Cheap Braille Embosser (La Picoreuse)

Presentation

"La Picoreuse" is a cheap (75€), easy to build A4 braille embosser.

This project aims to serve as a first step or a basis for reflection for other makers in order to provide an alternative to very expensive market embossers (3000€)

The idea of this project is borned to respond to the needs of the ParACheval association

The cutting and soldering part could be realized thanks to fablab-sud31 (Cintegabelle)

Sources

OpenSCAD Sketch and DXF files: thingiverse

All source files: github

Step 1: Presentation

Step 2: Components (≈ 75€)

Frame

• MDF - 479*302*6mm (5€)
• MDF - 224*204*3mm (3€)
• Piece of Bicycle inner tube
• 2x Old printer metal rod Ø6mm
• 1x Old printer metal rod Ø8mm
• 1x bronze ring - BNZ8-10-6 (1.5€)
• 3x bronze ring - BNZ6-8-8 (5€)
• 5x Nylon cable tie (0,5€)

Motors

• 2x Nema17 steppers (20€)
• Pulley / Belt - GT2 20 (4€)
• Connection Ø5mm to Ø8mm - Ø14mm extern diameter (2.5€)
• End-of-travel switch (0.5€)
• Solenoid 30 x 15 x 13mm (2.5€)

Electronic

• Arduino Uno (10€)
• Motor shield (type Adafruit Motor shield V1) (9€)
• TIP120 NPN (0.5€)
• 1N4004 400V 1A Axial Lead Silicone diodes (0.05€)
• Resistor 2.2kom (0.05€)
• 12v transformator (10€)
• 12v jack femmal connector (0,5€)

Step 3: Prepare Boards

Cut frame

Download the 2 files and cut them using laser cutter (cnc may broke some of the small parts)

Indicative laser cutter settings (100W laser cutter)

• for 6mm MDF: 13m/s at 80% power
• for 3mm MDF: 30m/s at 80% power

If you are looking for up-to-date files or if you need to adapt them to a particular purpose, you could download OpenScad sources here

Step 4: Prepare Board

Prepare boards

Sand the boards G and E and fix 5mm bolt to E board (could be done later)

G is sanded to avoid blocking the paper

E is sanded to avoid blocking solenoid wires

Step 5: Adjust the Belt Length

Adjust the length of the belt

Block one of the ends of the belt with a nylon cable tie (make sure to put the head of the collar in the plane of the belt)

Follow the path indicated on the picture attached to the belt (put 2 nuts on the big axis to be sure to have the right dimension)

Attach the second end with a nylon cable tie

Step 6: Assemble Solenoid Support

Assemble the solenoid support

Attach belt connexion bold on each side of the solenoid.

Attach bronze ring with nylon cable tie.

Attach Solenoid with bolt. Be carrefull, if the bolt is too long it may cramp the solenoid moves a bit. If so add some rings to reduce the thread length

If the belt is already at the correct length you could add it at this step.

Step 7: Assemble Main Frame

Assemble main frame

Screw the Arduino card to the board H

Embed boards F, G and H in board B

Embed board C

Slide board F so that it blocks both sides

Step 8: Leaf Drive System

Leaf drive system

Nest the leaf drive system

Notice: If your leaf drive system is not the same size, you may have to adapt board G in OpenScad sketch (here)

Step 9: ​Damping Rubber

Damping Rubber

Insert the damping rubber of the punching system. To increase rigidity it could be useful to glue last layers of rubbers togethers.

Step 10: Connectors

12v connector

Add 12v connector on C board

End-of-travel switch

Add end-of-travel switch to C board. To build a more secure machine, it is also possible to add an other switch to B board.

Notice: in the video it is added to B board because it is another version of the machine

Step 11: Buid X Axis

Build X axis

Add D board on right side.

Slide the 6mm metal bars starting with the bottom one.

Step 12: Install Belt

Install the strap and make it protrude into the notches on each side

Step 13: Electronic

Connect wires as shown in the shema.

It may be useful to use pluggable connectors for solenoid and end-of-travel switch.

Step 14: Add Electronic

Connect electronic

Plug motor shield to Arduino board

Pass Y motor wires throw C and D boards holes (the X motor wires must stay in)

Add solenoid control part

Screw the power wire (motor shield and solenoid control part togethers)

Step 15: Finish Frame Assembly

Finish frame assembly

Insert board I on the back (the one with holes)

Embed board A on the left side

Slot board E without forcing. If it stucks, make sure to run the Y motor wires at the back of the board E, to achieve this, just pull the wires a bit up from the inside of the electronics part.

Step 16: Mount X Stepper Motor

Mount the X stepper motor sideways to include the belt

To hide wires, the connector must be embedded in board A

Connect wires from the inside once the engine is in place.

