Day 5
Shopbot

Notes:
Designing for milling
Due to tool radius inner corner of a hole or a pocket cant be sharp. Overmilling is advised in such cases.
Good design guidelines for milling.
http://blog.inventables.com/2014/06/learn-about-milling-inside-corner.html
http://www.efunda.com/processes/machining/mill_design.cfm
Better to use antimony to design material to be milled.
Dia max to be used for milling in shopbot- 6mm
Dia max to be used for milling in roland -3mm.

Assignment:
Slot comb to check pressfit combination.
When trying to pressfit object using jig saw kind of a configuration it is often required for us to experiment on different clearances that need to be employed in the design. I'll try to create a comb like structure having a slots of various thicknesses varying from the actual thickness of material to its thickness -0.4,-.2,+0.2 and +0.4. When tried to pressfit against thae actual material we get to know which fits good enough for our purpose. I'll try to use antimony to create the file and I'll try to make it parameterised, meaning that while changing some input values such as clearances and thickness I should be able to generate a comb structure for that specific values.


Design
On paper

Antimony



Output:
A png file generated from antimony for a sheet of thickness 4mm that can be used to create gcode in shopbot or cut in laser.

Product
  Yet to cut in shopbot or laser and needs testing.

Conclusion:
Needs to be tested yet.
Download the files at
https://www.dropbox.com/s/gyzuonwyzcti7bu/4mmPC.png?dl=0
https://www.dropbox.com/s/6sya7nwmlw8y75r/comb2.sb?dl=0

Side note
Shopbot:
Me with Francisco tried check if the shoptbot was setup alright. We discovered that the shopbot wasnt stopping at the limit switch and the software was buggy and crashing with few repeated clicks on the jog buttons sometimes.
I want to change the units of the shopbot from inches to mm since we are used to the cm and mm units in India better.
Shopbot was having a huge jerk when stopping during a jog move. This too I wanted to change for a long time.
Update: Luciano helped out on this and now the units having been changed to mm. The speed and ramp settings having corrected for smooth functioning. Only thing pending is making the limit switches work. I will have to go through the shopbot manual or the shopbot editor setting and play around with it.

Preparing Laptops and Lab Computers

Since fabacademy philosophy roots in opensourcing it only makes sense that Ubuntu and the free softwares are used. This allows free and ope access to anything and everything that is done in fablab. It allows repetability and a common framework that anyone can work with. One of most important of them is the OS itself which is the linux based UBUNTU system. The next most inportant software is  the fab modules which can control alomst any CNC machine that is present in fablab.

The pain of Ubuntu 

Ubuntu means 

"A quality that included the essential human virtue; compassion and humanity. there is a need for understanding not vengance, ubuntu is not victimization"

Indeed you need to have a all these to go through Ubuntu install and setup.

Creating digital accounts

During fabcademy you will be evaluated through your documentation which explains the world and the remote mentor or Neil what you have done. There will be times when your projects will be recommended by your remote mentor to higher faculty or Neil. They will see your website or the files you created. For these reason you need to learn to effectively express your work in a document. They should be online and freely available to anyone, they are opensource.

Day 4 week 1

Lab maintenance and Material handling

I took charge of Vinyl cutter and Roland Modela

I learned how to better handle the vinyl rolls. The vinyl rolls when kept vertically deform and get damaged at the edge which happens due to it not being able to support its own load properly. The correct way to keep a vinyl material is horizontal and the rolls to be taped at the open edge after use so that they don’t become loose.

The vinyl rolls were kept on the ground earlier.

Vinyl cutting

Used to make sticker and best use is to make PCB that are flexible. Can cut copper, epoxy and vinyl sheets.

Loading the material 

Use this lever to release or secure the vinyl.

Materials should be between the two translucent patches as shown in the picture. These have rough surface in order to grip the papaer better. The wheels should secure the paper when the lever is engaged.

Day 2 w2

Laser in our fablab is a trotec speedy 100 with that we have an atmos exhaust filter from trotec. Here's the laser machine and our super cool prefab guide and fabguru Francisco explaining about the filter system.

Polycarbonate lid and Atmos Exhaust Filter system

Filter parameters

Things to watch out for

Exhaust filter should be on.

Molding Casting and Roland Modela

The basic idea for this session is to create an 3D object through computer and try to make it in machinable wax in such a way that a molding pattern is created directly from it. Roland modela will machine the wax. We will try to replicate this object by creating a silicone mold and later use the silicone mold to cast hard plastic into it.

Day 5

Shopbot

Notes:

Designing for milling

Due to tool radius inner corner of a hole or a pocket cant be sharp. Overmilling is advised in such cases.

Good design guidelines for milling.

http://blog.inventables.com/2014/06/learn-about-milling-inside-corner.html

http://www.efunda.com/processes/machining/mill_design.cfm

Better to use antimony to design material to be milled.

Dia max to be used for milling in shopbot- 6mm

Dia max to be used for milling in roland -3mm.

Week 3 Day 1

This week we move to electronics design and fabrication.

Today we started with electronics production. The goal was to fabricate a pcb from an already existing design. We use roland modela to fabricate the PCB.

Assignment: to fabricate a version of fabISP using Roland modela and fab modules.

Process

We downloaded the the following designs.

Week 3 Day2

Many of the fabacademy cad items are design that have .cad extension. These were designed in kokopelli. .cad file is basically a python script. Today we try to edit and understand how the script ad kokopelli.

Assignment

We add components to a hello.ftdi.44.cad and wires on a board and fabricate it.

Consider the following methods of programing a microcontroller

Arduino ide- most user-friendly, many tools, quick,  easy

C  - intermediate difficult, need to have more hardware knowledge, more efficient in code handling and storing, more freedom to program.

Assembly lowest level of programing, need to have through understanding of the hardware also, more difficult, highly efficient in code handling and occupies least storage, and allows most freedom to program.
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