TU56 DECtape takeup reel needed

[Ethan Dicks]

On Fri, Dec 17, 2021 at 10:13 AM Paul Koning via cctalk
<cctalk at classiccmp.org> wrote:
> > Has anyone tried 3D printing these?
>
> 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)?

What you can do is print with extra shells (2 layers is one default,
depending on your slicer), then print using ABS, which will shrink
1-2% (so you often print at 100.1% and caliper for
dimensionally-critical items) _then_ since it's ABS, you can
vapor-smooth with acetone and remove ridges and improve top layer
bonding, *then* turn on a lathe to spec - but trying to remove less
than half a filament diameter.

I think that technique would work.  I wouldn't just print and go
unless I at least smoothed the tape path to prevent adding wrinkles.

-ethan