Affordable materials for geoscience teaching demonstrations

Portable Platforms - The DJ Table and the HT3

DJ Table complete setup

Introducing the DJ Table! As the first DIYnamics table that incorporates portability in the design, the DJ Table is the perfect kit for schools and universities who want to showcase advanced fluid dynamics phenomena in their classrooms and lecture halls.

The DJ Table is a three part system consisting of modified cart, a high-torque record player, and a tank. The modified cart has standard utility shelf posts such that the height can be adjusted by one inch increments and the only tool needed for assembly is a mallet. The cart is also the only part of the system that requires assembly and is easily a one-person job. We offer a variety of options for both new and used record players, but highly suggest scouring the internet (and local garage sales) for second-hand record players. Record players that lack a tone arm or functioning audio ports may seem like junk to music enthusiasts, but are perfect for fluid dynamics experiments! Finally, we provide a few different options for tanks. While we recommend our custom-designed tanks with centered holes for mounting to record players, if you have your own tank, we also provide options for elevation blocks such that you don’t have to worry about the record pin being in the way. Overall, the pricing for the DJ Table ranges from $600-$1500 depending on your choice of record player and tank. This averages to about 1/5 the price of our more advanced system, the HT3.

The DJ Table is well suited for schools looking to share a kit between classrooms or lecture halls. The DJ Table’s modified cart has locking wheels and the system maintains a minimal footprint for easy storage. Situated on the cart, the star of the DJ Table is the high-torque record player which can generate rotation rates from 17 RPM to 117 RPM (depending on the specific model). This rotation range makes the DJ Table perfect for rapidly rotating experiments such as:

  • Taylor columns
  • Column collapse and frontogenesis
  • Ekman pumping
  • Centrifugal forcing
  • Corner vortices (in a square tank)
  • Spin up demonstrations
  • Columnar (vertical) convection

An example of columnar convection can be seen below. The visualization is accomplished with green food dye distributed using a spray bottle.

Columnar Convection

HT3 complete setup

Introducing the HT3! The HT3 is our most ambitious kit to date. Boasting a powerful turntable, meter-scale tank, and built in visualization deck, this system can be used for demonstrating geophysical fluid dynamics everywhere from a classroom or lecture hall to a museum or a outreach science festival.

The HT3 is a multi-part system optimized for portability, accessibility, and ease of assembly. The custom acrylic HT3 tank has a maximized diameter while still fitting through a standard doorframe and comes pre-drilled with mounting holes on a 2.5-inch lip for the HT3 visualization deck. The visualization deck consists of a polycarbonate plate held above the tank with three legs and it allows users to place sensors in the rotating frame of the tank, including phones and cameras to record and stream video. The tank sits on a powerful turntable, capable of maintaining a consistent low rotation rate with over 25 gallons of water in the tank. Finally, we encourage those who want to invest in an HT3 to purchase the THC (Taylor-Henry Cart) - a multi-purpose cart designed by our team to make the HT3 a broadly useful and accessible teaching device. Low to the ground to enable children to look over the tank, the THC sits on 5-inch locking casters which turns the HT3 into an all-terrain vehicle. With the THC, the HT3 system can easily be carted from classroom to classroom, or across campus from lecture hall to lecture hall. The lower deck on the THC is ideal for storing your power, as well as dyes and other visualization tools. Additionally, the cart’s handlebar can be bent to provide a platform for controls, or completely stowed under the lower deck to make 360 degrees of viewing available. Most importantly, the entire system (both the HT3 and the THC) can be assembled without any power tools! The cost of the HT3 kit with the THC is $4,800.

The HT3 system is a flexible device that was designed with large-scale outreach in mind, but with careful set-up and leveling, it has the potential for being a research device. The visualization deck can also be used to house measurement instrumentation including motion tracking and thermometry systems. The HT3 turntable is capable of rotating from 0.16 RPM to 13.3 RPM which makes this system ideal for experiments such as:

  • Thermal wind flows
  • Ocean Garbage Patches and Ekman Pumping
  • Baroclinic instability
  • Columnar convection
  • Mechanical turbulence (i.e., Great Red Spot experiments)
  • Non-rotating evaporative convection (solar-style convection)
  • Rossby waves

The following video shows a baroclinic instability demonstration on the HT3.

Visit the DIYnamics Kits page here to learn more about the original Do-It-Yourself rotating tank platform — the LEGO Table — and its newly-released successor: the Technics Table. If you are interested in sharing your experiences with the DJ Table or the HT3, feel free to contact us on Twitter at @DIYnamicsTeam or email at