Do I need a pause after sending a mn S command?

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Mikehell
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Do I need a pause after sending a mn S command?

Post by Mikehell »

Looking at changing the GRBL post processeor (Inch) which seems to get ignored in favor of the mm one.

I'm just wondering... If my spindle has a 12 ramp up to speed, do I need to add a 12 second pause after the speed command, or will the controller know to wait for the spindle?

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TReischl
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Re: Do I need a pause after sending a mn S command?

Post by TReischl »

Just give it a try and see what happens.
"If you see a good fight, get in it." Dr. Vernon Jones

ger21
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Re: Do I need a pause after sending a mn S command?

Post by ger21 »

I doubt that GRBL knows how long to wait, or if it would even wait at all.
Other controls, like Mach3 and UCCNC, have settings for this.

But why does it take 12 seconds for your spindle to get up to speed? I prefer 2-3 seconds.
Gerry - http://www.thecncwoodworker.com

wb9tpg
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Re: Do I need a pause after sending a mn S command?

Post by wb9tpg »

My GRBL didn't wait so I added a 3 second delay (G4 P3) to the following places

+---------------------------------------------------
+ Command output after the header to switch spindle on
+---------------------------------------------------

begin SPINDLE_ON

"[S]M3"
"G4 P3"
+---------------------------------------------------
+ Commands output for a new segment - toolpath
+ with same toolnumber but maybe different feedrates / speeds
+ Used when you save multiple tool paths in a single file
+---------------------------------------------------

begin NEW_SEGMENT

"G0Z[SAFEZ][S]M3"
"G4 P3"
Gary Mitchell
Kentucky, USA

Mikehell
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Posts: 197
Joined: Wed Mar 22, 2017 9:34 pm
Model of CNC Machine: eBay special China 3040

Re: Do I need a pause after sending a mn S command?

Post by Mikehell »

ger21 wrote:
Thu Jul 30, 2020 12:06 pm

But why does it take 12 seconds for your spindle to get up to speed? I prefer 2-3 seconds.
12 is the default on a 1.5kw Chinese spindle / VFD kit. Just using the 12 seconds as an example. I'll most likely change that setting to something lower. That's the reason for the question. Wondering if I'll need to keep tweaking the PP while I get the VFD settings dialed in.

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