This is replacement bobbin for a Woolee Winder for a Lendrum spinning wheel A Woolee winder is a type of flyer than automatically fills the bobbin as you spin without the need to stop and adjust yarn on the hooks or slider.
Because of the nature of the plastic I'd recommend using a nylon (fishing line) tension band instead of a cotton one.
The files were printed with 3 layers - top, bottom, and sides and infill of 35%. You should be able to adjust accordingly. I use both rafts and support but you may or may not need them.
This bobbin was made with 5 separate parts and requires sanding and gluing to assemble.
A jeweler's file may be needed to clean up and fit the gear on your Woolee winder. It only took me about 5 minutes to get it to fit (do this before gluing.)
Let me know if you have any questions or if you want a bobbin for a different wheel.
Best of luck.