Week eight: Computer-Controlled Machining

Individual assignment

The assignment for this week is "create something big", so i had to design, fabricate and assemble parts.

Tests

Before designing my furniture, I decided to do some tests, because I will assemble by insert and I need to know if I should give some tolerance so that the pieces fit or not, besides other considerations that I should take into account.

First, I decided to design some small inserts, the milling cutter we have is 3/16 ", which in mm is approximately 4.8, when making the inserts, the cutter would not have anywhere to go in the corners, so I included the dogbones in the design, with a diameter of 5mm so that the cutter can pass without disturbing the design

Piece1. I designed the piece to work on 9mm MDF, the depth of the insert depends on the thickness of the material

Piece2

Then, I exported the face of my solid as dxf, to send it to the multicam program, more information about the machine below

I open the program with which the multicam 3000 works which is enroute and I import my dxf files, I manually order them and I select the operation that I want to do next to the parameters, I will do 2 operations, because one piece has holes to fit, so to this operation will be called female milling, while to the outer edges a male milling. We have the following parameters in passes:
Number of passes: 3
Maximum per pass: 12.7mm
Per current step: 3.9mm
Depth of final step: 2 mm

For power and speeds we have the following parameters:
Feed speed: 300 mm / min
Final step feed: 300 mm / min
Penetration speed: 180 mm / min
Delay: 0
Shaft: 18000 rpm

Same parameters for both operations

First we must do the female milling, here you can see the code g and the operation

Then the male milling

This is the result, to see how the machine operates, calibrate and the epps that should be used see the individual assignment below

It is possible to assemble well without leaving, I needed the support of a small hammer

Corner assembly with the same parts

Internal fittings

In conclusion, if I work with MDF it is not necessary to design with tolerances, since the result is quite good, but it requires some hammering to make it accurate, in addition the dogbones must be taken into account.

Design

I wanted to create a desk and bed combination, because i saw a furniture designed and made by the architect Roberto Droste with a nice mechanism, with this idea i decided to made something similar. I used SolidWorks to design the pieces and assembly to see if it will works.

I used a 3/16" End mill, approximately 4.8 millimeters, so i included circles of that size to let pass the mill.

I wanted to be sure that the pieces of 12mm of thickness can be assembled, so i used "Assemby" of Solidworks to test.

The case

The bed

I needed to export as .dxf because the software CAM of the CNC router works with this extension and .dwg

Fabrication

In our fablab we use Multicam 3000 series CNC router, you can find the specs in this link

Before entering to the area, i must wear the personal protective equipment (PPE)

Steel toe and electrical insulating boots

Woodworking gloves

Earmuffs

Protective eyewear

Then, i turned on the multicam

And the air valve

Then, i put the MDF board of 12 mm on the plate of CNC

And measured the width and length

Turned on the extractor of the plate and start the calibration

First, X and Y axis

Then Z axis with this tool

Connect the tool

And calibrate

Then, i imported my dxf files using the software of the CNC and i acommodate the pieces of the furniture manually, taking on consider the measurement of the bed and the pieces, cause i didn't use a nesting software.
Then i set Parameters in passes:
Number of passes: 3
Maximum per pass: 12.7mm
Per current step: 5.15mm
Depth of final step: 2.5 mm

Feed speed: 400 mm / min
Final step feed: 300 mm / min
Penetration speed: 120 mm / min
Delay: 0
Shaft: 18000 rpm

And export as G-code to JobConsole, and start machining!

Assembly

Remove the pieces

With the respirator face mask i removed the small particles using this tool

And start the assembly

Mark the pivot point

Almost finished

Desk finished

Bed

Hero shot!

Download files

Bed base
Bed side 1
Bed side 2
Desk base
Bed base
Furniture base
Furniture top1
Furniture top2
Furniture bot
Furniture support
Bed assembly
Furniture assembly
Piece for pivot point
Test Piece 1
Test Piece 1 dxf
Test Piece 2
Test Piece 2 dxf
Furniture dxf1
Furniture dxf2
Furniture dxf3