Ex. 05 (1:1 Prototyping)

img_8073

Limit Switch Fusion 360 File

Pen Holder Fusion 360 File

This page is dedicated to prototyping parts at a 1:1 scale for various projects.

The implementation of the 1-axis gantry with the vinyl cutter attempted last week was a mishmash of semi-sophisticated computational processes and crude assembly strategies. For our first round of prototyping, we opted to produce specialized components designed to eliminate some of the more “jank” elements from the original scene. Specifically, rather than binding a writing utensil to the carriage a la orange tape mummification, we began sketching a simple pen holder that would anchor the utensil to the carriage, allow for variable diameters of the utensil, and alleviate some of the pressure put on the utensil by the paper it makes contact with:

Initial Sketch of the spring mechanism.

(I’ll be blunt, we have no idea what the hell this thing is called. It sounds like “Flection”, we think, but for now I’m referring to it as a “spring”.)

img_8062
Basic functionality detailed. img_8063
Plan / Elevation / Section Sketches. This is where it began to resemble our initial prototype. img_8064
Some harebrained implementation strategy ideas. Stick with me here, these may be important… img_8068

We set out into the wild west of Autodesk Fusion360 with our heads held high, and based on sketches, began mocking up a prototype for the pen holder. our initial printed prototype featured some critical dimension errors, so we stopped the file midway (ain’t nobody got time for that!), but the print made it far enough for us to test our spring, and it worked beautifully, until it broke under mysterious circumstances (which is what we’re calling Grey now.):

Chamber which holds the sheath for the writing utensil. Started here and worked my way up. pen-holder-3000-v1-01
The implementation of the spring. Can’t freakin’ believe that this worked… pen-holder-3000-v1-02
In the complete picture, you get a better idea of how the set screws work. Basically, in order to minimize the spring’s propensity to bend in undesirable directions, we can place two screws on either side, and use the pen on the front face as braces. This way, ideally, the spring contracts in 1 axis only: The one we want. pen-holder-3000-v1-03
Our beautiful print (V01) … Specifically, the sheath for the pen was significantly undersized. But again, very satisfying to see that the spring actually did its job. img_8069

For the second round, we went with significantly beefier top/bottom chamber pieces, which, thanks to my ingenious implementation of global variables in the fusion workflow, meant that the proportions for almost everything adjusted accordingly. That is excepting the spring, which was, as far as parametric definitions go, a total failure in my eyes.

We talked a bit in the previous class about some fundamental principles of parametricism, specifically the fact that the success of a parametric model relies more on evolving relationships between entities than it does on the oft-mentioned parameters (i.e. sliders/domains) themselves. relative (lol) to grasshopper, Fusion absolutely seems to promote these relationships heavily. My issue with this arose when making the spring. I set it up as I would a similar form in grasshopper – creating my field of construction geometry, which in this case was 2 rows of points, in order to divine pipe-able linework. However, my issue is that, where in grasshopper I would be referencing objects, lists, trees, etc, Fusion prioritizes actions, transformations, evolutions etc. The long and short of it is, when I updated my number of points, I realized that Fusion was not interested in recognizing them as a family, which prevented my linework from updating. Is this an inherent limitation of the software?

For last week’s iteration of this project, the collar that holds utensils on the vinyl cutter was occupied exclusively by our limit switch. Che-Wei suggested trying to place a writing utensil in the collar as well, so that the final drawing exhibits both the SVG path that generates the drawing, as well as the drawing itself. Grey hopped on that Fusion train and modeled a piece that supplements the collar with a writing utensil sheath of a more appropriate diameter for the utensils we intend to draw with (LE PEN), as well as a chamber for the limit switch holder that would make contact with the drawing surface without jeopardizing the linework coming from LE PEN.

After some sizing and resizing, The prototypes were bundled into a .gcode with Simplify3d and sent to Jules Winnfield (the studio printer).

Initial STL placement. Pen holder for our gantry is on the left, limit switch holder for the vinyl cutter is on the right. simplify-01 simplify-02
The final pieces. Printed with black Colorfabb NGEN, E3D Titan extruder, 230° Celsius Nozzle Temp, 70° Celsius bed temp with a coat of Aquanet hairspray and 12 skirt lines. img_8072 img_8073
 The pen holder, with fastening and set screws installed. However, the M5 bolts we planned for were a little too large after printing, so now all the bolts are actually M4s. Except! The Set Screw for the pen holder, which we designed at 5.5mm, and it snuggly fit an M6. img_8075 img_8076
 Installation on the carriage. Fit like a glove. img_8080 img_8081
 The limit switch holder, with endstop and pen attached!! img_8084 img_8083

The issue we’re dealing with now is Sure-Cuts-A-Lot’s cross to bear. SVGs we saved from last week would not initiate this week. What’s up with that?

 

Update – 09.26.2016

The pen holder is broken. Its connection pieces snapped off under too much pressure. solution? Reprint with larger connection cylinders to create a more forgiving distribution of pressure.

The Pen Holder. You can clearly see where the fasteners were removed. image1

¯\_(ツ)_/¯

 

Update – 10.06.2016

 

We’ve begun prototyping attachments for the magnet in our analog drawing machine (find that project in its entirety here. Namely, we’re trying for a sort of universal shovel; a cross between a UFO and a cow-catcher on the front of a steam engine:

 

section of the model. Technically it is upside down in this view, but we attempted to create a sort of backwards compatibility, that would allow the magnet to sit in the chamber on either the top or the bottom. we found that this orientation was more successful… constructionline_shovel
The final profile. The failures of this design are detailed more specifically in the page for ex. 07 finalfigure_shovel
The final design in sand. Printed with E3d Volcano, which makes no sense for an object this size, but you take what you can get. image1