This part was designed in OnShape. You can find the OnShape document here.

OnShape models are inherently parametric. I created 2 special variables called #Diameter (which was 30 for the STL file) and #Width (which was 85 for the STL file).

You can read a bit more on my blog post.

evannguyen created a 65mm wide remix over here.

BrownA created a 105mm remix over here

El_Cuajinais created a variant in Fusion 360 for Taulman spools here