CNC 3020/3040 change board?

[Lol999]

Just wondering about the cnc 3020/3040 variants out there. They seem to require either Mach 3 or Drufel CNC to work, but what would happen if you changed the pcb?
Is such a board available to enable the use say of Grbl and Fusion 360 etc?

[john swift]

I don't see why not if the Grbl board can work with the larger working envolope

going by the photos of 3D printers the 3018 machines they use small plug in 1A stepper drivers like these
https://www.pololu.com/product/1182



removing the stepper driver will make the step & direction signals available to operate replacement drivers that can driver the larger motors used on the 3018 machines

if the Grbl board step and direction outputs are only 3V you may need to buffer them if the new stepperdrivers need 5V pulses
( a PC printer port breakout board should do )

John

PS
which Grbl board do you have in mind ?

PPS
just found this circuit diagram for one version of a Grbl board
with plug in A4988 stepper drivers and a plug in Arduino NANO



PPPS
another Grbl board with a relay to control the spindle motor

https://simple-ee.com/2018/06/20/pro...troller-board/

[Lol999]

Hi John it was a hypothetical tbh. I was wondering if the 3018-Pro board with drv8825 drivers on would do or if another beat existed.
Only reason is I'm likely to be getting the 3018 Pro for my birthday late August but depending on finances might be able to go for something with a bit more muscle power wise and rigidity on the motor housing without having to get into Mach 3 or Drufal CNC.

[john swift]

Not knowing what motors are used on the 3040 machines its hard to predict how well the grbr would drive them

with the stepper driver output limited to 2A
the torque will be limited and the low driver supply voltage will limit the speed you can step the motor

it may be worth looking at using linux instead of a windows PC running Mach 3
not sure of what the free ware is called

John

PS

http://linuxcnc.org/downloads/

this is where we need a linux user

[Lol999]

Hi John ironically I've just found several pages devoted to hacking the 3020.
https://www.instructables.com/id/302...CNC-Shield-V3/
https://hackaday.com/2015/09/08/how-...e-cnc-machine/

[john swift]

it looks like the A4899 Stepper Motor Drivers are better than I thought they would be

after looking at the two links

the TinyG motion controller shown on the hackaday page looks good
the only down side is the stepper driver IC's are soldered to the board
and not an easy DIY replacement

from that point of view the arduino grbl board on the instructables page
has an advantage with the plug in drivers

John

[Lol999]

Yeah part of me would go for the 8825 drivers as they are smoother yet with the smaller increments comes lower torque apparently.
we'll see what the birthday fairy brings and what extra I can add in the meantime.

[Lol999]

Interestingly this seems to fulfil the mod requirements for the 3020/3040 etc for virtually no money:
https://www.ebay.co.uk/itm/CNC-V3-Sh...53.m1438.l2649

[john swift]

yes
that will control the motors just like the tinyG for example
the only thing missing is the FET to switch the spindle motor on and off

with the arduino cnc sheild you have just linked to you can connect either a FET module or relay module to add the spindle on/off control



John

PS

check you don't need to add a 5V supply for the arduino
or 7 to 9V if you use the arduino's built in 5V regulator

the A4988 can use a 35V supply for the motors so if the 3040 cnc control has a 24V supply for the original stepper drivers that can be reused

the supply for the TI DRV8825 can be 8.2-V to 45-V

[john swift]

duplicate post