send the M5 command. Thanks!!

Good news!. Remember that the default $p1pof=0.1, so each time you load new FW you will need to reset this parameter as well.

@cmcgrath5035 will do, thanks! Aside: Not using 0.0 seems like an odd default. Perhaps this is only because “$p1pof=0” doesn’t work? (while “$p1pof=0.0” does)

@SirGeekALot I’m not sure, I assume it has to do with some legacy factory test bed or an application or interface where that is the correct value. I assume 0.0 is required because the parameter is by application a decimal fraction and 0 defaults to an integer, maybe. I only know 0 does not work by experience.

@cmcgrath5035 Actually, it looks like “$p1pof=0” works just fine. Perhaps this was a bug in earlier builds, but I have the very latest firmware (440.20) and it seems to work just fine.

@SirGeekALot Interesting, I don’t recall if I was playing with 440.20 or a G2 build (83.09). Of course I may have fat fingered something.