3. Computer Aided design¶
Computer aided design,”CAD”. Something I have attempted unsucessfully in the past and shamefully gave up on. As a 3D printing teacher I became a master of thingiverse and Tinkercad. I wowed many a 12 year old with my stolen designs and rudementary browser based design skills. Alas… I cannot fool Mirriam. Nore would I dare try.
But now that I have acess to the knowlege a true designer posesses. I might posibly get over those humps that cause me to give up on CAD in the past. Who knows, I might even “git gud”. Well I dont actually have a choice.
This Week’s assignments: model (raster, vector, 2D, 3D, render, animate, simulate, …) a possible final project, compress your images and videos,
I have decied to go with Fusion 360. I have a minor degree of familiarity with fusion as I have used it in a few minor projects. It is a great free CAD program with some extra functionality such as CAM and some other things that could be used in other areas of making and in the broader aspect of the fab academy.
Research¶
Sooo, My final project idea doesn’t really require alot of 3D modelling and although an LED strip is a great opportunity to experiment with parametric design. However a LED strip does not a Final Project make.
…I must consult the Oracle.
With her help we thought of a realistic idea that could constitute a first spiral of my final project.
This week I will come hell or high water design an enclosure that will house a PCB which will allow me to controll an LED array using buttons mounted on the enclosure.
We also discussed some relevat tools and methodologies which could help me figure this out. Turns out the ever faithful tinkercad has a really awesome parametric design tool wich uses code blocks which are always fun.
Mirriam is a very talented graphic designer and she showed me some tools that could help me in the 2D realm. Cuttle xyz is very useful in this regard.
She then explained the difference between vectors and pisxels and why in many cases vectors are prefered in design, machining and making. This made me sad as I love pixel art.
Me being the creative genius and design powerhouse that I am attempted to make an exact copy of Myrriam’s MS paint sketch and extrude it. As I would soon find out there are many good practices that I skipped in doing so. But you gotta jump in to swim so here we go.
So now that I had extruded a body I needed to split the body in order to make lid for the enclosure. I remember struggling with this function in the past but I used the ‘construct offset plane’ function and it worked perfectly as I was able to ajust the z axis manually and make the perfect cut using the split body function.Oh, by the way I created a cut using the extrude tool where I made a tube that would represent (and I use this term loosely here for reasons that will become clear soon) the hanfle bars of my bike and forgot to take screen shots of it.
Good practises ignored: 1) I should have made the extrusion large enough to include the bottom part of the bracket BEFORE cutting.
2) When using the shell function make sure you notice where the comma is and don’t mistakenly make the thickness 0.5mm.
3) Doccument everything.
…But hey I’m learning.
Thank goodness for the timeline on Fusion 360. I was able to timetravel and make my extrusion large enough to allow for a bottom bracket to be included in my design. Spoiler alert this is not the last time this feature will save me. I added some little feet to the bracket to house a nut and bolt which will fasten the enclosure to the handle bars. I used a trick I learned from Mirriam here using the ‘slots’ and it worked really well.
So now that I had a bottom section to my bracket it was time to split the body so that I could attach and fasten the enclosure. I used the construct midplane function to create a plane and used it to split the bodies.
I then combined the different bodies to create a singe component using the ‘combine’ function.
Poor design practice #4 check your dimetions at the beginning rather than just hoping your design will be the correct scale.
I went and discovered the actual diameter of my handle bars on the second day of designing something that attaches to them.
I messed around with the scale function until I arrived at the right diameter for the cut out handle bar fitment.
Now that I had the correct Diameter hole for the bracket to fit on the handle bars I needed to adjust the length of the enclosure to allow it to effectively house the PCB. So once again I had to time travel, but this time I went all the way to the beginning and adjusted the dimensions of the original sketch. While I was here I rounded the edges of the sketch purely for aesthetic reasons.
The overall design was now significantly longer than I originally expected and so I added extra fitmets so it could be secured effectively to the handlebars.
I ahd to adjust the length of the cutting tool used as a result of this too.
Looking good now its time to add the buttons. So I created a technical drawing to get a sense of the size of the Enclosure and What layout would look good.
I decided I would use rocker switches in my design because thy have a neutral setting which could be useful for things like indicators. Notice how my initial sketching has improved lol.
I used Mirriams panel trick again to make the connectors for the switch an it is completed.
Anothe trick I learned from Mirriam was using components as cutting tools. So I made a little armada of switches. The first batallion were sacrificed as cutting tools and the second avanced and took thier place… their sacrifice was not in vain!
I noticed I had over 30 bodies in the left hand panel so I cleaned that up and combined all smaller parts into their bigger counterparts.
I then Cut ot holes for cables to reach the PCB in order to connect the PCB to external power and output devices.
Image Compression¶
As per the reccomendation of the Great and Powerful Proffessor Gershenfeld I chose Image Magick.
Image Magick is an extremely powerful and easy to use Image editing software which is operated through the command line.
Installation was unremarkable. Just download and click through.
Then I checked that the software was working in the CMD by typing in the name and file extention of the software.
Next I used the “mogrify” function to change the entire folder as I wanted all the images to be .jpg files and not exceed 300x300 pixels. Inorder to activate Image Magick you need to launch the CMD from the folder you have your images and type “magick” and from there we can simply type magick “mogrify -format jpg .PNG” thsi will create a .jpg version of all the PNG files in the folder. We can then get rid of the PNGs by typing “DEL .PNG” and then type “dir” to check that the contents of the folder have been changed accordingly.
I searched the library of Image Magick functions for how to resize images and found this command.
I then used “magick mogrify -resize 300x300 *.jpg” to resize all the images in the folder.
I was successful but maybe 300x300 is a little too small lol.