Spindle ramp-up speeds for 3018 20k spindle

I’ve upgraded to the 20K spindle for my 3018 and have the upgraded power supp;y as well.
I would still like to use the ramp-up spindle settings as I don’t like the jerk I get when the spindle starts (I’m running $30=16000).
Trouble is that even though SainSmart lists the code to use, they don’t tell me how to put it into grbl. Whenever I try, using Candle or UGS I get an error message.
Here’s the recommended code:
G4 P.25
G4 P.25
G4 P.25
Does anyone know what I’m doing wrong? Please use small words as I’m just learning this stuff.
Bill P

This is your max spindle rpm. It can’t have an S in it.

Every website shows the S.
And if I don’t put it in the speed setting in Grbl doesn’t change.
Or do you mean no S after the first $30?

should read $30=4000. No S

This ahould not include the $30 at all for the ramp up code.

Delete $30= and save it as a macro so you can get the spindle up yo speed before stsrting the file and it will ramp the spindle from stopped up to 10,000 rpm

As a seperate line of code you should set $30 to 20000 by sending this command in the console section:

This code needs sent only once thogh, not at the start of each carve… and this changes your spindle max rpm from 10,000 to 20,000 kinda…