Second acrylic prototype (learning fusion360)

A project log for A Hacker's Wedding Centerpiece(s)

Im getting married :D. I've been put incharge of making the coolest* centerpieces ever! (*coolest acording to me)

bveinabveina 01/04/2018 at 21:250 Comments

well this took alot longer than i thought.

i had set out to make a second revision of the acrylic that would adorn the circuit board, but the cad cam process just took to long. 

  1. design everything in 3d in sketchup
  2. copy every 2d face, and reorient them to be planer.
  3. use a sketchup plugin to export the faces to svg format.
  4. import the svg into corel (importing straight into rd works causes problems...)
  5. export that to RDworks, the cam program for my laser cutter.
  6. colorize the layers and finally export them to a *.RD file on a flash drive
  7. carry flash drive to laser cutter, load and go.

steps 2 through 6 took several hours. once was enough. i thought, there must be an easier way, so i embarked on a journey to learn fusion 360. four days later and a lot of head banging later, i emerged with a pretty good handle on fusion 360 and a workable parametric model of my centerpiece.

This project was just complex enough for me to really have to get into the details of this cad program. 

The Base

the base of the model shows the PCB and the outlines of where the acrylic will eventually go. and everything on it starts with a sketch. 

just about everything has been made a user parameter. ive placed two inscribed polygons centered on the origin, the side length of both has been set to user parameters (in the image above 55mm and 27 mm). ive also placed points where bolts and leds will eventually end up. that is for this sketch.

next i designed a quick bolt and led to nominal dimensions.

no i did not put threads on the nut....

The rotate operation

this one operation is the focus of the entire model.

first i place a bolt and two leds for one panel. they are locked to the points on the parametric sketch i made for the base.

then grab the bolts and leds and rotate!

now its time to build up the acrylic

The Acrylic

back to the drawing board...well actually back to the sketch. fusion360 keeps everything you ever do and the order you do it in (this will become important in a minute). we make a new sketch with two rectangles. they are linked to the pentagons in the base sketch.

we can use the same user parameters we have used before for the side lengths. i also cut off a bit from each corner so the acrylic doesn't overlap. then extrude!

now i COULD just repeat the same rotate operation i used for the bolts, BUT a better option would be to TIME TRAVEL!!!!! 

Time Travel (The Fusion 360 timeline)

i did mention that fusion 360 stores everything you ever do and when you do it,  what i didnt mention is that you can go back in time and modify little parts of what you did in the past. you can even take some things that you did in the future and bring them past.

so to simplify my life (and trust me, it does simplify things) i dragged the sketch and extrude operations before the rotate operations as shown above. Then, i edited the rotate feature to include the acrylic. then i warped forward in time, everything is redone in order.

we will need something to bolt the acrylic together however. add another sketch.

in none of these sketches do i worry about kerf whatsoever. this would result in very loose fitting parts but i will be dealing with the kerf in a later stage. based on the two holders i made i used joint offsets to palace them centered on the circuit board at fixed heights.

now i add in the modifications to allow these pieces to fit together by adding a sketch to the extruded face of the acrylic.

all of the dimensions come from user parameters. then i do another extrude THROUGH the existing acrylic and cut holes for the tabs,bolts,and leds. Also, since i moved the sketch back in time to before the rotate operation all of the cuts propagated through.

this post has gone on pretty long at this point. ill cover laser cutting this design in another post.