Monday, March 11, 2013

Looking at the Competition

Looking at existing products in the rugged, waterproof or otherwise indestructible USB drive market is useful for a few reasons:
  1. It may be that our "best" VIUD already exists.
  2. Compare and possible change our design with what is available.
  3. Get a better idea of prices if we wish to market our drive.
The following are a selection of better products found from searches of rugged, waterproof or indestructible USB drives.

Corsair Survivor

The Corsair Survivor looks like a relatively nice consumer level rugged and waterproof USB drive. It has a nice waterproof rating of 300 psi and its Aluminum case looks like it would take a pretty good beating. The design, in my opinion, is not ideal with a very large cap which may be easily lost. It has a relatively low price range of $30-85.

LaCie XtremKey  

The LaCie XtremKey looks like a decent candidate for a VIUD with a 300 psi waterproof and to a 10 ton pressure resistant rating. The "resistant" qualifier is suspect but with an all metal case it looks like it could handle being run over by a large car depending on the exact type of metal used (they mention a Zamac alloy but not which one). It has a large cap design like the Survivor which I dislike. Its price point is slightly higher at $85-140 but is not unreasonable for such a rugged device.

One notable specification for this drive is its large range of temperatures, particularly its high temperature limit of 200 °C. Although they again say "resistant" this is much higher than any other USB drive I've seen that actually has any temperature ratings (most don't).

Imation Ironkey Basic

The Ironkey Basic from Imation is a very nice looking drive with what looks like a basic metal case which would protect it from everyday bumps and drops but probably not larger accidents. It is rated waterproof under specification MIL-STD-810 which, as far as I can tell, is close to IP67/68 or essentially just waterproof from basic immersion and not pressure rated.

The drive's price is significantly higher than other rugged drives at $90-300 despite being less rugged. This is likely due to the Ironkey's main purpose of being an encrypted drive. Overall a great looking drive but not exactly what we're looking for our own VIUD. In theory if we wanted encryption it could be done at the software level.

Tyukalov USB Drive

The Tyukalov drive is a unique, one of a kind, custom USB drive which is interesting to compare to the consumer type drives previously found. It was made in a limited quantity of 100 at a relatively high price of $200-250 each but managed to sell out in a short period of 3 weeks. Its unique dual cavity design is not particularly convenient but it boosts the highest waterproof rating of 2000 psi of any USB drive I've seen and undoubtedly an equally high rugged rating.

Eternal Case

The Eternal Case is a product that wasn't out when I initially researched and came up with my VIUD design in the fall of 2012 but is remarkably similar. It just goes to show that if you think of a good idea there's a good chance someone else already has or soon will.

There are no explicit ratings for this custom product but from its design I would guess it should be waterproof to at least 300 psi and would easily withstand being run over by a car. Its price is amazingly low at only $40-75, even for a 32GB Titanium model. Based on what I've researched for prices I'm unsure how they can make a profit at this price. The only negative thing I can see is that the design/manufacture is relatively rough looking.

Wrapping Up...

There are other drives that are marketed as "rugged" but the majority don't actually have an explicit mechanical or waterproof specification. Most appear to be just cheap drives surrounded by a thin metal case with a "rugged" label which is not what I'm looking for my own VIUD. 

Even with this relatively small collection of existing true rugged drives it gives us a relatively good baseline on what is currently available and at what price. It also helps narrow down some of our design constraints, or at least what we would like them to be:

  • >2000 psi waterproof rating
  • >10 ton crush rating
  • >200°C for 3 minutes temperature rating
  • $40-300 (depends on capacity, quality, and ultimate rating)

Time will tell whether any of these are actually possible or not....

Thursday, March 7, 2013

Design Details for the VIUD

I listed my mostly arbitrary "design requirements" for my virtually indestructible USB drive in the first blog post and would like to explore and explain them in more details.


Having our drive be waterproof is a relatively obvious requirement even though USB disks tend to be relatively impervious to water just by themselves. If a cheaper drive gets wet it is generally just a matter of drying it out before using it again. The key word there, of course, is "generally". If you try to use a wet USB drive, get it wet with impure water which may cause deposits to form on the circuit board when the water evaporates, or even drop it in something other than water then your drive may not fare so well. I would like a drive so waterproof there would be no worry about getting it wet or dirty.

The other question in regards to waterproof is "how waterproof"?  It is easy to mistake this for a binary "yes/no" question when in fact there are a number of standards such as IP and NEMA made to determine how water (and dust) proof an item really is. But even these are just the beginning: the highest typical IP rating is IP68 which only represents something being able to withstand continuous immersion in 1 m of water. Waterproof ratings beyond this are typically specified in how much pressure something can withstand over a certain period of time.

A quick calculation shows that for every 1 m underwater our pressure increases by 1.5 psi (10 kPa). In my previous job we would regularly make parts that were rated to at least 300 psi for use in water systems and other parts rated to 3000 psi for use in oil and gas, each typically rated at that pressure for at least several hours with no leaks. Exactly how high of a rating we need, or want, for our own USB drive depends mostly on how difficult it will be to achieve although ideally we'd like a pressure rating as high as possible.

Crush Resistant/Rugged

This is a particularly weak point of most USB drives out there. Cheap ones likely wouldn't survive being stepped on and even most metal cased ones wouldn't survive being run over by a car.  In order to meet its namesake of a "virtually indestructible" drive we'd like our design to be as strong as possible without having to sacrifice any of its other requirements, especially its price. Ideally something that would just shrug off being run over by a large car or truck would be great.

Prevent Cap Loss

I simply can't stand USB drives that have a detachable cap with no method of storing it. Generally these caps only last around 27 seconds before they are lost in some unexplainable manner. In order to meet the "rugged" and "waterproof" requirements we will almost assuredly need a cap and so will also need a design to prevent the cap from being easily lost.


Making a VIUD would be relatively easy if price were no object. If we were just making a one of a kind drive then price would be mostly irrelevant but if we wish to market and sell these drives at some point (a fair assumption) then having something more affordable would be advantageous.

The price per drive can be roughly broken up into three categories:

  1. Case Manufacturing - Mass production can greatly decrease the price per unit.
  2. USB Drive Board - Buying something off the shelf in bulk would be ideal.
  3. Assembly - Something that minimizes the final assembly time would be good.
There is also the one time development costs, marketing, shipping, and hours spent on the project to consider to ensure that we don't lose money by making the drives.


This may appear to be a silly design requirement but making a good looking, or even beautiful, drive is important, particularly if we're interested in selling it is as a product.


I forgot about this design requirement initially although it may be one of the more important. We could easily make an indestructible USB drive by encasing it in a 10 kg brick of Titanium. This would more than satisfy all design requirements, except possibly the price, jowever, a 10 kg brick is not something you can drop in your pocket and use anywhere you would use a regular USB drive. Ideally we would want something very similar in size, shape, and weight to existing USB drives, or at least not too far away from.

So it seems our design requirements are complete even if some of them are in the "as rugged as possible" category. It will take some design testing and prototypes to determine exactly how much we can get.