I have constructed a CD Rom CNC Plotter by using 2 CD Rom stepper motors (sm15dd ) and a servo motor (sg90 ), which are connected to CNC Shield V3. I can move X and Y axes from Universal G-Code Sender with grbl-servo. But I cannot move the servo motor connected to 5V, GND and Z+. I have tried powering the 5V from another power source but it did not help. I suspect that my Z+ pin does not work. Is there a possible way to test the Z+ pin on the CNC Shield? I believe I can test it if I can find the pin on Arduino which connects to Z+ on the CNC Shield. But I could not trace the line on PCB to find the pin. I need your guidance in this direction.
The shield is a stepper motor board, not useful for a servo. Use conventional servo handling. How to make that function via Grbl, I can't tell. Use a stepper instead.
However, you should be aware there are some requirements for this to be done in a manner compliant with the rules of the forum and respectful of the people offering free help:
Avoid convergence
Even when the topics start out on discrete subjects, they have a tendency to converge to parallel discussion over time. Parallel discussions are harmful because they waste the time of the helpers who unknowingly duplicate the previous efforts from the other topic. For this reason, you must manage the scope of the discussion to prevent this from happening. If discussion starts to stray into the territory of the other topic, then redirect the participants over to the other to continue that discussion.
Cross-reference
The readers of one topic won't necessarily be aware of the content in the other. If information in one topic is relevant to the discussion in another, help your helpers by mentioning it there with a link.
I do believe the answer for this can be found with a web search.
Reason is that it is a common configuration and built by many as a first foray into CNC.
There are methods out there to user a NON-modified version of GRBL but often they require more knowledge and even on occasions a better sender program.
Z+ (and Z-) is connected to pin 11 on the Uno unless you are using Grbl and VARIABLE_SPINDLE is enabled in the Grbl config file. Then Z+ (and Z-) is connected to pin 12.
It is not a good idea to power the servo from the Uno 5V or USB.
I would still suggest that this is a continuation of the posters previous topic and would suggest it be merged to understand the progress of his project.
@groundFungus Thank you for your reply. I have tried powering the CNC Shield and using D12 of Arduino for a sweep example with the servo connection given in the above wiring picture. I saw that nothing happened. I was lucky to find a 2nd-hand replacement for the CNC Shield yesterday night. I tried the sweep example on this new CNC Shield and it worked. I have spent more than 1 week to make it work on the broken CNC Shield.
Also sending M3 and M5 by Universal G-Code Sender runs/stops the servo now.
@Wawa I am doing it exactly as shown in my first post. I am powering it from the CNC Shield. I supply the shield with 12V 2A and use 5V and GND pins on the CNC Shield for the servo. MY power supply also has another end with a 5V 2A. Do you think it is better to use it?
The power to the shield blue terminal block only powers the steppers. The 5V on the CNC shield comes from USB or the weak Uno 5V regulator, whichever is connected. If both, the highest. Neither is a power supply for the servo. Use the 5V 2A supply for the servo. Connect the ground from the 5V 2A supply to Uno ground as well as servo ground.
@Ballscrewbob and @pert, let me give you some explanation about my posts and then you can decide what to do (join them, keep them separate or remove them).
As far as I know, there are two typical approaches for making a CNC Plotter project (2 steppers for X and Y axes, and 1 servo for Z axis).
Although both apply to the same mechanism, one of them uses Type 1:
Motor Shield V1 (with L293D)
CNC_Code.ino
Processing (for sending the gcode)
and the other one uses Type 2:
CNC Shield V3
grbl library
Universal G-Code Sender
I have two posts currently running in the forum CD Rom CNC Plotter GCode Problem and CNC Shield V3 Servo Problem, which include questions for Type 1 and Type 2, respectively. In my first post, I had a problem with drawing the picture. In my second post, I could draw the picture but I was not able to raise/lower the pen, which I thought to be a hardware problem. After replacing the CNC Shield with a new one, now I have it running.
You seem to have both types in the original post consecutively.
That said I gave you an alternate GRBL suggestion in here when I could have done so in the original post as part of that topic.
It is quite unusual for the CNC shields to be faulty.
Maybe it is your GRBL settings the "$" values.
They can change whenever you re-flash GRBL and I always recommend you refer to values that you know worked or are correct.
Also different versions of GRBL can use different pin assignments so you would need to refer to the documentation for that specific version of GRBL at its source which is usually a GITHUB repo.
At first, I never suspected that my CNC Shield would be the problem. But when I carefully examined the back side of the PCB, I saw some traces of glossy shapes, which I think are residues of dried solder flux. This made me believe that there has been some repairs before I buy this product. But it has been long time and I do not remember from where I bought this CNC Shield. Anyways, it now works fine. Thank you all.
