[grbl Issue#1259] Feed Rate in inch/min regardless of G21 Command?

#1 – chamnit 于 2017-07-05

You have to lower the planner minimum speed as well to go below 1mm/min.

#2 – DeltaPrinter88 于 2017-07-05

I just want to get to 1mm/min, not go below. I’ll look into the planner speed though, thanks!

#3 – chamnit 于 2017-07-05

@DeltaPrinter88 : You should be able to get 1mm/min without AMASS enabled. And there is no chance that Grbl can misinterpret a distance with G20 or G21, otherwise there would be a ton of people with problems. I would check if you truly did disable AMASS correctly. You may have edited the wrong config.h file. It should be the one that was copied to your Arduino library folder.

#4 – chamnit 于 2017-07-05

@DeltaPrinter88 : BTW, 4 steps/sec gives you about 240 steps/min. At 80 steps/mm, you won’t get below 3 mm/min.

#5 – 109JB 于 2017-07-05

Are you in G93 inverse time mode? If so, then your commanded line (G21 F1 X25.4) would be telling Grbl to move the X axis 25.4mm and take 1 minute to accomplish it.

#6 – DeltaPrinter88 于 2017-07-05

Thanks for the quick responses guys.

@Chamnit: you know, I really may have been editing the wrong config.h file location…:D oh boy! I’ll update when I’m home in an hour.

#7 – DeltaPrinter88 于 2017-07-05

Update: Thanks Chamnit, you caught my silly mistake. I had indeed been updating my backup file of grbl instead of the one in my arduino library. Such a rookie mistake! My 8W laser is now happily cutting through 1/8″ acrylic at 1mm/min….which may take a while, but beats buying a more expensive machine.