Hi guys, welcome to techydiy In todays video I am going to look at
a small desktop cnc machine called the wm3020.
Which with the supplied spindle, can mill aluminium
and other non ferrous metals. All three axes run on hg15 linear rails
And they are driven by 12mm ballscrews with nema 17 stepper motors.
The table bed is machined from aluminium with M6 threaded holes for work holding
And this is how the table bed is attached to the Y axis linear rails
and ballscrew nut. All quite solid.
The machine measures 490 x 470 x 395mm with a weight of 13.8kg
and the useable working area is 290 x 220 x 70mm The supplied spindle motor is a 52mm,
300w brushed unit, with an er11 collet
and I measured the maximum unloaded speed as 10300 rpm.
An optional 65mm spindle holder is available for the installion of a more powerful router
or vfd type spindle motor. The control electronics
are housed in a steel case with a knob to set the spindle speed
an emergency stop switch, home, pause and resume buttons.
On the front there is a usb type B connector for a computer
and a connector for an optional offline controller
On the back we have the connectors for the stepper motors,
limit switches, optional laser module,
spindle motor, Power switch and an iec power connector.
This is what we have under the lid There is a power supply
The stepper motor drivers are located under the heatsink
and then an HK32F103C8T6 Arm cortex 32bit microcontroller.
The control box is connected to the machine by a cable loom
which partially runs through a cable chain. And this is what came in the box
The manual is very good, it covers the machine assembly,
the software installation and initial use.
The assembly itself is really simple The gantry is bolted onto the base frame
You can raise it up on some spacers to make the process easier.
Then bolt on the spindle holder
Install the spindle motor Install the cable chain
and then finally plug in the electrical connectors,
which are all labelled, so you cant go wrong.
Select the power supply voltage Plug in the power lead
the usb cable Release the emergency stop switch
and now we are ready to install the software But before we do that a quick
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The software is supplied on a usb stick The driver and candle were copied into a
directory on the laptops c drive Candle is used to control the
machine and send gcode to it. The device driver was installed
The usb cable was plugged in And we can check that it is working
by running windows device manager Selecting ports com andlpt
And then checking the device status Candle was then run by double clicking
on the grbl control candle.exe file The machine starts in a locked state
to remind us to home the machine So, we press the unlock button
and then the home button. Homing is the process the machine
uses to find its starting position. We can select the step size
and then jog the machine.
Turn the spindle on The speed is controlled
by the knob on the control box rather than by gcode commands.
The grbl settings can be updated by typing commands into the console
$30 is the maximum spindle speed $130 is the maximum x axis travel distance
$131 is the maximum y axis travel distance and $132 is the maximum z axis travel distance
$110, 111 and 112 set the maximum feedrates for each axes.
The height probe touch plate is supplied uninsulated
and sometimes this causes problems, so I have covered the back with some tape.
To configure the probe in candle, go to service, settings
There is an existing probe script
I copy the first part of the script into user button 1
and then enable the user commands under panels Now we can use the probe to
measure the touch plates height One of the supplied v bits is installed
The touch plate is placed upside down on a metal sheet,
so that they make electrical contact. The croc clip is connected to the V bit
And then in candle, user button 1 is pressed to initiate the probe
Once the probe makes contact We can zero the z axis
Jog the z axis up
Flip over the touch plate
Press user button 1 again
And then the z axis coordinate gives the height of the touch plate.
We can now enter the touch plate height into the original probe script.
Use the probe to zero the z axis to the surface of the mdf.
Jog to the front left hand corner
And zero the x & y axes. There are some example gcode
files included on the usb stick, which we can load with file, open
And then send to the machine
Next, I designed a spoilboard in fusion 360 with a 45mm square grid pattern
The spoilboard was made from some old chipboard
And attached to the table bed with tape and mitre adhesive
I used the v bit to create some pilot holes
finished drilling the holes by hand and the spoilboard was reattached using
M6 bolts and washers A 22mm flat end mill
was used to level the spoilboard Zeroing the z axis on the lowest area
If it doesn't flatten the whole surface then I just run the job again.
Now that the spoilboard is level lets try cutting aluminium.
I have created a test model in fusion 360 with 2D adaptive roughing toolpaths
and a 1/8" single flute end mill. All of the tool paths
start with a 2 degree helix, cutting down to the final depth of 2mm
and then cutting the pockets with different
optimal loads and feedrates. The feedrate is calculated based
on the material, the spindle speed,
the endmill diameter and its number of flutes.
