A Very New Look

So I've been trying to have a breakthrough with my design and by stripping it down to the basics.  I have been struggling to work with the bucket so I thought I'd try to get rid of it.  I started trying to piece together the core parts of the project; the shell the hose and the vacuum.  I started to work with the ideas of making a flexible shell out of just the plastic bags and something around them to provide more protection. Then the challenge has been to make a fully sealed plastic bag.

First attempt at making plastic bag shell.  2 bags one inside the other sealed together by melting but it didn't hold.

small plastic shells testing there durability with coffee inside

more pictures of the the small test shells

-Annie

A New Look

In discussing the degrees of freedom of the vacuum casting system, I realized that my current method of bolting the silicon may not introduce enough variables for people to experiment and innovate.  I'm looking into gaskets and toggle clamps to make more removable mechanisms for holding the shells or bladders in place.  I'm looking into bucket with different lids, which would make the entire clamping mechanism smaller.  
Jose and I also talked about demystifying the vacuum casting, like putting holes in the bucket so people know what parts can be broken and which are important to keep airtight.   

A toggle clamp in the lab

-Annie

The Lid

I got a fancy bucket with a air tight lid.  To modify it to attach the silicon shell, I cut out the middle of the top.  Silicon and polypropylene that the bucket it made out don't have a common adhesive.  This meant I had to find another way to keep them together.  To keep them together, I wanted to bolt it to the top of the bucket.  I laser cut a ring with 28 holes in it to fit around the top of the bucket.  I cut out the middle of the bucket and drilled matching holes around the outside.  Then, using a hole punch i put holes in my piece of silicon and put some sil-poxy around them.  I used a couple 1/4" bolts to hold the pieces together.

laser cut acrylic ring with holes 

punching holes in the silicon

The lid with the acrylic ring and silicon partially bolted in

Close up of the silicon seal

-Annie

Fitting the Vacuum

 I cut the vacuum down to size so it fit in the bucket but it needed support and all of the parts, such as the power button, the power cord and the air hose still had to stick out.  I cut foam to shape and used caulk to stick it to the bottom of the vacuum to provide support and stability.  I also cut holes in the bucket to fit the accessories.  I put the power button in its hole.

Foam being clamped to the bottom of the vacuum

plastic washer to fillin gap from the power cord

hole for the power cord (same size as hole for the air return)

Power Button snapped into place

The back of the power button

-Annie

new vacuum and new bucket

So I have to fix the strength of bucket problem and to do this I'm using a stronger vacuum and making better seals.  I bought a new special bucket with a airtight twist top seal and a stronger wet/dry vacuum.

The new bucket

just the vacuum 

the vacuum cut up and pieced back together in the bottom of the bucket

-Annie

Summer UROP begins

I (Annie) got approved for a summer UROP (Undergraduate Research Opportunities Program) so I'll keep the blog updated even though the D-Lab Health class finished in May.  D-Lab got a whole new lab space on Mass Ave, and it's very nice to have more space.

So progress...
for our final class presentation, Megan and I made a prototype and were able to evaluate its weak points.  The major point that we want to fix is getting the vacuum to be strong enough.  The first steps to fixing that involves maybe a new vacuum but more importantly getting better seals on the shells and making shells that are shaped so the vacuum doesn't have to hold them stretched out as far (the more stretch the more force required)
Another point that we had trouble with was the interior shell that held the coffee.  The vacuum bags we bought were too big so we cut them and glued them back together.  The only problem was glue failed, and so did guerrilla glue, hot glue, epoxy, giant clip, staples and anything else we tried to hold it closed.  In the new lab to day I found a plastic sealer which i tested on a scrape bag that I had cut the bottom off.  The sealer made a very strong seal(nobody could pull it apart) and I am very excited that something might work.  Pictures are shown below of the wonderful seal

The little sealer and the plastic bag

The wonderful seal

Even the corner seals!!

-Annie