Shake Table mk 3

Several years after the first (wooden, “mark 1”) shake table was done, my kids had moved on to a different school. Obviously, I wasn’t about to play favorites and deny my younger son the joys of a fun science education — though, don’t worry, Bay Area Covid restrictions handled that part for me. So it only made sense to start work on another shake table.

(Yes, this is the “mk 3.” The mk 2 — a big 24×24″ table — is a story for another day.)

Project Details

  • Completed: April 2020
  • Owner: Donated to a local elementary school
  • Materials: t-slotted framing, nuts & bolts & springs, acrylic
The completed mk3 shake table — a black t-slotted aluminum frame with a clear acrylic top, the central drive flange visible inside and a crank handle at the front

Goals

For the mk 3 design, I wanted to up the game with a few key changes:

  • Use off-the-shelf components readily available from McMaster, and avoid custom match-drilled woodworking
  • Open it up visually, so the drive mechanism is on display for the kids using it
  • Make it lighter, but still durable
  • Keep the cost down as much as reasonable, so others could build one for their own schools
Back view of the assembled table, showing the t-slot frame and the clear acrylic top

What’s different

In the end, the mk 3 leans entirely on t-slotted framing and its joint components. The drive wheel sits central to the top plate, and the top plate itself got smaller so it never swings outside the envelope of the base during operation. A clear plastic top provides the visibility I wanted, and threaded inserts again let you tie down whatever’s being tested. Instead of PVC pipe rollers, this one rides on proper t-slot framing rollers.

The bare t-slot frame on the bench before the acrylic top went on

The other major difference is that I fully designed and documented this assembly in SolidWorks. That let me capture every component and its length accurately, and generate proper 3D assembly instructions.

Close-up of the crank handle on its triangular mounting bracket
Detail of the drive coupling — the central flange and its washer-and-nut stackup on the shaft

How it works

The student cranks the drive handle at a steady pace. That rotates the centered plastic flange and works the main drive springs, turning the rotational motion into linear, table-top motion — with a bit of give at the ends, which is exactly what the springs are for.

Open-source hardware

Since this one is for education, it felt important to open-source the design. The only thing keeping me from putting even more construction detail in place is the time it takes to do it — but there’s plenty here to build from. I’ve found a 12×12″ table top to be more than sufficient for elementary-school use, and you can scale it readily from there.

mk3 Shake Table — Plans (PDF)Download
mk3 Shake Table — Bill of Materials (XLSX)Download

Videos

This build happened to overlap with our local school’s extended Covid shutdown — the thick of the lockdown-and-snitch-on-your-neighbors era of the pandemic. To keep sane, we invited some neighborhood friends to build towers and drop them off on our front porch. We’d run them on the table, capture the carnage on video, and post the results for the group to enjoy. Some great work came through: