Also for this upgrade, there are many Alfawise U10 users that have this problem.
With this upgrade, that will come to an end and remove all frustrations on the Z-axis for all those users of this printer.
Well, lets get started with another upgrade to make this printer better.
As written in my post https://www.thingiverse.com/thing:2865149 there are many flaws that came with this printer.
One of those flaws is:
The Z-Axis always runs out of sync on the right hand side of the printer.
After each print, the z-axis needs to be adjusted so the next print can start.
How to solve this issue:
Depending on the height of your printbed, you need one set of the posted brackets, either the 90mm or the 88.5mm
( One for the left hand side ( LHS ) and one for the right hand side ( RHS )).
Recommended to print both sets in different colors if you only have 1 printer you are working with.
Needed parts and materials:
6x M5x10mm screws ( philips head )
6x M5 T-nuts
4x M3x10mm screws ( philips head )
2x Microswitch of the same type
1x Wire ( Black/Red ) ( i used an old broken USB loading cable of 1.5mtr )
2x a4988 Stepper driver ( recommended Vref = 0.86V per stepper driver )
2x Stepper motor 17HS4401 ( in case as with me, the original stepper motors of the U10 fail )
Heat shrink tubing
1x Dupon connector ( for 2 or 3 wires )
Philips head screwdriver
Multimeter ( to adjust the Vref on the stepper drivers )
Non conductive ( Ceramic ) mini screwdriver for adjusting the potentiometer on the stepper drivers
2x Limit switch brackets ( printed ) 90mm or 88.5mm ( i started with the 90mm ( Yellow ) and ended with the 88.5mm ( Gray )).
Steps for implementation:
Remove the Main Power supply cable from the electronics cabinet ( Safety above all ).
Check the wiring on the left hand side Z-limit switch, on mine it is connected to C and NO. NC is not used.
Solder the wires to the limit switches to C and NO.
Solder a Dupont connector on the other end of the cable of the right hand side micro switch connection.
Use the M3 screws to screw the limit switches to the brackets ( as shown on the photo )
Place the M5 screws with the T-nuts in the brackets ( as shown on the photo )
Screw the brackets in place on the frame ( as shown on the photo )
Root the cable connected to the limit switch on the right hand side of the printer to the electronics cabinet.
Open up the electronics cabinet by removing the 4 screws from the side.
Remove the standard BT7221A stepper driver from the Z-connector on the board
Insert the a4988 into the Z-connector on the board ( same way as you removed the BT7221A )
Guide the micro switch cable into the electronics cabinet and connect it to the Z-Max connector ( only connection open )
Be sure the Dupont connector is inserted the same way as the cables in the X, Y and Z-min connectors ( else you will blow up your board )
Insert an extra a4988 into the E1-connector ( same way as all other stepper drivers ).
Remove the short white splitter cable ( see photo ) from the Z-Stepper connector and detach it from the stepper wires.
You now have 2 loose stepper cables and it is time to do some conversions to the cables.
The conversion consist out of 2 steps
Left motor connector and Right board connector ( E1 ), you can see the conversion in the schematic shown in the picture provided.
Place the connector with the blue wire in the Z-connector.
Place the connector with the Yellow wire in the E1-connector.
If you are certain and confident that all wires are connected correct and properly then you can place back the cover of the Electronics cabinet.
Bolt the cover in place after all steps are taken and the printer is working again ( in case of failure ).
Connect the Main Power cable into the power inlet of the electronics cabinet, no use to turn it on yet.
Time to adjust the Marlin provided with the printer on the SD card.
Before you adjust the Marlin software i recommend that you make a copy ( create a backup ) of the original Marlin.
Rename the Marlin copy to "Marlin-1.1.0-1 Original"
Rename the Marlin you going to use to "Marlin-1.1.0-1 Dual-Z"
In case something goes wrong, you can always fall back to the original firmware provided with the printer.
WARNING!!! to avoid Hugh caps in the text of Marlin, i placed a ' in front of some lines. Please ignore these when changing the firmware.
Steps to what to adjust inside Marlin:
goto the tab Configuration.h
In case a stepper motor runs the wrong direction:
goto // @section machine
// Invert the stepper direction. Change (or reverse the motor connector) if an axis goes the wrong way.
'#define INVERT_X_DIR true
'#define INVERT_Y_DIR false // standard true
'#define INVERT_Z_DIR false // standard true
// If enabled, axes won't move below MIN_POS in response to movement commands.
// If enabled, axes won't move above MAX_POS in response to movement commands.
//#define MAX_SOFTWARE_ENDSTOPS // standard undefined
goto the tab Configuration_adv.h
// @section extras ( Change this section as shown below )
// A single Z stepper driver is usually used to drive 2 stepper motors.
// Uncomment this option to use a separate stepper driver for each Z axis motor.
// The next unused E driver will be assigned to the second Z stepper.
// Z_DUAL_ENDSTOPS is a feature to enable the use of 2 endstops for both Z steppers - Let's call them Z stepper and Z2 stepper.
// That way the machine is capable to align the bed during home, since both Z steppers are homed.
// There is also an implementation of M666 (software endstops adjustment) to this feature.
// After Z homing, this adjustment is applied to just one of the steppers in order to align the bed.
// One just need to home the Z axis and measure the distance difference between both Z axis and apply the math: Z adjust = Z - Z2.
// If the Z stepper axis is closer to the bed, the measure Z > Z2 (yes, it is.. think about it) and the Z adjust would be positive.
// Play a little bit with small adjustments (0.5mm) and check the behaviour.
// The M119 (endstops report) will start reporting the Z2 Endstop as well.