To increase the feedrate we could either increase the spindle speed,
use a larger diameter end mill or increase the number of flutes.
The optimal load and depth of cut are limited by the rigidity of the machine
and the power and torque available from the spindle.
Tests like these help to find a good balance between the feedrate and the load
and they also help us to understand the capabilities of the machine.
For the second set of tests I cut another pocket with 1.2mm optimal load,
and then followed up with a 2D contour toolpath with a depth of 0.1mm and a step over of 0.5mm
This toolpath took a total of 3m and 18 secs Then I cut a pocket with 0.4mm optimal load,
which gives a better surface finish to start with
and then followed up with a 2D pocket toolpath with a depth of 0.1mm and a step over of 0.1mm
This toolpath taking 11m and 35s.
Next, I installed a 6mm single flute endmill and increased the feedrate
And finally I tried a 5mm 3 flute endmill
Next, I created a model for a right angle bracket
The holes were cut with bore operations
I screwed down the sheet to avoid having to use work holding tabs
and the outline was cut with a contour operation.
Next up was pcb milling Starting with a simple test pcb,
which was created as an electronic design in fusion 360.
Milling and drilling takes place on the bottom of the pcb
and so the design needs to be flipped So under manufacturing, cam processor,
bottom copper advanced
I selected the "Mirrors gerber output horizontally" button
The same was repeated for drills Then the process button, to save the
gerber manufacturing files to the local disk
Next, I used flatcam to generate the gcode files The final cut depth was 0.04mm in two passes
The spoilboard was resurfaced to make it as level as possible.
Then the copper clad pcb board was attached to the spoilboard with tape and ca glue
An 0.1mm 10 degree v bit was installed in the collet.
The copper layer on the pcb board is very thin, approximately 1.37 mils or 0.035mm
and the board is not flat. So to get the best results,
the height mapping feature in candle was used to measure the heights
in a grid pattern. When its finished we
select the edit mode button and check use heightmap
Candle then modifies the gcode to take account of the height variations
And we can send it to the machine. The tip of the end mill is very delicate,
so a slow feedrate is used to help reduce the risk of it breaking off.
Next, the v bit was swapped for an 0.6mm drill and the height zeroed with the probe
Finally the drill was swapped for a 2mm cornmill
The height zeroed again And the gcode sent to the machine
Next I designed a pcb for converting a pwm signal into
a 0-10V dc output, which can then be used to control the speed of an
upgraded vfd type spindle. To make the design easier to mill,
I have increased the pad sizes and the track widths.
Flatcam was used to create the gcode
And a height mapping operation was initiated from candle.
The gcode was sent to the machine.
And if you listen carefully: The tip of the v bit broke off.
Rather than replace the v bit, I took a gamble,
rezeroed it and started the job again.
This resulted in wider cut widths but it was ok,
because I started with thicker pads and traces.
The v bit was swapped for an 0.6mm drill and zeroed
Then a 1mm drill for the larger component pins
And finally a 2mm cornmill was used to cutout the profile of the pcb.
Next, the components were soldered to the pcb and to test it,
the input was connected to the laser output from the wm3020 control box.
An oscilloscope was connected to the pcb input and output
The yellow line is the pwm input with 1 volt per division
and the pink line is the output with 5 volts per division
As the spindle switches on and the speed increases,
the duty cycle of the pwm signal increases.
and the output voltage rises to a maximum of 9.8 volts.
This can be connected to the 0-10v speed control input
of a vfd power supply to automatically control the speed of a more powerful spindle motor.
Ok, so I think that this is an excellent little desktop cnc machine.
It features linear rails and ballscrews, Which helps to give the machine good
rigidity and accuracy Both of which are important
when it come to milling aluminium. To get the best out of the machine,
it would benefit from a more powerful spindle motor.
the obvious choices are a Makita trim router, or a 65mm vfd spindle motor
which I will be testing in a future video. There are also Laser modules available
to fit the machine. This is the 10w optical
output module, which is quite powerful and capable of cutting through wood.
It fits into the spindle holder and connects to the control box.
I have used lightburn software to control it and if you want to know more,
have a look at the Vasto video on this channel.
The machine is currently on offer for Black Friday at $719
and if you are interested the link is in the video description
If you found this video usefull please let me know in the comments
Thanks for watching, And See you again next time.