The Situation
Living in a "housing collaborative" with around 15 other people, it's important to have good vacuums.
Our favorite regular-duty chorded vac was a Dirt Devil Featherlite Cyclonic:
Unfortunately the manufacturer stopped making the filters used by that model... I smell planned obsolescence...
So it hung around unused in our workshop until...
The Adapter
I set out to make an adapter which would allow us to use a widely available filter with our trusty old vacuum.
Purchases
I bought a widely used filter (the f2) with a receiver made for some other vacuum at a thrift shop.
The Fun Stuff!
The filter, original or f2, goes inside a separate assembly dirt devil calls the "dirt cup."
The dirt cup contains the "dirt cup baffle," and together these form the cyclone separator.
The original filter was held into the top of the dirt cup by the baffle, which twist-locks in place. However since the f2 is not the same shape as the original, this would require changing the internal geometry of the baffle.
Far easier to reuse the receiver I got with the filter, and have the f2 attach to the top of the dirt cup independently.
So first I cut the functional geometry out of the receiver - the bits which the filter twist-locks into.
Then I cut a clearance hole out of the original filter mounting plate (part of the top of the dirt basket), since the f2 is a bit longer than the original filter.
Finally I designed and printed an adapter ring to hold the functional part of the receiver in place. The receiver and adapter were pressed into the top of the dirt cup and secured permanently with superglue.
Our favorite non-shop-vac vacuum lives again!