Fab Academy 2015 - Name Surname

basic pressfit processs

see kerf test later.
3mm cardboard is used and in this case a 0.2 mm kerf is added

press fit parametric process

generating a waffle for the spatial construction of a figure with volume by flat pieces

As indicated in the fab academy assessment guide I approached with a model close to a possible final project

Following with the work direction oriented to the construction of the pantheon, an algorithm that reproduces the space in parametric terms (dependent on factors) that are simulated for now is approached. the chosen software is grasshopper, both for being a rhino pluggin and the ease (for compatibility with the rest of the work) with which all other processes can be developed. Grasshopper is, on the other hand, the most extended free access parametric software, having at our reach infinite solutions and libraries. to begin we build one of the volumes already devised.

we reproduce the same process by varying factors, in a composition that conforms to the original model, and we adopt the brep type in principle for the volume.

only adding the third piece and group for easy handle.

in the next steps different operations to transform brep type in mesh both to foresee possible problems in the conjuncion of vertices when the three solids are joined by the application of the pluggin of grasshopper that comes next.

the idea is to reproduce the solid set in waffle mode, that is, as a union of intersecting planes using pressfit that adjusts to the desired volumetris. for this the manual process is the following: 1- form parallel planes in the direction x that intersect the solid 2.- do the same in the direction and 3.- give thickness to the planes using type brep 4. find the intersection of all the planes now converted into volume. 5.- from the midpoint of the intersection move a distance as depth of intersection 6.- find the new intersection 7. calculate some slack according to the characteristics of the material.

To simplify things use the Bowebird plug-in accessible and free at food4rhino. this plugguin also allows you to unfold the desired sections in a plan and prepare them for cutting, adding labels to each piece, without which it would be impossible to assemble them.

In the case that the distribution of cutting planes does not conform to the solid we wish to build, we can add, or replace manually constructed plans, in the desired orientation and position..

the result of the grasshopper process is two pieces of type brep only juxtaposed. and the result of the waffle opperations is a flat distribution of the parts to be cut properly labeled, after which you only have to toast them in rhino in the layers with necessary colors according to the characteristics of each lasser

an image that is not very useful, but illustrative of the process, with the cutting planes converted into sections, and the distribution of flat curves ready for cutting.

once roasted in rhino the whole algorithm becomes a vectorial file, perfectly manipulated as if we had drawn it. This is distributed in layers according to the formatted instructions for cutting the machine. in this case blue for cutting, red for engraving etiuetas and magenta only as indication of size of cut without effects in the laser cut.

lasser cutting

Characterize your lasercutter, making lasercutter test part(s), making test part(s) that vary cutting settings and dimensions.

first I try the spirit gls
láser font 30 a 100 W (10,6 μm) / 20 & 60 W (9,3 μm)
work Área 810 x 610 mm ( 965 x 610 mm)
max size 1.016 x ∞ x 177 mm
table 1.025 x 705 mm
engine speed 2.032 mm / seg
Resolution (DPI) 125, 250, 300, 380, 500, 600, 760, 1.000, 1.500
Lens focal 2”, plus 1,5”- 4”
Vol 220V AC
Memory 32 MB stándar
Seafe Clase III
Pw 2.000 W - 4.400 W

there is two basic ways to use the lasercut : RASTER ENGRAVING and VECTOR CUTTING

UPDATE : engraving and cutting parameters

There is possible too adjust the power / speed settings or simply adjust the contrast of the image in software

DITHERING : This option controls the way a raster-engraved image is processed. The “digital image to engraved output” process can be processed via two methods: Dithering or Error Diffusion. Each offer additional output options yielding different output effects, style, and quality.

UPDATE vector cutting

most common for cutting and build

in the spirit you will need to set your design fill color to white and set its outline thickness between 0.001" (0.025mm) to 0.004" (0.1mm)

suggested parameters:

..for acrylic and wood power 100% and speed 30%

.. general parameters recomended using in fab for cardboard

..cutting : power 50% ( cut) // speed 30%

..mark and bend : power 30%// speed 90%

..engraving : power 20% // speed 30%

RECOMENDED MATERIALS

Plywood/Composite woods wood, MDF , Acrylic,Lucite,Plexiglas,PMMA Paper,carton Cardboard, Cork Polyimide Mylar Depron foam Teflon natural fibers : Cloth,felt,hemp,cotton Leather, NON-CHLORINE-containing rubber

NOT RECOMENDED MATERIALS:

PVC (Poly Vinyl Chloride),vinyl,pleather,artificial leather,PolyStyrene Foam,Fiberglass, ,Polycarbonate/Lexan, ABS,PolyPropylene Foam, HDPE,Carbon Fiber

process (testing)

The machine has security controls of stop and open door, a control panel, and a USB port. as an external element, a blower coater and a suction motor associated with a filter with separate switches.

the controller has a small memory that keeps files in queue while it is on. On the control panel you can modify the power and speed, as well as the height to focus (although it has autofocus) and a menu to access the files in queue

the drivers of the machine do not include our own software, so we configure the cut by layers in autocad, assigning a different speed and intensity, we want to cut or only burn superficially

in this test the layer configuration that provides power and speed per layer was made according to the previous tests for the same thickness of cardboard, but for some reason the laser was out of focus (probably due to some curvature of the cardboard), so the distance from laser to carton varied. the result is that the cut is not complete and does not completely cut the cardboard.

the problem is solved by increasing the power since I can not find a way to recover the flatness of the material in the bed of the machine.

