15-394 Assignment 1: Build an Automaton
Design an automaton in SolidWorks similar to the LittleMan exercise we
did in class, but don't just make another figurine. Be creative. The
design critera are:
- Must have at least four links. They don't all have to be part of
one figure; you could have multiple figures, or a figure and a sun or
moon or vehicle. Be creative!
- Must use gears that don't all have the same number of teeth.
- Must include a crank you can turn to power the mechanism. No link
(other than the crank gear) should be directly driven.
- Don't forget to include spacers where needed.
- Simulate your automaton in SolidWorks. Remember to turn on
SolidWorks Simulation in the SolidWorks Add-Ins tab, and then change
the animation type from "Animation" to "Motion Study.
- Save an animation file from your simulation. To do this, click
on the Save Animation button which is in the same row as the Motor,
Damper, and Solid Body Contact buttons, but further to the left. Use
the AVI file format.
Make a Drawing
Generate a realistic rendering of your mechanism in SolidWorks:
- Do File New and create a new Drawing (not Part or Assembly) document.
- Make sure the units (bottom left corner of the screen) are IPS
(inches/pounds/seconds) and not MMGS or Custom.
- Set the sheet size to "custom" and enter 12 inches by 12 inches as the
width and height, then click "OK".
- Insert a part onto your drawing. Remember to hit Escape to cancel
insertion of additional views of the part. In the properties manager,
set the part to use sheet scaling, not custom scaling.
- If your part has circular holes that show up with centerlines (cross
shapes) in the drawing, click on and delete the centerlines.
- In the Feature Manager Tree, right click on Sheet1 and select
Properties. Verify that the sheet scaling is 1:1; somtimes it
defaults to 2:1.
- Lay out all your pieces on this one sheet.
- Save your file as a SolidWorks drawing file. This is important in
case you want to go back and edit any of the individual parts; the
drawing file will automatically update, but a DXF file will not.
Make a DXF File
- Once you've created your drawing file, choose "Save As" and save the
file again as a DXF file.
- Run Inkscape, set the file type to DXF (it always defaults to DWG),
and open the DXF file. Turn off the "Use A4 scaling" and set the scale factor to 25.4
to convert from inches to mm. Zoom out and you may see a "SolidWorks
Educational Edition" banner in the bottom left corner. Click on the
banner lines and hit Delete to remove them. (If running on a MacBook
you will need to press function-Delete.) Then type control-A to
select everything, and set the color to blue.
- Hit Escape to deselect everything. Then click and drag to
select any internal shapes that should be cut first (such as the
little holes in your gears), and set their color to red. If nesting
one gear inside another, choose another color, such as green, for
that. The idea is to be able to cut shapes from the innermost
outward, because when a piece of plastic is separated from the sheet
it can drop slightly and thus fall out of alignment with the
- Select "Save As" in InkScape and set the file type to "Desktop Cutting
Plotter (AutoCAD DXF R14)". Click "Save", then set the base units to
"mm" and click "OK".
Fabricate and Assemble
Take a photograph of your actual automaton.
Post the rendering and the picture to Piazza in the thread provided for this purpose.
- Assign materials to your parts. To do this, open each part file
and, in the feature manager tree, right click on Materials. You can
either choose one of the popular materials listed in the pop-up menu,
or choose Edit Material for a wider range of choices.
- Go back the assembly and verify that your parts are colored
correctly. You may need to remove an existing appearance attribute in
order to see the material's color. To do that, click on the part,
click on the beach ball (Appearances icon), and click on the red X to
remove any unwanted appearance attributes.
- Go to the SolidWorks Add-Ins tab and select PhotoView 360.
- A new tab will appear to the left of SolidWorks Add-Ins called
"Render Tools". Switch to the Render TOols tab.
- Click on Edit Scene, and in the "Appearances, Scenes, and Decals"
menu on the right side, click on one of the basic scenes, such as
"3-point faded", and drag it into the graphics window.
- Click on the green checkmark to accept that scene, or click on
the red "X" to choose a different one.
- Click on the Preview Window button to see what the final
rendering will look like. You may need to rotate or translate your
part, or zoom in or out, to get the view you want.
- Click on the Options button to adjust the resolution of the
rendered image. The default is probably good enough, but you can
change it if you wish.
- Click on the Final Render button to pop up a Final Render window
and generate the rendering. This will take a little while.
- Click on the Save Image button in the Final Render window and save your image.
Hand in a zip file handin.zip containing the following:
Due date: check the class schedule.
- Your SolidWorks part and assembly files.
- Your animation file.
- Your rendering image.
- Your photograph of the automaton you made.
Grading (10 pts)
- 4 pts - At least four links in your automaton; different/custom character
- 0.5 pts - Crank
- 0.5 pts - Different gear ratios
- 2 pts - Motion study
- 1 pt - Reasonable files and style (colored DXFs, etc.)
- 2 pts - Assembly and documentation (picture)
- 1 pt (BONUS) - Extra creativity (multiple characters, interesting links, colorful, etc.)