Hi Guys, welcome to techydiy.
In this episode we are going to continue looking at the Sainsmart 3018 Prover,
install the software on a windows 10 pc
setup the machine and calibrate it
The first thing we are going to do is unplug the standalone controller
and then plug in the usb cable.
The software & driver are supplied on a micro sd card,
along with a usb adapter so that it can be plugged into a pc.
First, we are going to install the ch340 com port driver
Once that’s installed, we can plug the usb cable into the pc
We can check that the com port is working correctly by running device manager
Expanding - Ports com & Lpt
And then selecting the ch340 com port
The device has been installed as com4 and the device status shows that its working correctly
Next, we need some software to send gcode to the machine.
Sainsmart have included a copy of candle on the microsd card
candle is open source software
And I am just copying into a directory on my c drive
To run candle, open the folder and double click on the grblcontrol candle.exe file.
Next, we need to tell candle which com port to use
Select the service menu, settings
And then under Connection, select the com port
When its first powered up grbl is locked and the status indicates an alarm
This is to remind us to run a homing cycle before we use the machine
To unlock grbl we can either type $X into the console or select the unlock button.
Now we can use the jog keys to move the axes
Set the number of steps for each press of the jog key
And change the feed rate, which sets the speed that the axes will move.
Selecting keyboard control, allows us to jog with the keypad.
Grbl has several configuration settings which can be viewed by entering $$ into the console
Descriptions of the settings can be found on github
It’s a good idea to take a copy of the settings before making any modifications.
I just cut and paste them into notepad.
If one of the axes is moving in the wrong direction,
then the $3 direction port invert mask setting should be modified.
The table shows the setting values and the effect on the axes
The correct value for this machine is 2
And to change the setting, just type $3=2 into the console
The $21 hard limits setting enables or disables the limit switches.
This prevents the machine axes from travelling to far and breaking something.
When a switch triggers, grbl halts all motion,
turns off the spindle and enters into alarm mode.
Before you can do anything else grbl has to be reset and the alarm unlocked
In practice the switch will trip again,
and we will need to reset and unlock a second time.
The $130, 131 and 132 max travel settings
are the maximum end to end travel distance for each axis.
The value for x was 260mm
The value for y 158mm
and z 34mm
Homing uses the limit switches
to accurately locate a known starting position
It’s enabled with the $22 homing cycle setting
The homing directions are controlled by the $23 Homing dir invert, mask setting
The machine was supplied with this set to 3,
so it homes to the bottom left with the spindle up
If we change the setting to zero
then the home position will be the top right with the spindle up.
The dollar 20 setting enables soft limts.
This is a safety feature which prevents the machine axes moving beyond their safe working area.
Soft limits rely on accurate maximum travel settings and homing
When soft limits are enabled,
grbl checks to see if your trying to do something
that would exceed the working space
and if so, issue a feed hold.
The advantage of soft limits over hard limits is that they are preventative,
and the machine position is retained.
The prover is supplied with a touch plate
for automatically zeroing the z axis height.
This can be activated from the z-probe button in candle.
The configuration for the button can be found under service,
settings and probe commands.
It contains a set of default gcode,
which finds the surface of the probe target,
without changing the work coordinates.
This is useful for milling aluminium
or printed circuit boards.
Sainsmart have provided a replacement script
that will work with the touch plate
but first we need to measure its depth
And then edit the script to correct the depth value
Then we can paste the new script in
If you want to keep the original script
then it can be pasted into one of the user defined buttons.
To obtain the best accuracy from the machine
the steps per mm setting should be configured for each axis
The initial values are 800,
which means that the stepper motor takes 800 steps
to move the axis by 1mm.
To calibrate the machine,
move or jog the axis a defined distance,
in this example 100mm
Then measure the actual physical distance moved, 105mm
and finally calculate a new steps/mm setting
by dividing the jogged distance,
by the measured distance
and multiplying that, with the existing steps/mm setting
Let’s have a go at calibrating the x axis
First I put down some tape
and then jogged the v bit to mark the start position
Raised the bit to clear the surface
Jogged the v bit 200mm to the right
Put down some more tape
And marked the end position
I measured the distance moved
which was 202mm
The new steps per mm value was calculated
And then the $100 x axis steps per mm setting
was updated with the new value
Now we can try that again from the same start position
And this time we get 200mm
To calibrate the y axis, we follow the same process.
This time jogging 150mm
The measured distance is 151mm
We calculate the new steps per mm value in the same way as before
And update the $101 y axis steps per mm setting with the new value
Measuring the z axis with a ruler is more difficult
and it’s easier to use calipers or an indicator.
Calipers can be turned into a temporary height gauge
by slotting them into a wooden base
I jogged the z axis 20mm
And the calipers measured 20.14mm
The new steps per mm value was calculated
And the $102 z axis steps per mm setting
was updated with the new value
Next we can check if the x and y axes are at right angles to each other
Jog the axes in a 100mm square and mark each corner
This time I turned on the spindle before lowering the bit
If the axes are at 90 degrees to each other,
then the diagonal measurements will be the same
If they are not the same,
then one of the gantry sides can be adjusted until they are.
A spoil board help prevents damage to the table bed
by allowing you to cut all the way through the workpiece material
It should be surfaced to obtain a consistent depth of cut across the work area
and then resurfaced whenever damage builds up.
These are the dimensions for the spoil board
And the locations for the mounting holes.
The spoil board is mounted with countersunk screws and t nuts,
with the screw heads sunk below the surface.
A 22mm bottom clearing or surfacing bit
is used to level the spoil board
And a 6mm er11 collet is used to hold the bit’s 6mm shaft.
I am going to remove the motor because it’s easier to film.
The collet should just snap out of the holder but sometimes they need some help
The new 6mm collet snaps in
And then the 22mm bit can be installed
Next, we need some gcode to flatten the surface.
I have created a project in easel.
This cuts a rectangular area with a depth of 0.2mm
The rectangle is offset and larger than the spoil board so that the bit reaches the edges
The material size is set.
The bit size is set to 22mm
and the cut settings are 150mm/min feed rate,
120 mm/min pluge rate
and 0.2mm depth per pass
In theory this should take about 25minutes
To export the gcode , select the machine menu,
then advanced,
generate gcode and export gcode
The gcode is opened in candle
The machine is homed
And the x and y work coordinates are zeroed
The bit is jogged towards the centre of the spoilboard
The croc clip for the touch plate is attached
And then the z probe script is initiated
The croc clip is removed and then the gcode is sent to the machine
You can see that the left hand side is lower than the right hand side
and the bit is not cutting into it.
So, we will run it again,
this time zeroing the z axis on the left
This time it has levelled the whole board, so we are good to go.
Ok so that was an introduction to installing the software and configuring the settings.
You can find links to all the things I have shown in the video description.
Thanks for watching and see you again next time.