I recently bought some spools of printing filament from Sunlu but they have larger holes than the Bambulabs ones I have been using. I decided to print an adapter but, having found a simple model online, it turned out to be a bit larger than I needed. I thought I was being clever by figuring out how to import the STL file into OpenSCAD and then use the resize() command I discovered last week to adjust the dimensions.

Unfortunately it was only after printing it that I realized that, as well as resizing the outer radius to create a perfect fit, I had shrunk down the inner radius so that it wouldn’t fit on on the spindle. The lesson from that one is that I need to consider what all the vital dimensions to a project are and ensure that all of them finish up suitable when I get to adjusting things.

I probably will have another go at the spool adapter but I think, in this case, I’ll generate a new one from scratch with inner and outer dimensions both based on my measurements. The shape is pretty simple so can be thrown together from a few simple elements. I might even think about adapting ideas from some other designs, such as bits of plastic that hold the fit under a low amount of tension, although I don’t want to get too carried away!