Step 17: Mount Y Stepper Motor

Insert the bronze ring on B board

Insert 8mm metal rod

Add 8mm to 5mm connector

Add Y stepper motor

Tighten stepper and connector screws

Step 18: Load Arduino Sketch

Download

BraillePrinter.ino (file on bottom) or up-to-date version here

Adafruit motor lib

Step 19: Run the Braille Printer!

1. Connect USB to PC
2. Plug 12v power supply
3. Insert a A4 sheet (160g should be good)
4. Open Arduino Serial Monitor and type

{ abcdefghij# klmnopqrst#uvwxyz

• { : initialisation
• # : start a new line (because, on serial tool, return validate sending instead of including newline char)
• a..z : char convert to 6 dot braille

Rq1: The syntax should be updated in future version to include configuration

Rq2: This is a old video version (TODO: update it)

Comments

[basstone40]

Hi all!
I am very much interested to make this Braille printer for one of blind school in my region. can some one help me on the parts list since the links here are not available anymore! i need more info on the parts list.
Thank you so much!

[georgeluis2996]

Felicitaciones, excelente proyecto

[hussienfathysroor]

can you please send me which type of nema17 you use at this printer "17hs3401s or 17hs8401s"

[alanoud.ali.aldarmaki]

Hello, I loved the project so I'm working on it but I didn't know the measurements of the boards. Please I need help as soon as possible.
Thank you

[1609531012]

Not working properly it's printing horizontally and motor y is not rotating well the soloneid electronic part is also not working......... Plz help

[gabrielg133]

I build a model based on this but reusing an old printer, the arduino code works great, great project!
greetings from Argentina

[gabrielg133]

hi, what is the meaning of the chars of the string "fullAsciiToBraille" ?

[iapafoto]

The table give correspondance between ascii letters and the corresponding braille dots

Dots of braille symbol are coded as this :

1 8
2 16
4 32

exemple:
1 x 1 x 1 8
x x 2 x x x
x x x x x x

A is 1, B is 1+2 = 3, C is 1+8 = 9

fullAsciiToBraille differ from fullAsciiToBrailleAntoine on the way number are coded

[gabrielg133]

Is the end of the travel connected from pin 10 to ground or positive? And this program is made for only one or two?
thank you so much!

[iapafoto]

Hey Gabriel,

The end of travel is connected to the servo motor pins on "Adafruit Motor shield" as indicated in picture at step13. I gess it correspond to pin 10 and ground in Arduino shield.

Notice that for my Picoreuse, I put the end connector to left side but this is quite stupid so I modified the laser cut to unable others builders to put it on the right side or on both sides. However the Arduino code is still for left side so you may have to change it to feet your case.
If you want to use both side end of travels, you may use Pin 9 and ground for the new one (and change the Arduino code to use it).

[SalatielS]

Really nice project!
I've built one of those but I have a problem. The "y" motor does not move correctly, the steps are very short, so, the paper doesn´t move. Which parameter do I have to change to make big stepps?
TY!

[iapafoto]

Thanks SalatielS,

Line 47 of BraillePrinter.ino :
double MOTOR_SCALE_Y = 8; // step to mm

But this is quite strange

[SalatielS]

I've got really good news.

The problem was the L293D shield, it was factory damaged and couldn't controll the motor well. I decided to change that shield and after that It worked perfectly and I didn't needed to change any parameter.

Thanks for answering my question.

I attach a picture.

The text written is: "prueba".

[r4fa3l.mendes508]

Hi ,I'm building one based on your model. i have everything working except of the solenoid id doent seem to work,i´ve cheked and all the eletronics are correct but it doest move , any tip? thank you =), cool project btw

[iapafoto]

To test the solenoid alone you could use :
testSolenoid.ino available in
(int PIN_SOLENOID = 2; in the file)
https://github.com/iapafoto/BraillePrinter/tree/ma...

[iapafoto]

Hi! I had the same problem at the very beginning, the screws at the back of the solenoid brake the movement. Solution: add washers so that the screw does not block the solenoid!

[IvanokM]

Nice project. I'm building one based on your model. Do you need 2 end-of-travel switch? how do you connect them and where?

[iapafoto]

Good question! In fact there is room to put 2 end-of-travel switchs, which is certainly the best.
But in the one I built I only use one (on the left side, which is a bit stupid). I have corrected the design but not sure for the Arduino sketch. I could help you correct it if you need.

[IvanokM]

Oh that would be great. I made my embosser with 2 end-of-travel connected to the same pin. But I really need the arduino sketch. Thank you

[iapafoto]

I will watch. Problem, I do not have any machine to test right now!