Week 17- Machine design

Overview

For this week we have two assignments:

Group assignment

- Design a machine that includes mechanism + actuation + automation

- Build the mechanical parts and operate it manuall

- Actuate and automate your machine.

Individual assignment

- Document your individual contribution.

Have you?

Documented the machine building process to the group page.

Documented your individual contribution to this project on your own website.

Linked to the group page from your individual page as well as from group page to your individual pages.

The Process

This week is about how to manage to work as a part of a team and master the skills needed to collaborate with others. So we choose to have a little fun, yes we still in the panademic version of the academy but this is our last assignment so lets try to take it easy and make something happy =)

At the beginning we have a lot of ideas, but we decided to create an Egg Plotter, based on arduino, 2 stepper and 1 servo motors. In this page I will ONLY document my individual contributions within the team to create the machine, but the overall view about the machine and the tasks performed can be found in Our Super 2 Days Assignment.

the video and concept behind our idea.

My contribution

My contribution was in in the automation phase and in the integration part, in which I was responsible for:

Design the a motor drive pcb to interface 2 Nema-16 and servo motor with the Arduino
Assembly and test with Mans
Group Documentation with Row'a

The Steps:

1) Motor drive specifications and system analysis

Specifications (Electrical)

Minimum output drive capacity = 12V and 1A.
Input signal from any Microcontroller = 5V or 3.3V
Use 1 A4982 microstepping driver to operate bipolarsteppermotor Nema-16
Assume in all power calculation that copper layer is only “1 oz thickness”

Specifications (Mechanical)

Use 24-pin TSSOP with exposed thermal pad For A4982
Board dimensions 2.5*1.5cm with curved angels
Add heat sinks in pcb layer.

2) Block Design

3) Circuit Design

your number one friend through this step is the datasheet. so let's have a quick tour in A4982 datasheet

A4982 Specifications

output drive up to 35 V and ±2 A

3.3 and 5 V compatible logic supply

Thermal shutdown circuitry

No smoke no fire (NSNF) compliance

Circuit Components

1* A4982

2* 0.22uf ceramic capacitors C1,C5

2* .1uf ceramic capacitors C3,C4

1* 100uf electrolight capacitor C2

1* 5kohm resistor

1* 100kohm resistor Rs1=R5

1* 33.3kohm resistor Rs2=R4

1* 25kohm resistor Rosc

2* 8 Male-pinheader

circuit design from datasheet

Application Layout from datasheet

4) Schematic Design using Kicad

Download Fab-library:

you can find a fab-library with all the inventory component Here. download it then create a folder wherever you want for kicad folder to be kept.

open Eeschema go to Preferences-> Manage symbol libraries

I've notice that the main component of the circuit A4982 is missing from fab Fab-library
so I download digikey-kicad-library and following the same steps, yet I face tham same issue so I will need to deisgn the symbol library from scratch.

Choose add existing libraries to table. then navigate to your folder and choose fab.lib and click ok.

Page setup:
add the design information and the schematic Grid setting

Edit page setting.

view -> Grid setting.

Symbols:
add symbols to the sheet and create symbol if needed

I create a text file with the component then start to add it to the schematic.
along side that I open our flinc-inventory-sheet to make sure we have the same values of the components I need.
we don't have all the components that I need so I tweak the design a little and updated the text file.

Circuit Components

1* A4982

6* .1uf ceramic capacitors

1* 100uf electrolight capacitor

3* 5kohm resistor

1* 100kohm resistor

5* 10kohm resistor

2* 8 Male-pinheader

from Kicad I choose symbol editor then I create a new library called machineDesign and select the symbol properties to give our symbol it's identity

we go back to the data sheet to get the pinout assignment in order to create our A4982 symbol

Now we are done with all the circuit components

I choose U for reference designator as I'm going to deisgn an IC
please find this Reference designator-wikipedia as a reference

A4982 new symbol =)

add the A4982-Datasheet to our symbol

Arrange, Annotate, Associate:
arrange, annotate symbols and associate with footprints

Circuit Components final

1* A4982

6* .1uf ceramic capacitors

1* 5kohm resistor

1* 100kohm resistor

1* 10kohm resistor

4* 49.9kohm resistor

2* 8 Male-pinheader

From the datasheet I know the A4982 which is TSSOP24_6.1x7.8mm_P0.65mm.

arrange the components and group them by functioning, and I change the schematic components once again.

Wiring, Nets, Electrical Rules Check, Comments and Netlist generator:
final steps and edits to the schematic

Run ERC check.

generate Netlist.

when I run ERC check I have three erorr in the connections name some pin assignment conflict which it was easy to fix.

Generate the Netlsit is the final step after finishing all the design.
This step is really important in order to connect the schematic with PCBnew in which we will going to create the PCB layout.

Now it's time for the layout design.