TU56 DECtape takeup reel needed

Christian Corti cc at informatik.uni-stuttgart.de
Tue Dec 21 03:08:05 CST 2021

On Fri, 17 Dec 2021, Paul Koning wrote:
> Interesting idea.  A while ago someone posted a picture of what looks 
> like a "go/no-go" gauge for DECtape reels.  It is marked with the 
> dimensions of the two sides: 2.504-2.505 inches for the "no-go" end, 
> 2.494-2.495 for the "go" end.  So that tells us the hole diameter is 
> 2.500 +/- .004.  Can 3D printing deliver that sort of tolerance (with 
> hobbyist-price machines)?

That's huge four milli-inches, that's about 100µm. Hobbyist machines 
usually have a Z (layer) resolution of at least 100µm and a position 
accuracy of about 20µm. The specifications of my Adventurer 3 say 50-400µm 
Z resolution, 11µm X/Y accuracy and 2.5µm Z accuracy.
For a spool it's the X/Y accuracy that matters (and the material of 


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