GLAS Education’s tactile telescope cannot be used to gather light. But as a
teaching tool, it is quite enlightening.
Imagine a telescope that’s been cut in half. Students don’t look through it, they
look into it — or feel inside it. The ingeniously viewable scope came out of a
project called Innovators Developing Accessible Tools for Astronomy (IDATA),
which was funded through a National Science Foundation (NSF) grant. One of
the goals of IDATA was to make astronomical data accessible to blind, visually
impaired and deaf students.
Youngsters are particularly intrigued about the workings of a telescope, said
GLAS Education Director Kate Meredith. And in their desire to learn, they want to
touch and feel the devices.
“Typically, our volunteers and staff don’t like it when people touch their
telescopes, especially the lenses and the mirrors,” Kate said. “So we needed
telescope that we could touch.”
Two feet long and with a diameter of four inches, the tactile telescope is
patterned after a Newtonian reflector telescope. It can be found at GLAS
Education Star Parties where the curious can lay their hands on it.
The late Kevin McCarron, a retired retired science teacher from Oak Park and
River Forest High School in Illinois, was also a talented craftsman with a toolshop
at Yerkes Observatory. In 2017, for the sum of about $30, McCarron took it upon
himself to create the touchable telescope, using pieces of pvc plastic pipes,
scrap wood (properly fashioned) and springs and screws from a hardware store.
But it also has a real mirror and real lenses in a real eyepiece.
In a video made prior to his passing, McCarron pointed out that his telescope is
not real, but a model.
“Does this telescope work? No. In fact we made it so it does not work,” McCarron
said. “The telescope parts are spaced out so it’s easier to explore the components
visually with hands and fingers.”
Now GLAS want’s to distribute instructions so schools and museums can create
their own tactile telescopes.
Ed Sadler, also a retired science teacher who taught at Williams Bay and later
Lake Geneva Badger high schools, and also adept at building stuff, has taken on
the task of creating a simpler version of McCarron’s design and writing some
simple instructions for its construction.
Ed said McCarron’s model is a work of art, but it would be hard for someone else
to recreate. Some of McCarron’s model used real components, like lenses,
mirrors and a telescope focuser.
“It became apparent that some of the pieces would be hard to come by,” Ed said.
“We decided that perhaps we should make it more accessible for people to put
The idea was that many of the parts could be made from items available at
hardware stores, like pvc tubing, standard screws, and wooden doweling, Sadler
said. And other items were created by 3D printing. For example, instead of real
mirrors and lenses, the mirrors and lenses in Ed’s version are opaque plastic.
But the faux lenses and mirrors are 3D printed discs that are concave and
convex like the real mirrors and lenses.
Ed said that in the years since McCarron made his model, 3D printing has
become more common. Most educators and model makers know someone who
can do 3D printing, Ed said.
Ed didn’t do the work alone. He needed help with the 3D printing, and James
Cudworth provided that assistance. James is the son of Kyle Cudworth, retired
Yerkes Observatory astronomer and former observatory director, and he grew up
at the observatory and got to know its workshops and learned 3D printing there.
James said he stopped by GLAS to deliver cookies, or something, and got
lassoed into the project.
It wasn’t difficult, he said.
“I put it on freeCAD and got it printed, it went pretty smoothly.”James
Helping James was William “Liam” Finley, an 8th grader at Lake Geneva Middle
School and student at GLAS Education. Liam said he worked on printing the
main focuser in the eyepiece. Most of it went smoothly, but there was one difficult
“It was really hard (to figure out) how to get the screw holes angled on the design,” Liam said.
But already experienced with 3D printing through school, Liam figured it out. “The
rest was straight forward,” he said.
Ed took the pieces, hardware and printed, and built a prototype tactile telescope,
about 16 inches in length. This January, Kate took it with her to the American
Astronomical Society’s annual conference in Seattle.
Meanwhile, Ed said he is now working on some simplified instructions so others
can create their own tactile telescopes.
“The project is ongoing,” he said.