- Watch the video above.
- This is a team project. Talk with your partner about how
to divide responsibility for the work.
- Download the SolidWorks design Pascaline-v7.zip and extract all the files
to your file server directory.
- In SolidWorks, load the file Pascaline.SLDASM. This will in turn
load all the other assembly and parts files. SolidWorks will try to
find the files using a directory path that doesn't work on your
computer. Simply tell it you will search for the file, and direct it
to the version7 directory. Once you help it find one file it will
know where to look for the rest.
- In addition to the assembly and parts files, there are also
drawing files that you can use to create DXF files and laser cut your
parts once you've modified the design.
Part 1: The Design
- The first part of the assignment is to modify the Pascaline
design to make it more artistic.
- Start by spending some time exploring the Pascaline in SolidWorks
so you understand how the various assemblies are put together.
- Last semester, many people added artwork they engraved into the
front, back, and side panels of their Pascaline. One group even added
wooden ornamentation; see the picture below (click for larger versions):
- Another way to play with the design is to change the shapes of some of
the components. For example, the accumulator gear uses a circle of screws,
but the plastic itself does not have to be circular. What if it had a more
irregular shape, or had designs cut into it? What other component shapes could
you play with?
- Yet another way to change the design is to change the color
selections for parts. (But you'll need to do more than just that to
earn a good grade on this part.)
- Be careful when modifying parts that you don't break the mechanism
by causing collisions/interference with other parts.
- When you've completed your design, load the drawing files
(they'll update automatically) and save them as DXF files. Color them
appropriately using DraftSight.
- Make a zip file containing your DXF files, two
screenshots of your modified Pascaline viewed in SolidWorks, and a
short note (as a plain text file) describing the modifications you
made to the Pascaline design. This will be your hand-in for Part 1.
Part 2: Construction
- Cut your parts on the Rabbit Laser. You can get acrylic sheets from the usual place.
- Follow these assembly instructions to build and test your Pascaline.
- Your hand-in for part 2 will be the physical Pascaline. We will
examine them and grade them. Then you can keep yours if you want to.
Click here for a complete
parts list. Your metal parts will be available in your project bins.
Take acrylic from the piles in the lab; try not to waste any.
- Use the right screw for the job so you don't have excess metal
sticking out past the nut. Here's how to calculate the correct
length. Each plastic part is 1/8 inch thick. The nut or standoff
requires 1/8 inch of thread. So if you're attaching a threaded
standoff to a piece of plastic, you'll need need a 1/4 inch screw (1/8
inch for the plastic piece and 1/8 inch to thread into the standoff.)
Similarly, if you're screwing two plastic pieces together using a nut,
you need 1+1+1 = 3/8 inches of thread: use a 3/8 inch screw.
- Don't rip open your screw and nut packs. Cut a tiny opening in
one corner, and squeeze out the parts as you need them. This keeps
things neat and protects you from having all your parts spill on the
floor if you drop a pack.
- Use the thread locking fluid! If you don't, your screws will
quickly come loose and your Pascaline will not work properly. Eventually
it will start falling apart.
- Don't coat the entire screw with thread locker. Just squeeze one
tiny drop onto the screw at the point where the nut will rest. Wipe up
any spillage so it doesn't discolor your parts.
- Use pliers, not your fingers, to hold the nut as you tighten the
screw down. You'll get a tighter fit that way.
What to Hand In
- Hand in your DXF files, two rendering images, and a brief
description of what design modifications you made, via Autolab. This
part is due Wednesday, November 18.
- On Monday, November 30, during office hours, we will have a
"Pascaline checkpoint". Adam or Meg will check your Pascalines to
identify any problems with the assembly, answer any questions you
have, and verify that your mechanism is operating properly.
- Your physical Pascalines are due Tuesday, December 1.
- 7 points for customization and properly laid out drawing files
- 3 points for properly colored DXF files
- 3 points for cutting the plastic
- 7 points for correct assembly and demonstrating a fully working replica
Back to 15-294 course home page
Last modified: Tue Nov 24 06:05:16 EST 2015