In the ongoing saga of designing siphons for making layered drinks, we have previously presented the Mk II mini siphon for making two-layer shots, which works quite well.  However, the nature of the self-starting siphon means that the volume of each pour is fixed.

But what if there were a way to modify the volume of the pour so a three-layer shot could be made?

Background:

Those who have taken a look at the 3D model of the Mk II have possibly noticed that there is a second part that can be printed.  The second part (i.e., the “3-layer adapter”) allows for pouring three perfect layers into a shot glass.  It can also be used to make a smaller two-layer shot, if a 2/3 sized shot is more your speed.

Design:

The 3-layer adapter works by reducing the size of the reservoir from half the size of a shot glass to only a third the size of a shot glass.  It also makes use of the fill line to help hold it in place when installed.

Cross section of Mk II mini siphon with 3-layer adapter.

Slicing & Printing:

The 3-layer adapter can be printed without supports, and is intended to be printed inverted, as shown in the image below.

Sliced 3-layer adapter and the expected wipe block for a two-color print.

Of the 3-layer adapter prints made for testing, one of the four warped slightly.  That failure occurred when we attempted to print a siphon and its adapter at the same time.  So, it is recommend that the adapter be printed as a separate print from the siphon itself.

Testing:

As with the siphon without the adapter, testing went very smoothly.  An example pour of a 3-layer shot can be seen in the video below.

Surprise Results:

Accidentally making cement mixers. Turns out, commercially available orange-colored vodka or other options are too acidic for cream-based liquors.

Possible Improvements:

Since there are six possible orderings of three fluids, only one of which is correct, would it be possible to somehow exploit the automatic sorting ability of a wave tank to sort the fluids without needing to know their correct order ahead of time?

Conclusion:

The MkII layering siphon can easily be adapted to make three layer shots by restricting the size of its fluid reservoir, allowing for perfect 3-layer shots with without the need for carefully pouring liquids over the back of a spoon and hoping you get the measurements right.