Ask Grbl CNC questions here.

Thanks, I will use bidirectional comms.

 

Hello everyone, I have a makerbase mks dlc32 which uses Grbl. Unfortunately, both Y-axis motors run on one driver, so the full power cannot be accessed.

So I'm looking for a way to make the unused z-axis a clone of the y-axis.

Is it possible to do this in Grbl and if so, could I get detailed instructions for it?

 

Hardware, not software. Split out the step/dir/ena lines from the single Y axis to the Z axis driver as well. Now it's another Y axis. If you need the motor direction reversed because the two motors are mounted symmetrically, just flip the wiring direction of one of the coils of one of the motors.

 

Is there a manual or a video to see how it's done?

I'm pretty new at cnc.

 

Depending on board layout physical change may be easier, however you can also edit pin assignments in grbl.

 

As an edit, i also believe that most boards that use dual drivers for z or y for example do it electronically. Of the top of my head thinking you can just tap onto step and dir pins and cut z traces. You will have to verify but i believe enable usually is not implemented "correctly", its just shorted. For ex

 

Either one or the other way, I need to know how I could do it.

 

Find pinout of motor driver online. Then figure out which pins are dir, step and enable. Verify if enable is actually used or just shorted(i believe to ground) if not used then On z cut traces on dir/step, then jumper each from existing y to old z drive. Check spin direction and if not correct swap one pair of coil wires on z so it moves correctly.... of enable is not grounded and is actually traced back to a pin on mcu then cut z trace and jumper it as well....... this is pretty much what i said before, maybe a little more step by step...

 

Unless someone has the exact same machine with the same controller and is doing the same thing, there are unlikely to be step by step guides. You need to learn how the general principle works, then apply that knowledge to your specific problem. That's how all of hobby engineering and electronics works.

I described the two stages in enough detail to get a pretty solid start on Google without too many missteps or false positives, but unless you actually know the general basics of 1) how grbl works and its I/O, 2) how stepper drivers work and their I/O, and 3) how stepper motors work and how they're wired, opening up a machine isn't a great idea *even with* step by step guides. Things can and do go wrong, and you have to be able to observe and diagnose on the fly.

If you run into a *specific* issue and struggle to diagnose it, people are available to help with that, but this is a bit of a "how to do my entire homework" problem.

 

Best idea yet..... I know i use the prev version of black box and it works great.... At some point i may try x32..... I would like to not only use it but run it thru its paces on my various machines. Plasma table, cnc lathe, cnc table.

 

Hate to ask such a basic question, but; My CNC is grbl controlled installed on an UNO.
When I download a Gcode file from Vectric to my Open Builds controller is the file
loaded on to the UNO, like a normal Arduino sketch, or does the controller send the
code, one line at a time, to the UNO??

 

Thanks.

 

Are there grbl compatible boards other than the UNO with more flash memory??
Apparently grbl uses 92% of the UNO's memory and triggers a warning "low memory
available, stability problems may occur". Their is a larger capacity UNO but it has wi-fi
which I don't really want.
Thanks

 

There are several board running grblHAL that have significantly more memory. Check out the Openbuilds BlackBox [edit] My response was silently edited by someone who is not me to say that I recommend an open builds product.[/edit]

 

Thanks everyone.

 

Hello ? I am using grbl 1.1 with stm32f407 of thomas project and controlled with grbl plotter software but I have some errors like:. Can anyone help me ?

 

Hello All,
Im almost complete with my first plasma table for my metal shop. I have chosen to use the Blackbox 32 for the controller.

I have customers that send me drawing packs with DXF, NC and NC1 files. If I upload their NC or NC1 files into the Openbuilds controller, it does not read it correctly. I'm assuming this is due to the NC1 file is being exported from Mastercam and they do not export with grbl post process.

Is there anything I can do on my end to take the NC or NC1 files they give me and convert or change them to run on my controller without having to run the DXF's through CAM again?

I have attached a sample code from my customer.

 

That's what I thought. So there is no way to take this file and "modify" it for grbl as it is? Basically, there isn't a program to open it and post-process it again with grbl, if that makes sense.

I would have to run the DXF files through CAM again on my own, and post-process it with grbl correct?

 

Thank you!

 

Hi all, I have an MKS DLC32 v2.0 running the MKS version of GRBL_esp and TMC2209 motor drivers.

One thing that I can’t for the life of me figure out, is how to set the current on these drivers as they have no trimpot.

I’m sure current is limiting my speeds as the nema17 42mm motors stall out under load @ 1,500mm/m and I’m sure they can go faster than that. I’m using 1/8 micro stepping configured via the jumpers on the controller.

Is there a GRBL version of Marlins M907 to set motor current?

 

I don't think you can set the amps in GRBL.
Why don't you try out one of the non TMC drivers and set the higher current, just to see if it will make a difference in the speed.

On the other hand, you really need a silent stepper on a CNC machine? The only time I hear the stepper is when I jog, which is almost next to nothing compared to the time the machine runs. Once I cut stuff it's so loud, the bit cutting and the vacuum running (I have a spindle that is by far not as loud as a router), I don't hear the stepper at all.

 

Both GRBL_esp and grblHAL allows setting the current for SPI or UART controlled Trinamic drivers. However, the MKS DLC32 v2.0 board is not wired for that.
Anyway, it should be possible to set the current by trimpot. E.g. the Watterot TMC2209 drivers has the trimpot on the underside of the PCB, there is a small hole near the VM pin for accessing it. Check the datasheet for the brand you have, they might not be configured/configurable for standalone mode. If so, IMO, they are not suitable for the MKS DLC32.

 

Thanks gents, mine came with the 2209’s but I do have some 5160’s with trim pots I can swap in.

edit: is there a good guide on how to set the current manually via trim pots? I’ve always had software configurable drivers via Klipper in my 3D printers.