Hey @ecasyp!
I am also building a pen plotter, and encountered same problem. Can you please provide the circuit diagram for the servo? And guide me?
I will be very thankful to hear from you.
Give me a day or two to get this drawn up for you. I will need to look at the plotter to get a diagram drawn.
I will say though, we haven't used this much since I got finished building it. College started back and that has taken away the majority of my free time. I have a few finishing touches to actually have it finished, I also plan on building a tool holder for a dremel. I will probably be doing away with the servo and just making an interchangeable tool holder for both a pen and a dremel. I ordered a lead screw and rail set a few weeks ago so I could design a new Z-axis, and just haven't had the time to do it.
Thank you for responding
SUCCESS!
The servo motor now works. I had download the modified version of grbl. The problem was that, the arduino ide was uploading the original grbl version instead of the modified one. So I removed every other grbl library and only kept the modified grbl, and uploaded it.
That was the most aggravating part for me. I didn't realize that you had to remove the original GRBL file and replace it with the modified version. I also had to change a few things in the GRBL-Servo file before I could get mine to work, I couldn't tell you what I had to do though.
In my engineering class we are learning on Arduino boards currently; the teacher said you learn two languages when learning to write code, typically C++ and profanity. When I built my pen plotter over the summer I didn't realize we would be learning how to code and control with Arduino boards this semester, I built it as something to play around with with my son. I have been able to hep a lot of my classmates with the easier coding problems they have. I can dumb it down a little it for them so they understand it better, because I spent numerous hours getting frustrated with it over the summer. At one point I got so frustrated with it I almost abandoned the entire project, but I didn't mess with it for a few days and bam, I got it to work.
Anyway navixc I hope you enjoy your pen plotter.
hi guys, i have the same problem with the servo not moving, x and y are ok. i installed this file for arduino. GitHub - arnabdasbwn/grbl-coreXY-servo: grbl 0.9i with Servo Motor support and CoreXY configuration Used For Crazy Engineer's Drawing Robot
Hey @sailorretired
I would recommend this grbl GitHub - robottini/grbl-servo: grbl 0.9i with Servo motor support
Here is what I did
Remove every other grbl library from Arduino IDE, except the one given above, then upload it. It is in Documents/Arduino/libraries. There is a problem in Arduino ide that it uploads the original grbl instead of one given above.
i loaded the grbl but the axes move diagonally when i press X + or Y +. the Z axis does not move 
i use universal gcode platform.
@sailorretired did you delete the original GRBL file? That was my biggest issue when I was trying to get mine working. Once I deleted and replaced it with the modified GRBL file it started working.
i deleted the files in the library folder. it's correct?
That is what I had to do and I was able to get it going after that.
Now do the following:
- Download the grbl that I recommend earlier and extract the zip.
- Copy the 'grbl' folder from the extracted folder.
- Paste it in the 'libraries ' folder.
- Open arduino ide and go to
File>Examples>grbl-servo-master>grbl upload.It willopen a new window. - After that, select com port and click on 'upload'.
I have done all the steps but clicking on the single axis moves diagonally and the Z axis does not move. if I insert this gbrl GitHub - arnabdasbwn/grbl-coreXY-servo: grbl 0.9i with Servo Motor support and CoreXY configuration Used For Crazy Engineer's Drawing Robot the movement of the axes is correct but the Z axis does not move. damn
@sailorretired are you using a CNC shield board on top of your Arduino? How is everything wired?
Try using this GRBL file https://github.com/bdring/Grbl_Pen_Servo and move your white wire from the Z+ to the SPN EN. It uses the spindle enable to make the servo activate, the Z+ doesn't work because those are for limit switches. Try that and see what happens. Post #9 is my wiring. The blue and green are for limit switches in my picture.
even with this grbl the axes do not move individually
if pressing X + or Y +. when I press Z + or Z- I receive an impulse from the motors but nothing from the servo, even with the other gbrl it is the same. I saw that in your photo you have a bridge on EN / GND that I don't have, I don't know if it can be of any use.
Honestly I don't know that the ENB/GND bridge does anything.
What controller/ software are you using to try to control the arduino/ cnc shield? It may be a setting in it that needs tweaked. UGS is the one I use when I have time to play with my pen plotter.
i also use UGS
In UGS under the machine tab at the top, click on Edit Macros at the bottom of the list. In the pop up window go to the UGS tab and then select Auto Leveler and see what your Z height is. Mine is -1. For my machine if the number of steps is at zero or above the Z (servo) will not function. I hope this helps.
nothing has changed 