'#define Z2_USE_ENDSTOP ZMAX
'#define Z_DUAL_ENDSTOPS_ADJUSTMENT 0 // use M666 command to determine/test this value
'#endif // Z_DUAL_STEPPER_DRIVERS
Compile the sketch
After compiling is completed you most likely you will see some errors as the marlin is not written and cleaned that well by Alfawise.
Compile it again and it should be free of errors when you ran it the 2nd time.
Power on the electronics cabinet and connect the printer with a USB cable to the computer.
The computer will reserve a port number for it.
If you never used Marlin before:
Go into the extra's menu ( i hope that this is called extra's as mine is in a dutch version )
For board set it to: Arduino/Genuino Mega or Mega2560
For Processor set it to: ATmega2560 (Mega2560)
For Port set it to: the port provided by your system ( not COM1 )
Now that is all set, upload the sketch to the Alfawise U10 and wait till it says Upload completed.
Before you start testing the printer, there need to be done a few other steps.
Remove the gray strip from the 2020 extrusion on the X-axis
Loosen the 4 screws that hold the 2020 X-axis extrusion to the Z-axis carriages ( Both sides )
Lower the heated bed as far as possible ( all the way down )
Place the X-carriage and the Y-carriage in the center of the print area
Press the knob on your electronics cabinet and go into prepare.
Test the movements of the X- and Y-axis with steps of 10mm, move the Z-axis with steps of 1mm upwards (+) to check if the motors run in the correct direction.
If the Z-motors are not responding, then it might be that you need to adjust the Vref on the stepper drivers, if thats not working you need to install 2 other stepper motors ( see list ).
For how to adjust the Vref on a stepperdriver, search on Youtube for "Vref a4988", there is plenty of information about it on the web.
If all motors run in the correct direction, then you are good to go, if not go back into Marlin and invert the motor that is running the wrong direction ( tab Configuration.H - // @section machine )
Upload the sketch again after the adjustments and test the movement again.
Go back in the prepare menu on the electronics cabinet.
Move the Z-axis 100mm upwards.
Time to test the micro switches on both sides of the Z-stepper motors
Home the Z-axis, when the movement starts, activate the micro switches on both sides and see if the motors stop.
If they do, congratulations, then all electronic connections are correct installed.
If not, hit the main power switch to turn the printer off and check the cables connected to the micro switches and check the micro switches self ( 0 Ohm test with the multimeter, can be handy that your multimeter has a beep sound ).
Now you can fasten the cover of the electronics cabinet,
Go back in the prepare menu on the electronics cabinet.
Home all axis.
With the bar still not srewed in place, move the Z-axis up again with 400mm.
Create a slope, lower the right hand side carriage a tiny bit ( like 3mm ) and tighten the most right screw.
Home all axis again.
When homed tighten the remaining 3 screws of the 2020 extrusion back on the Z-carriages, do the left hand side first, then the right hand side.
One more test of the z-axis, move it up with 200mm and home all axis again.
Both Z-carriages should hit the micro switches at about the same time.
Place the gray strip back in place
Now we are good to go.
Time to level the bed.
The method described below is the method i always use.
Heat the nozzle upto 200dgs and remove the filament ( not from the filament run out sensor ).
Be sure the nozzle is cleaned from all filament that will extrude out when heating.
Slice the "test print" ( provided ) with layer height on 0.2, first layer height 100%, first layer width 100%, nozzle set to 200dgs and the bed set to 50dgs and put it on the SD card.
Start the print and wait till the printer starts printing the part.
Stop the print from the menu.
Grab a piece of paper of 0.1mm thick.
The X- and Y-axis should be set free by the stop command and you should be able to move them by hand.
With the nozzle and heated bed on temp, level the bed by hand on all 4 corners untill you have it reasonable flat.
The piece of paper should just touch the nozzle on all corners, not hard scraping ( it's all about feeling the tension on the paper ).
Repeat this "level the bed" process a few times untill you are confident that the height of the bed is set correctly.
Insert filament and start printing the "test print" ( 1 layer only on the outside, cancel the print when done ).
Remove the layer from the print bed and use the digital caliper to measure the thickness.
Use one dimension as reference and carefully adjust the print bed with the wheels so the thickness of the layer is near the same over the entire area to meet equal thickness.
For instance, you measure 0.14mm overall on the print, meaning you are 0.06mm to thin.
This is near impossible to adjust by hand so do the following.
Go into the menu "Control > Motion" of the electronic cabinet and adjust the Z-Offset, start with dialing it in to +0.060mm.
After adjusting the Z-Offset, be sure to press the knob to confirm the settings.
The settings will be written in the Eprom and stay active.
Repeat the print and fine tune the Z-offset with tiny steps
Keep working on the Z-Offset untill you are satisfied with the settings for the first layer to be as close to 0.2mm.
Repeat the measuring of the 1st layer and repeat the step for Z-offset.
You should now have an always sticking first layer without the need of dialing in on first layer height and first layer width.
Do make and finish the test print and provide a photo of it in the makes section.
Test print provided is for a 400 x 400 size print surface.
Congratulations to all of you that managed to implement this upgrade.
The photo provided of the test print is made after dialing in the printer and was printed on a clean glass, without the use of any aditives.
Glass washed clean with soap and rinsed after with clear tap water. After washing the surface, do not touch it with your hands, just dry it a bit with a dish cloth.
3D_PP ( 3D Print Creations ) wishes all the people that are going to use this upgrade ( and others upgrades provided ) for the Alfawise U10, Happy printing.
In case something is written wrong, please place a comment so i can adjust it accordingly, afterall my language is Dutch.
3D_PP is not responsible for any damage / injuries what so ever in any kind of degree.
Building this upgrade is all at your own risk, as it is with all other builds/upgrades you create.
Always shut down the Main Voltage Input when working on Electronic Components.
Know what you are doing, You are working with High Voltages, high temperatures and moving parts.
>>>Take NO Risks <<<