Mini-Prusurinha Printer
A Funny Tiny Prusa Printer — Episode 1 — Ardu_Serie # 78
Hi, This is Prusurinha v1!
It’s a tiny printer; A Device for learning 3D Technology; Let’s see how it works using Arduino Micro, Processing, Inscape Apps. We’ll see G-codes, L293D Motor Driver, and more…
Welcome!
Fig 3. Video showing Prusurinha v2 kicking and alive! Servo is not implemented yet ;)
The goal is to build a 2-D printer as quickly as possible in order to check assumptions and move forward to 3-D.
I’ve planned, did, checked, adjusted, this contraption, and now eventually re-planning, fixing, improving, and sharing this experience about 2D technologies in this series of posts so you can make the same, or give me feedback — See this cycle or infographic from Jeremy Blum depicting what I trying to say…
This printer is J3’s abre-alas (as we used to call a parade-car-opening the allegory of samba schools that Rio’s carnival is famous for) contraption for 3D tech.
Let’s get it on ;)
Materials needed:
2 x L293D Stepper Motor Driver;
1 x Arduino Micro;
2 x DC 5V 2-Phase 4-Wire Micro-step Motor Mini Slider Screw Stepper Motor;
1 x Pliers and cutters;
1/2 x meter Cable Manga (commonly used in communication, signal transfer);
2 x Pcs Double Sided PCB Board Prototype;
1 x crosshead screwdrivers with diameters 2.5–3 mm ;
1 x Table vice;
1 x Dremel tool;
1 x USB Meter, Digital Multimeter;
Bipolar and Unipolar — The differences
There are two types of stepper motors: the unipolar stepper motor and the bipolar stepper motor.
A Unipolar stepper motor has current flowing through each of the coils in a single direction.
The unipolar stepper motor operates with one winding with a center tap per phase.
- Unipolar — the current flows only in a single direction
- Unipolar — make precise angular movements;
- Unipolar — use 2 independent windings with or without center tips;
- Each section of the winding is switched on for each direction of the magnetic field;
- Each winding is made relatively simple with the commutation circuit,
this is done since the arrangement has a magnetic pole which can be reversed without switching the direction of the current;
Three leads per phase and six leads for a regular two-phase stepper motor.
You will usually see that both these phases are often joined internally,
this makes the stepper motor only have five leads.
The Bipolar stepper motor has current flowing in both directions of the coil.
In this project, we will use this one: 4-wire Bipolar Motor:)
As Stepper Motor Used In This Project
Bipolar - Features:-This types of the motor need the right sequences firing to function properly;
-The wrong sequence will cause the motor to only step back and forth;
-It is a 4-wire motor — It is a Bipolar one, again;
-Bipolars are generally better than Unipolar;
-Bipolars have more torque;
-Bipolars are more efficient;
-Bipolars must be controlled precisely;
-In Bipolars the driving current in each winding run in both directions;
-The controller will be used to activate the drive transistors in the proper order;
L293D — Motor Driver Device Pinout
This is what the industry recommend the use of this drive:
What takes time to me was to discovered and pay attention to the pin 8; This is the motor supply; Use DSS! What the…DSS?
Preventing Brownouts
Design Split Supplies (DSS) — One for Electronics and one for the Motors;
This is critical for this application, as most USB Laptop drive only gives us roughly .5 mA, and theses two Stepper Motors will need about 1 A.
So, Split the supplies!
[TODO: MAKE A SKETCH IN FRITZ EXPLAINING THIS CONCEPT]
Here is my rock diagram for your references, sorry for it ;)
Please see that Arduino gives us pins’ sequence: 2,3,4,5 and 15,14,16 and 10.
Take extreme care on the wiring!
Understanding the Motors and Drivers — Driving Recommendations
My approach was:
First, make 1 Stepper run in a breadboard; See my test below:
Here is the code I used to test my Prusurinha v1:
Then 2 steppers:
See that both motors worked together and draw a current of about 700mA.
Then I make a handmade PCB:
Both motors worked, individually :/ but something must be wrong: Each motor draws an Extratosferic 600mA!
As the first problem, I identify short circuit made when fitting the motor in Styrofoam. The wires must be perfectly separate of one from another.
It takes me days to debug this circuit, and what I found too is that I did not make a DSS (see explanation above). The power for the L293D chip must be separate from that one that goes to Arduino. Arduino must be alone in his USB feeding ;) Just connect all GND cables and you are ok!
Then I split the supply and it worked like a charm.
n the next Episode, We Gonna Bring the G-Code, note what went wrong in this project (so you can avoid the 10 most common pitfalls), explaining all the codes that make this type of mini-CNC work (Arduino & Processing) and make Prusurinha v2 kick and alive!
Bye for now! Be tuned!
Download All Files For This Project
Related Posts
78 ° Mini-Prusurinha Printer — A Funny Tiny Prusa Printer — Episode 1 — Ardu_Serie # 78
79 º Prusa Went Wrong — Mini-CNC Project — 10 Most Common Pitfall YOU CAN AVOID — Episode 2 — Ardu_Series #79
Related Posts
78° Mini-Prusurinha Printer — A Funny Tiny Prusa Printer — Episode 1 — Ardu_Serie # 78
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Credits and References
How to Make a Homework Machine for Students by TecH BoyS ToyS
Invent to Learn: Making, Tinkering, and Engineering in the Classroom Book by Gary Stager and Sylvia Libow Martinez
Stepper Motor Driving With Peripheral Drivers (Driver ICs) Application Report by Texas Instruments
What is a Stepper Motor? By Adafruit
Arduino PRO MINI — How to upload code
