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Week15. Mechanical design
group assignment
- design a machine that includes mechanism+actuation+automation
- build the mechanical parts and operate it manually
- document the group project and your individual contribution
* my role :
- 1. Electric and electronics schematic design
- 2. design Mechanical joints and links for grabbing and rotation of spring band
1.Schematic design
This is a basic concept block diagram for controll of bending machine.
First of all, our team decided about multi motor controlled machine so I found 'RAMPS ver-1.4 3D Printer driver'
and 'A4988' step motor drivers for each axis. It needs a high current power source at least 2A for each motors.
Basically estimate about 8A over currents, plus more power consumptions sums up to 12.5A 12Vdc SMPS
which was similar to our needs.Block diagram
Here are our main parts
No. Name Model infomation Quantity 1 MotorController RAMPS 1.4 3D printer Controller 1 2 MotorDriver A4988 4 3 PowerSupply SMPS DC12V 12.5A(model.NES-150-12) 1 4 LCD 20x4 Character type (i2c driver) 1 5 MCU board ArduinoMEGA 2560 R3 Compatible 1 6 KeyPad TTP229 4x4 capacitive touch switchies (i2c mode) 1
2.Mechanical design
In general bending machine got the spring role to extract an item.
I just thought about mechanism of the spring rolling process.
if motor rotate to clockwise it makes output an item and move anticlockwise
to go inside
Some bending machine has a spring just a linear wire to insert in through the central hole.
I design the shaft to hold spring with this style.
Also several units of spring makes a matrix(in our case 2 by 2 ), so add design
about gear sets for push-hold-rotate to spring.
As we can see the above assemble structure, we use a ball bearing to insert between
a spring joint shaft gear to a spring joint shaft. here are the stl format files.
1. motor shaft gear
2. spring joint shaft gear
3. spring joint shaft
1.motor shaft gear==> 2. spring joint shaft gear ==> 3. spring joint shaft
