Week Five : Electronics Production

Already I have explained my Engineering background was Mechanical, So I dont have a good knowledge on Electrical Electronics. So I was excited this week to learn new technology.

Our instructor Vinod has given a wonderful session on the basic Electrical and Electronics.

Yadu also given a great idea on milling machine.He also gave an idea how to use tool bit without wear and tear.

Characterizing the specification of our PCB production process

while characterizing we found that our milling tool bit is only able to mark trace upto 0.20, It doesnt have the accuracy to mill the thickness of 0.001 and 0.01.

`Software : Offline FabModules`
`Input Format : Image(.png)`
`Output Pocess : Roland mill(.rml)`
`Select Tool : PCB(1/64) - for Milling`
`Select Tool : PCB(1/32) - for Cutting`
`Set Axis : Set X, Y & Z`
`Select Machine : MDX-20`
`Calculate`
`Sending : Send`

Found out that machine is not able to make trace of thickness "0.01" and "0.001" due to wear and tear of tool bit and aging of machine

Making an Circuit Programmer

I chose Brian's website for making an in circuit programmer

Milling Machine

Milling machine is used to machine flat surface.Here we used to mill tracks and cut the PCB(Printed Circuit Board).There are single side PCB's,double sided PCB's as well as multi layered PCB's available.

In single side PCB's we have a copper layer above a substrate of non conducting layer.In double sided PCB's we have two layers of copper at top and bottom of the substrate whereas in multi layered PCB's we have alternating layers of copper between substate layers

Machine we are using is Roland Modella MDX-20

Tools used in Milling Machine

We use two types of tool in milling machine for milling tracks and cutting process.

Tools used are shown in image below.

`(1/64) - for Milling`
`(1/32) - for Cutting`

Fixing the copper board on the table

`Double sided tape is applied to the copper board and set the board on the bed`

Software used in Milling Machine- MDX-20

`Software : Offline FabModules`

Setting X,Y& Z axis in Milling Machine- MDX-20

`First set the tool and give the cordinates for X,Y & Z in FABMODULES and move`
`Then adjust the tool so that tool touches the bed and Calculate and Send`

Setting Tool to Zero- MDX-20

Now going to the Rolland Modella MDX-20, there is a bed to keep the PCB for machining. Before starting it is really important to have the bed levelled, Even a 1mm level difference is a huge difference when it comes to milling the PCBs, it will result in broken endmills or uneven PCB surface. The bed should be flat and steady to make the right cut on the copper surface. So our Instructor took of the bed and cleaned its surface, he set up the bed

While sticking the PCB to the board, we should make sure that there are no air bubbles or dirt, otherwise it could affect the depths of the cut

Fixing the tool bit to the tool head , allen-key is used to tighten and loosen the tool from the tool head. And we should make sure that the tool is fixed properly, otherwise it would broke the tool during machining. The tool must be tightened slowly and alternatly on both sides so that it ends at the center and the length of the tool to the cutting surface should be half or less than half to avoid vibration of the tool

The machine bed has to be first inspected for any bends and deformations. If any bends are observed, the copper blanks should be mounted away from the deformed areas. If the blanks are mounted on an uneven surface, the depth of milling and cutting will vary across different areas and can result in an improper operation

`First I have pressed the view button on the machine.The plate will come front and the head will move to right`
`Load the 1/64 inch bit to the head,Put a sponge above the bed inorder to save the tool tip from breaking during the tighting process`
`Use the allen Key to tighten the tool bit in head`
`Now press the view button again to move to (0,0)position `
`Give the cordinates for X,Y & Z in FABMODULES and move the tool head using arrow key downwards towards material`
`Check the Z axis and adjust the tool bit using allen key,so that tool touches the PCB material for milling / cutting`
`After setting these X,Y & Z axis,load the png file to Mill / Cut and Calculate and then SEND`

Components Used for making my ISP

`Microcontroller - ATtiny45`
`Resistor R1 & R6 - 1 Kilo-Ohm`
`Resistor R2 & R5 - 499 Ohm`
`Resistor R3 & R4 - 49 Ohm`
`Zener Diode 3.3V`
`ISP - 2*3 PinHeader`
`Capacitor - 100nF`
`LEDs - Red & Green`
`Switch`

Design for Milling and Cutting

`Software : Offline FabModules`
`Input Format : Image(.png)`
`Output Pocess : Roland mill(.rml)`
`Select Tool : PCB(1/64) - for Milling`
`Set Axis : Set X, Y & Z`
`Select Machine : MDX-20`
`Calculate`
`Sending : Send`

`Software : Offline FabModules`
`Input Format : Image(.png)`
`Output Pocess : Roland mill(.rml)`
`Select Tool : PCB(1/32) - for Cutting`
`Set Axis : Set X, Y & Z`
`Select Machine : MDX-20`
`Calculate`
`Sending : Send`

Steps include in Flashing process

1. Install Compiler for Debugging

` sudo apt install gcc-avr`

2. Install Library for Compiler

` sudo apt install avr-libc`

3. Install flash to convert hex file to chip

` sudo apt install avrdude`

4. Install all functions to store in file

` sudo apt install make`

OR we can run on single command as shown below

` sudo apt install gcc-avr avr-libc avrdude make`

EDIT PROGRAMMER ?= "usbtiny"

Dowload Firmware and Open Terminal from inside firmware folder

1. Converts elf to .hex file

` make flash`

2. Fuse certain functions

` make fuses`

3. Search whether USB has listed

` lsusb`

4. Disable the RESET function

` make rstdisbl`

5. Confirm the USB listing

` lsusb`