Hi, this post is to share my (short) experience with my new machine bought on Aliexpress from ChinaCNCzone factory store end of August 2019 (2245 USD, 4 axis and pump).
This is the DSP version with a stand alone controller with SD card. The controller is SMC4-4-16A16B.
No need for a PC. Just put the gcode on the SD card.
This is my first CNC and I am a total newbie in CNC, but with lots of experience in 3D printing. My background is in electronic engineering.
The machine arrived fast by TNT to Switzerland in a very good wood box and it has been easy to assemble it, no real need for instructions.
Mount the spindle, the 3 stepper motors, plug the cables in the controller connectors (all marked) and voilà.
The user guide for the controller SMC4-4-16A16B can be downloaded from internet, it seems to be quite popular.
Do not look for CNC6040 but look for SMC4-4-16A16B.
A lot of videos on youtube also.
It is not really a problem to get used to this controller, XYZ zeroing, using the Z probe etc. Most of the keyboard has no use yet.
My first model milling went very wrong.
There was a quite big drift from layer to layer, say 3mm, on the X axis.
It took me time to understand that the drift was continuous during operation and not from layer to layer (noob ;-)).
The best way I've found to show the drift is to zero the tool in the air, use foam, make a hole under the XYZ zero in the foam using the manual controls (Z only), then make the tool fly in the air with a gcode program, pause the machine, tell it to go to zero, lower the tool close to the first hole by hand and compare the position of the tool with the initial hole then restart the gcode execution.
My first reaction was to swap X and Y. Same problem, now on Y. So it was on the control line of the X channel and not on the machine.
I tried without the spindle running (and the pump off ...) : no drift.
So it was an interference from spindle to X channel, I thought.
I took the spindle cable out of the cable path, since all the cables are tight together.
Same problem.
Tried with a ground cable connected to the spindle body.
No progress.
Then I opened the control box and identified the X channel controller, on the left.
It was very close to the pump supply cable. Mmmm, it was maybe a pump to X channel interference !
So I tried with the spindle running at full speed and no pump (there was water in the spindle, no risk) : no X axis drift !
To avoid spindle heating, I was running the pump when I was checking the zero, gcode paused.
Now, I have rerouted the pump wire inside the box and put a capacitor on the pump connector, and everything works a charm.
By the way, I don't like that pump too much. A submersible pump for fish tank looks much better because it does not need to be primed, and there is no noise and no interference of course because it is supplied directly from the mains.

At the end, this machine looks pretty well built, the electronics look professional, well organized, and except for this stupid pump interference story, it would have worked a charm out of the box.
At this stage, I am happy with the machine.