the drivers offer the possibility to record in raster or vector mode. in this test we use a type of letter with edge of line with the intention of not burning in raster mode but vectorial (and in its case cut) the edges of the letters. since the configuration of layers of the arcivo did not change, the edges were not cut and the letters were not outlined. It is a clear failure, it is considered good and we continue.

with this we do a test on a dxf file imported in autocad but produced in the waffle rhino that we finally want to build. two fundamental problems the file is not imported in the appropriate scale, so the projected spacings in the pieces are insufficient due to the thickness of the material. On the other hand, the curvature of the cardboard again prevents a complete cut. the machine has autofocus, but its data collection is not on the entire surface, ie how much the material is perfectly flat

Solved the problem with great risk because we repeat the cut without moving the cardboard at a slower speed. the cut is completed with some minimal defectsh a rhino function.

autocad is an uncomfortable and obnoxious complex old software, but I can not get the machine running from rhino. so I am forced to import dxf generated in rhino with a lot of compatibility problems. I discover later that maybe it is due to the versions. A nightmare. waste of useless time. getting to match the thickness of the material with the slots of the pieces we cut pieces of the waffle in its first conformation (with errors).

defective cutting detail due to lack of power in the cutting layer. Faults in the depth of cut by the thickness of the material. we recalibrated the intensity

first attempts to cut waffle pieces with 4.5 mm cardboard. enough cutting defects.
it would lack some slack by modifying the cutting widths so that the fit of the pieces was perfect (see tests of thresholds and slack)

comparison of size between the first pieces of court (without kerf) and the second ones to larger size (with kerf though insufficient)

UPDATE : kerf testing

for the kerf check I make a simple test figure with 3 mm cardboard.

so I consider an initial slot with 0.3 mm kerf, 3mm - 2 x (0.3mm) = 2.4mm

however due to the considerations of the material, due to its flexibility and the possibility of crushing in the joints experiment with a slightly larger dimension

cutting of test modules with 3 mm carton and slot width cuts of 3.1 mm 3.3 mm and 3.5 mm.

The result in the fit of the pieces is to confirm the discomfort and sometimes impossible to fit when there is no kerf, despite the flexibility of the material.
KERF of 0.1 mm the fit is still costly facilitated by the flexibility of the material and very inefficient in the assembly of small parts, or when the sections are very abundant.
KERF of 0.3 mm the behavior is perfect, allowing, with some slackness, an easy assembly in small and very abundant pieces
KERF of 0.5 mm is excessive and produces excesive movement in the parts after being assembled.

Modelled experimental objects/part of a possible project in 2D and 3D software

once decided a kerf of 3.3mm I use the waffle previously designed to approach the figure of the pantheon as an idea of the final project and cut the pieces for assembly

different phases in the progression of the waffle assembly. it is recommended to first mount the U0 and V0 labels and continue riding in parallel directions and then complete it with its perpendicular direction.

different tests for the crazed assembly of the different pieces without the order of the waffle, its good assembly is verified and originates an enormous variety of spaces from what we could call a good tool for the formation of conceptual models of spaces on which it would be interesting to work.

vinyl cut first

UPDATE CUT PARAMETERS

force/press: between 100 and 130.
Speed: Depending on the complexity of the design you want to send to work. It depends on the size of your most pronounced characters or contour
THE FORCE / PRESS, is the force exerted by the cutter towards the material, therefore if we increase the Force value, the knife will crack the material with more pressure.
The idea is to find the maximum value of the Force, which sufficiently cracks the material, but that does not transfer / cut the protection occupied by the Vinyl or Thermo transferable vinyl among others.
The Force value is different to use in each material, since it will depend on the width or thickness of it.

The Speed / Cut Speed, is how fast the Plotter's car will move, to do some work.
Now this parameter is important, since it must be adjusted to the size of the design to be cut and its complexity.
Therefore, if you need better definition in certain areas, you must adjust the Speed parameter, in the following it indicates which Speed values, use depending on the size of the fonts.
font size < 10 speed 10 to 20
font size 10 -30 speed 30
font size 50 - 500 speed 60
font size over 500 speed 80

vinyl cut second

UPDATE : SECOND CUT DEFECTS AND PROBLEMS

This second cut is made with the same parameters, same conditions as the first. I had to repeat it only because the previous one was made in the facilities of the Higher Technical School of Architecture of Madrid. when repeating the same work in the fab lab of the IED madrid at this time and according to the managers there was no vinyl available. however I found a scrap with which I could carry out the work in its term. This scrap had a limited size and many wrinkles, which caused cutting defects to cause the blade to not always cut on a flat surface. On the other hand, according to the instructions of the people in charge, the blade was not well aligned or sharp enough due to its wear and tear. This motivated the repetition of the work already out of term by recommendation of my local evaluator.

vinyl cut third

In order to ensure a clear vinyl cutting process, I repeat the operation for the third time this time with a simpler logo

for that I created the logo in Rhino and from there I export the curves to Adobe Illustrator filling them with a plot

I introduce the vinyl and adjust the rollers as in the previous processes

in the rest of the process I made several tests adjusting the cutting pressure. in this with value 300 gr the blade cuts the paper of shelter also and even starts a little of the vinyl

in this with value 240 gr the blade cuts the logo cleanly, although still very deep lifting the paper

in this one with value 100 gr the blade cuts the logo cleanly, leaving intact the paper of protection and allowing the extraction of the logo easily