Hydrus PVD

The Hydrus Mechanical Tube Mod was born from the idea that Tube mods could do with a quick release head.  Allowing users to magnetically attach various attied onto the mod without having to unscrew the 510 thread between swops. 

The magnetic heads would be aesthetically matched with the atomizer thereby designing a aesthetic ecco system of magnetic heads. 

Directives on Design

The design process started with a very simple set of directive

  1. Magnetic Head design
  2. Magnetic ball bearing supported switch
  3. On body engraved style line
  4. Cold Press Cast Decorative insert


During the design period 25mm atomiser where just starting appear, the decision was made to support 25mm over 22mm formfactor with atomiser heads tapering, or bevelling, down to 22mm as needed. 

As magnets will be used to connect both the battery and the 510 head, magnet sources had to be investigated, as well as any potential benefits of having a current pass through the two ring magnets.  The theory was, as ignorant that i was during the design process, was that some level of “clean” power would be imparted during usage. 

18650 batteries where a common choice ideal for personal vaping devices. The alternative was 18500 (more compact, less capacity) or 26500 much bigger, but not as reliable for sustained high amperage draws.

initial design August 2014

Thus we know the inner diameter was going to be 18mm, giving us a wall thickness of 3.5mm wall thickness for decoration and or functional bits and bobs. 

CNC Tube, with cast decorative emblem and button

My software of choice has been always Rhino 3D – perfect for creative blocking out ideas, and very quick in designing machinable parts – relatively accurate.   Later I would learn there are MANY better options for accurate modeling, but the CAD files generated by Rhino is perfect for R&D or generating render models that are dmn accurate for the intended use. 

Delrin was chosen as the insulator material of choice. Delrin is easy to machine and a cheap option… and PEEK insulation material only became practical from 2015 and onwards. 

The simplest choice is based on price. Hence the Hydrus would be designed in South Africa – Manufactured in China…. and so started the most dismal failure that any independent design could immagine…


You can design ANYTHING that you can imagine, with a modicum of manufacturing experience gained from 14 years of jewellry design and, at the time, a year of vaping experience and PLENTY of research. I approached many Alibaba machine shops, and eventually settled on a small Chinese butcher e-cig manufacturer. 

Renderings where sent in for assessment and initial cost implications, shortly followed with STEP files and technical drawings. … now anyone would imagine that that would be enough to figure out if anything could go wrong, or to suggest alterations to the design. but no….

China is VERY literal they will do anything you specked, and nothing more — until it impacts pricing after they start with prototyping and have not taken in account that THEY miscalculated manufacturing costs… Paying them is 100% a leap of faith, and then they start — nearly a month to manufacture 8 prototypes. Credit cards are welcome by the way…. and then you wait for shipping…. and pay import duties, and you start to realise your babies will be in your hands soon – and you imagine all the local and international orders coming your way and you make promotional material and only have stars in your eyes….


The day your box arrives in a dusty carton with plenty of packaging peanuts! So happy! Fresh 18650s layed out. Cameras ready to pictures. and then you start inspecting your pride and joy – everything looks great – Happiness ensues. 

Until you try to use it. 

All hope fades, and you realise that substitution was made in SO many places. Pressfit detail , engineered so that cloning companies could not do it, meant that your Chinese manufacturer made a balls up. 

The single spring you specced turned into THREE separate mini springs, that collapse as soon as current goes through. Atomiser heads that pop off at the nearest budge as three mini springs miss align. 

Voltage drop (from a fresh 18650 battery 4.1V) was a massive 1.5V! effectively reducing the performance of the mechanical to an underpowered potato…

You now realise you are doomed to design iterative updates until you can scrape up your soul and try and figure out what to do next…..  

Hydrus Mech v1 = failed. . . . and your independently funded adventure comes to a close shave with death.

to be continued….

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