Flan jar lid

Nowadays people are familiar with recycling. But some people forget recycling is only the third alternative in "reduce, reuse, recycle." The goal of this project is to reuse small glass jars instead of tossing them into glass recycle.

The jars came from an eight-pack of flan in little single-serve portions. The jars were sealed with a layer of foil, which was sufficient to preserve the flan until the expiration date, but the foil top was not reusable.

In order to reuse these jars, I need to make some lids. At first I thought a simple revolve would do the job - draw the profile of a lid with a lip, revolve it 360 degrees, done! Sadly it wasn't that easy.

Problem #1: neither ABS nor PLA were flexible enough to make a practical lid. What I had drawn up is the shape of a Tupperware lid but my material did not have the flexibility of Tupperware lids. I thought this was solvable by making the lid precise enough so that it only needed a tiny bit of flexibility to work. That's when I ran into the next problem...

Problem #2: The flan jars were not perfectly round and varied from jar to jar. This was perfectly acceptable for their original usage of sealing with a foil top, but tremendously inconvenient for me! It's not practical to try to match the precise shape of each individual jar just to make a lid.

To work around these  problems, I switched the design so that the lid slides on to the jar sideways. Half the lid is rigid, reinforced by a strong lip to hold on to the jar. The other half has a small lip at the far end keeping the lid in place. The lack of a strong lip gives the lid a tiny bit of flexibility, so the small lip can be bent out of the way and the lid can slide off the jar.

The lids make the jars useful for holding small tools and parts.