Assignments
Group Assignments
- Do your lab's safety training test runout, alignment, fixturing, speeds, feeds, materials, and toolpaths for your machine
Individual Assignment
- make (design+mill+assemble) something big (~meter-scale) extra credit: don't use fasteners or glue
extra credit: include curved surfaces
GROUP ASSIGNMENT
More specific detailed from the worked done with Ernesto Castro in Fab Lab Universidad de Lima here
Fab Lab Ulima s a f e t y t r a i n i n g
3000 series Multicam Router CNC.
The machine we have at Fab lab Ulima is the 3000 series Multicam Router CNC for an area of 2040mmx1200mm. I hve never used this machine. The instructor and the machine worker give me the first steps and security steps to start. First I was gave a lab coat, safety earmuffs, gloves, glasses and I had to wear safety shoes with steel tip, and I use my construction boots that has them.
To start the machine I had to identify its parts. Where to turn on, the air suction, where are the mills and where is the command control.
The machine works with EnROute Software Where to select the mill, passes and cuts for the machine.
Tests t o l e r a n c e s and dog-bones tangents
My part of the group testing was to test tolerances. I did some joitns for my individual proyct, also texting how it cuts curves. I tried to make some dog bones different by the tangent of the 6.2mm circle for the mill of 6mm. The best one was the 19.5mm for plywood of 19mm. It was safe to joint and not forced. So I choose to make my individual project in this material.
S P O I L E R a l e r t
Plywood of 19mm is TOO HEAVY. Everything connected, however with two pieces it starts to be so heavy and the joints are so precise that it involves applying force to some parts to fit them together. It also involves twisting the entire structure to secure it at the bottom and then at the top.
INDIVIDUAL ASSIGNMENT
For the "make something big" assignment I wanted to do furniture. As an architect I have always liked when furniture is a piece of statement in a space. And that is why I thought about the coffe table in my living room. How can I incorporate the love for nature of both my mom and I with a piece that focus the living room?. It was the perfect idea! And also to experiment with parametric design and joints to maybe have different versions of the idea.
nature coffee t a b l e
F i r s t I D e a
sketches
Following the drawings in my cyanotypes I wanted to make a coffe table that came from nature curves of a tree and focus on the plants pots. Also I didnt want the typical 4 points of support in the ground. And I wanted the typical table to be like levitating.
Initial sketch of the table in plan and elevation.
Parametric design
I made some first curves in Rhinoceros as I wanted the limits of the table to look like. I draw this lines first in parallel view in front, top, rigt, left and back view. So I could control each view of the table.
I did not wanted the supports of the table to be in each corner as it could be in every table. I first did the elvation curves I imagine for each side and the loft the curves in rhino to see the natural curve of each elevation while joining in one polysurface.
The volume left by the loft the curves in rhino.
I liked how the loft made a natural 2 supports for the whole table. The challenge was to center the weight in just this 2 supports. So to think about the the structure I choose a waffle structure in grasshopper because I can manage this weigh easier. I made it with bowerbird plugin I download from here. I used grasshopper to make the structure and not itself in Rhino to have the option of changing the joints space and material thickness.
Bowerbird waffle structure process
Why Waffle structure?
To avoid extra joints and make each piece itself to be the joint. Also, to play with the dimensions of the acrylic or glass table and the placement of the flowerpots, since if there are also flowerpots at the base, the upper base of the acrylic could open up to them, leaving a gap so they naturally extend over the table.
Result idea after the bowerbird organization of the pieces and joints.
To organise the pieces and find the correct order to set everything up I did the nesting in grasshopper in an area of 2.40 x 1.20 m that is the area of the plywood. I used OPEN NEST plugin in Grasshopper to help me organice the alredy pieces I had. For this I worked with the result curves and projected them in order to then organice in a sheet size of the material I mentioned. After that with each center project text in each piece.
Nesting process
How to make the dog bones
To make the dogbones in the nesting I tried importing it in Fusion, however I couldn't make it there I think because of the lots of curves of the forms. However I found a way to make the dog bones in rhino with a phyton script I download from a rhino forum here. I also found a rhino plugin that makes the same but i cound't make it work. It is listed here.
Dog bone script in rhino
From recommendation of my instructors I gave a diameter of 6.2mm for a 6mm mill since it has to have a minimun tolerance. Also de joints for 19mm plywood are made with 19.5mm as in the group test it fit perfectly with not much pressure.
f a b r i c a t i o n P r o c e s s
Routing the g code for fabrication
place components
connect components
name and connect components
name and connect components
name and connect components
Setting EnRoute.
Cutting the pieces in the CNC machine
NESTING result ready for fabrication.
G code
Cutting pieces
Taking out the pieces
assembly process
structure upside down
Table in my living room
Table in my living room
Test 1 : result
Original form and change while making
From the idea to the result it is upside down. The initial idea was that only the two edges would support the acrylic as a conventional table but an organic base. However, when assembling it, two things happened. Gravity got the better of me, and it was easier to assemble it upside down. And also the supports where not doing their job and could not stabilize the table. The wight in one side make it imposible to stand.
top view and plants positioning
new pieces for the base support
