New Spiral

Pretty soon I'd like to try DIY processing some cine film for the first time. Processing stills film is pretty straight forward, but super 8 cine film comes in 50 foot (15 metre) lengths. This is not going to fit inside a Paterson tank and anyway, there just don't seem to be any 8mm film spirals either.

Folks seem to use Russian Lomo spiral tanks to do this, but I can't quite bring myself to send lots of good money away to buy a hunk of soviet-era bakelite from ebay. I'm guessing that many of the available tanks will be broken or have bits missing by now.

So what about designing the vector graphics for a new spiral and having it made from plastic? I would think this could be a job for a laser cutting or 3D printing service.
It might look something like this...

By my calculations this would need to be about 220mm in diameter, the channel for the film is 1mm, as are the ridges between the winds. This is a theoretical design, but who knows if this would work, or if the film could actually be loaded into such a thing? The next step will be to find a cutting/making service that could make this up for me at a reasonable price. Please comment below if you know of such a service.