Comments on: Arduino CNC Shield – 100% GRBL Compatable

By: Bertus Kruger

Bertus Kruger — Tue, 27 Oct 2015 17:36:31 +0000

Restarting the the UNO should display the GRBL version.

By: Bertus Kruger

Bertus Kruger — Tue, 27 Oct 2015 17:31:12 +0000

Sounds possible if the pins can be readjusted in TinyG.

By: Bertus Kruger

Bertus Kruger — Tue, 27 Oct 2015 17:27:20 +0000

Hi Ron. Have a look at Pololu's design notes on the Fault Pin. https://www.pololu.com/product/2133 They Pololu DRV8825 has a pull-up resistor on the Fault pin and is fine with logic voltage as used on the A4988.

By: Ron Wensley

Ron Wensley — Mon, 19 Oct 2015 10:33:26 +0000

Greetings,

You have done a nice job with this board and the instructions. In looking at the schematic I have a concern when using the DRV8825 from Pololu.
The 8825 has a pin labeled nFAULT. This is an open drain output from the 8825. Your board has the pin tied to +5V. If the 8825 signals a fault will this not cause a short of the 5V power and potentially destroy the chip?

Thanks,
Ron Wensley

By: John Meikrantz

John Meikrantz — Sun, 11 Oct 2015 19:38:12 +0000

Question about the CNC Shield and compatibility with Due. The folks at Synthetos are porting TinyG to run on the Arduino Due, and it is compatible with the old 3 axis grblShield.

Would it be possible to run the CNC Shield on Due with the TinyG firmware? I’m thinking it should work, since you are really just extending the Arduino pins to the shield and incorporating the driver circuitry.

By: Ivan Aksenov

Ivan Aksenov — Wed, 30 Sep 2015 14:14:17 +0000

Ah, In re-reading the article I see the connection of PWM to TTL now, thank you! ( http://www.instructables.com/id/Shapeoko-2-Arduino-UNO-R3-grbl-9g-8bit-Raster-Phot/). However, my shield is not showing the “VER 3.10” stamp near the power supply connector like I see in the picture. (can i upload a picture of my board here?). Also, not sure what version of Grbl is running. does $$ show me the firmware? I’ll have to look tonight when I’m home. Thanks for the reply.

By: Bertus Kruger

Bertus Kruger — Wed, 30 Sep 2015 01:34:35 +0000

No…. For the PWM Spindle to work they had to change the pin because not all of them support PWM. Coolant pin is for misters and liquid pumps to keep the cutting surfaces cool. The breakout pins on the Left of the shield can be connected to external drivers like the TB6600.

By: Bertus Kruger

Bertus Kruger — Wed, 30 Sep 2015 01:31:21 +0000

With version 3.10 the Spindle pins has been corrected for GRBL version 0.9. Spindle = P11 and Z-Lim = P13

By: Bertus Kruger

Bertus Kruger — Wed, 30 Sep 2015 01:24:30 +0000

Are you talking about the PWM? The V3.10 and up boards supports the PWM spindle control out of the box and uses the GRBL 0.9 firmware. All you have to do is connect ground and the spindle pin.(Ensure the Laser Diode is the right way around.) To activate the PWM function set the “S” command to 0-1000. Don’t forget to also use the Spindle commands to switch it on – > M3-5.

By: Bertus Kruger

Bertus Kruger — Wed, 30 Sep 2015 01:19:03 +0000

Yes… It should be possible via the breakout pins on the left of the shield.

By: Ivan

Ivan — Wed, 30 Sep 2015 00:39:38 +0000

I’ve made a small 3-axis CNC machine for engraving with a small spindle and 300mW laser diode. I want to engrave raster images and added a Laser Diode Driver with TTL modulation. I am not sure how to connect the TTL, -ve goes to ground but which pin on either the Arduino CNC shield or Arduino UNO will provide the modulation for TTL +ve?

By: Gailen Jensen

Gailen Jensen — Sat, 26 Sep 2015 21:13:26 +0000

What’s different electrically with ver. 3.10 and ver.3? The “Spindle Enable” still connects to pin D11, right?

By: ordy

ordy — Wed, 23 Sep 2015 18:24:06 +0000

for what i understand in cnc Shield v3 it needs to be swaped the pins for grbl 9 is this possible to do on the code of grbl or it needs to do changes on circuit to swap the pins 12 and 13?
also can u tell me what is the coolant pin for, and also if is possible to use other drivers like tb6600 on cnc shield v3?

By: Gui

Gui — Wed, 23 Sep 2015 13:10:26 +0000

Can i connect tb6600 divers on cnc shield v3.?

By: Bertus Kruger

Bertus Kruger — Mon, 14 Sep 2015 09:33:58 +0000

The CNC shield has the end-stops already in parallel(2 per axis). Make sure you use shielded cables and that the machine is properly grounded.

By: Bertus Kruger

Bertus Kruger — Mon, 14 Sep 2015 09:31:25 +0000

I prefer the the Raspberry Pi version because its plug and play.

By: ChaOsRul3z

ChaOsRul3z — Sun, 13 Sep 2015 20:48:26 +0000

What would be the recommended board to pick the Arduino CNC Shield V3.10 or Raspberry Pi CNC Board Because I dont know what is the best option?

By: Eric A.

Eric A. — Sat, 12 Sep 2015 06:05:04 +0000

I am having trouble with my limit switches, using NO type switches and have one set of leads going to each pin (NO/COM) but it’s giving me a false trip or just locking up GRBL entirely. I read a bunch of stuff about the pins being switched so I’ll try that, and also something about wiring the hard stop switches (one on each side) in parallel.

If In parallel, which pins do I connect to (+ or -)

By: Ianlh

Ianlh — Thu, 10 Sep 2015 06:59:16 +0000

Thanks for clearing that up, one is to be ordered

By: Bertus Kruger

Bertus Kruger — Thu, 10 Sep 2015 02:38:36 +0000

Thanks for the feedback and support.