[GreenKeys] [External] Re: empty papertape reels (for 8-bit tapes)

[john at toebes.com]

Doug,
  Those are some excellent pictures.  I made a quick model in Onshape based
on the measurements I was interpreting.  If there is any chance someone
could verify my measurements, it would be appreciated.  In particular, I'm
not 100% sure of the thickness of the outside of the reels.   If we get the
model tweaked, it is really easy to export a STL or STP file for people to
3D print.

https://cad.onshape.com/documents/debbba2925a167ad85461476/w/ce2487daaffd99c
0fbdff960/e/27715fe3df49726eee4106f7

-- John Toebes]
john at toebes.com 

-----Original Message-----
From: greenkeys-bounces at mailman.qth.net <greenkeys-bounces at mailman.qth.net>
On Behalf Of Jones, Douglas W
Sent: Tuesday, August 4, 2020 5:53 PM
To: Dave Wade <dave.g4ugm at gmail.com>; 'Henk Gooijen'
<henk.gooijen at hotmail.com>; GreenKeys at mailman.qth.net
Subject: Re: [GreenKeys] [External] Re: empty papertape reels (for 8-bit
tapes)

From: Dave Wade [dave.g4ugm at gmail.com] -- Tuesday, August 4, 2020 3:57 PM
> Probably need to print them in three pieces, so 2 flanges and a hub.

The reels I just sent to John at tubetestingpros.com a few weeks back were
two-piece reels.  I just found I have two more in my pile.  I've attached
photos (including metric and English rulers in the view).  These aren't
fashion photos, but they should suffice as good starting points if someone
wants to 3d print some reels.  Notice the fairly large round central hole.
This is intended for a light friction fit on the tape winder shaft, so that
the shaft can spin continuously at a speed faster than the reel, with
friction determining the tension on the tape.  The friction was determined
by a knurled screw on the end of the shaft that drives a taper into the end
of the shaft, causing it to flare out.

One half reel has dimples on the end of its three legs that fit sprung bumps
on the other to lock the rotation.  The other half reel has notched ends on
its legs that fit holes on the other half.  Press the legs into the holes
and then twist to lock the two halves together.  It clicks locked, and
unlocks with a click when you twist the other way.

Someone should really make plans for 3D printing something like these, since
they do get lost and break.  I guess they are PVC, and I suspect simple
breaks can be repaired with a solvent-based cement, just like you can glue
Teletype model 33 cases with solvent cement.

         Doug Jones
         jones at cs.uiowa.edu