Now that the Eggbot is running, I have noticed that the "print" is quite shaky.
My first assumption was that the mechanics were "vibrating".
On closer inspection, the motor drivers came into consideration.
So solution sought and found.
The Trinamic TMC2208 drivers are compatible with the 4988 Pololu drivers.
These interpolate the steps to 256 steps and can be used after a small modification
be exchanged for the 4988.
To do this, only three pins on the TMC need to be cut and the current to the motor set.
I have adjusted the current/voltage on the potentiometer to 0.6 volts so that the steppers run quietly and smoothly.
Now only the servo can be heard when printing!
In addition, the print image is significantly improved, hardly any trembling at the pen.
On the pictures you can see two eggs in comparison, on the left printed with TMC2208 and on the right with the old 4988 drivers.
The TMC 2208 is available from different manufacturers and in different variants.
I used the TMC from Bigtreetech in V 3.0 with potentiometer !
There is also a version without potentiometer, which is not suitable.
As you can see in the pictures, the three protruding pins at the top are cut off at the bottom of the driver.
That was all the modification, apart from setting the voltage on the potentiometer to approx. 0.6 volts.
Nothing needs to be changed in the software or on the board.
Attention !!! When mounting the driver, make sure that the driver is mounted the right way round, the EN pin marking must be at the top left !!!!
Both the first TMC and the Arduino crashed on my first attempt because I was asleep !!!!
Since Thingiverse still wants an STL file, I have attached the vial holder, which I glued to the upper pin arm of my Eggbot to adjust the pins.
Description : https://www.thingiverse.com/thing:4704134
Now that the Eggbot is running, I found that the "print" is pretty shaky.
The first assumption was that the mechanism "oscillates".
Upon closer examination, the motor drivers came into consideration.
So solution sought and found.
The Trinamic TMC2208 drivers are compatible with the 4988 Pololu drivers.
These interpolate the steps to 256 steps and can be used after a small modification
exchanged for the 4988.
All you have to do is cut three pins on the TMC and set the current to the motor.
I adjusted the current/voltage on the potentiometer to 0.6 volts, so the steppers run quietly and quietly.
When printing, only the servo can be heard!
In addition, the print image is significantly improved, and there is hardly any trembling on the pen.
In the pictures you can see two eggs in comparison, left printed with TMC2208 and right printed with the old 4988 drivers.
The TMC 2208 is available from different manufacturers and in various variants.
I have the TMC from Bigtreetech in V 3.0 with potentiometer! taken.
There is also a variant without a potentiometer, which is not suitable.
As can be seen in the pictures, the three protruding pins on the underside of the driver are cut off here.
That was all of the modification apart from setting the voltage on the pot to about 0.6 volts.
Nothing needs to be changed in the software or on the board.
Danger !!! When installing the driver, make sure that the driver is installed in the correct direction, the pin marking EN must be on the top left !!!!
I lost the first TMC and the Arduino on the first try because I slept !!!!
Since Thingiverse absolutely wants an STL file, I attached the dragonfly holder, which I glued to the upper pin arm of my Eggbot to adjust the pins.
Description : https://www.thingiverse.com/thing:4704134