As said previously most people use PVC pipe for the hull construction, Looking round the internet for ideas I have come across Ian Leverington’s site ROV Robot Submariner, that sells a how to guide for building an Remotely Operated Vehicle, complete with on-board video camera for under £200 for £6.50; I have bought a copy of the guide. soI can use it as a starting point for my design;

Also on the internet I found a kit called the SRV-1 by Dry Dock Products, sold via Mike’s Subworks, it looks like a simple design; and suggests that it is also possible to use the motor pods for fully functional vector control instead of requiring the use of the dive planes, or rudder for steering.

The rotating thrusters allow you to power the sub nearly straight down, or up to the surface, with the dual motor control option, the sub will be able to spin round on its axis.

Most model submarine hulls are made of fibreglass. but more RC submarine kits are being made out of ABS or Styrene plastic because of the reduced cost and ease of construction; however I don’t think these materials are as strong as PVC pipe, due to the nominal wall thickness being much thiner, and not designed for the external pressure being as high (Most model submarines have an operational depth of between 2 and 8 feet).

There is a hole in my water tight box…

While making a completely sealed water tight box that is resistant to pressure would be relatively easy; it leads its self to some problems;

1. Just how do you get all your wires in and out?
2. How do you make things move outside the water tight box?
3. how do you keep it watertight?

Wires

The holes where wires pass through your pressure vessel are the easiest to deal with; as they can be made secure using potting compound, like Epoxy.

There is a good How-To on this very subject at http://www.homebuiltrovs.com/howtosealingwireexits.html, Home Built ROVs show all the cables having there insulation stripped out in the epoxy bung; so that ingress outside the pressure vessel, will not propagate along the conductor, or bundle into the hull;

As this makes total sense to me; its the method I shall go with at the moment; unless I can think of something better. although I am sort of a fan of having two sets of water proof bulkheads with a monitored interspace between them (working at CCFE has left some impression ).

Push and Pull Rods

These tend to be delft with by tight bushes, or ruber bellows; neither of which I am convinced are as impervious to ingress as I would like; I guess that using the two in combination, and filling the bellows as much as possible with hydrophobic grease would help.

Another option would be to use magnetic sliders; meaning that there would be no penetration of the pressure vessel.

Propeller and rotary shafts

Prop shafts for RC boats are generally not designed for large pressure differentials, however there are some prop shafts that are designed to be ‘waterproof’, one example consist of a brass tube and inner bearing housing with a stainless steel shaft. The outer bearing is made from Delrin and the inner bearing from sintered Bronze with a lipped G ring seal that make these tubes water tight.

I don’t know how these would cope at larger pressure differentials.

Water ingress detectors

The easiest way I can think of for ingress detection is the use of Printed circuit boars with a large number of parallel tracks so that any moisture will complete the circuit;

A similar pattern can also be laid directly onto the inside of the pressure vessle with copper tape.

The voltage signal from these sensors can then be passed to the control circuit.

Hobby ROVs

With an increased interest in the ocean by many people, both young and old, and the increased availability of once expensive and non-commercially available equipment, ROVs have become a popular hobby amongst many. This hobby involves the construction of small ROVs that generally are made out of PVC piping and often can dive to depths between 50 to 100 feet but some have managed to get to 300 feet. […] Most hobby ROVs are tested in lakes where the water is calm, however some have tested their own personal ROVs in the sea. – From Wikipedia

As with most water craft (boats etc) the part of a ROV that is underwater should be water tight; while boats have a large amount of them above the water that can be full of holes, ROVs and Submarines loose out on that grace, also boats can be almost water tight; and rely a number of methods of either sinking very slowly; kicking ingress water out faster than it comes in (pumps, sponges, etc) and or using prop tubes that are interspaced with grease that stops water at atmospheric pressure sneaking in, However ROVs operate under larger presure (RC Subs tend to not be designed to operate as deeply as miniature ROVs).

Under Pressure

Pressure increase at depth, as the little diagram acquired from CalcTool shows the greater the depth, the greater the pressure; I used their assumption of the density of sea water to be 1025 kg/m³ (‘Fresh’ water is less dense), which means that pressure increases by approx. 1 atm with each 10 m of depth.

I ran the calc tool a small number of times and came up with the following graph; The Calculator gives the total pressure – not just the pressure due to the water, so it includes the 1 atm ambient air pressure at sea level.

This 1 atm ambient pressure should be the same 1 atm as inside the ROV at the surface, so the net force on the hull at the surface should be 0 atm.

As well as atm I ran the pressures as kgf/cm^2 and all the way to 60 meters below the surface;  I doubt very much if I will need to build that level of pressure resistance into my first attempt; but its worth illustrating.

Also at some point it may be worth re-running this in SI units (1 atm = 1.03 kgf/cm^2 =  101 kPa)

Most hobby ROV builders use PVC pipe from plumbing suppliers, despite it comming with the following warning:

PVC pipe tends to shatter into small splinters or shrapnel when it explodes and not all PVC is pressure rated.

NEVER pressurize PVC pipe with air, hydro-testing (water) is the only way it should be done. If you don’t know what that means DON’T TRY IT, PERIOD.

However since PVC pipe is a known for hobby and home made ROVs I will follow their lead. however I am not happy about using re-purposed bilge motors for thrusters; and am sure I can come up with something more graceful.

More Posts will follow (follow this project on “My 1st ROV” Project Page).

• Fisher-Price Online – some of these games will work with this thing too. They’re free and not too bad.
• Knee Bouncers – An awesome ad-free site supported by annual membership.

If you know more sites with similar please leave them in the comments below.

I may also build a Baby Interface Device for my niece

I am using the Arduino IDE (from arduino.cc) and the Teensy Loader (from PJRC) this gives me the following pin out:

My current code for the moment sits at:

#define NORT 0  // North
#define EAST 1  // East
#define SOUT 2  // South
#define WEST 3  // West

#define LEFT 6  // Left Click
#define DOUB 7  // Double Click
#define LOCK 8  // Click Lock
#define RIGH 9  // Right Click
#define SCRO 10 // Scroll Lock

#define LED 11   // On PCB LED
#define CLED 6  // Click Lock LED
#define SLED 7  // Scroll Lock LED

void setup()
{
  // initialize the four pins for the D Pad
    pinMode(NORT, INPUT_PULLUP);
    pinMode(EAST, INPUT_PULLUP);
    pinMode(SOUT, INPUT_PULLUP);
    pinMode(WEST, INPUT_PULLUP);

  // initialize the Five Pins for the Buttons
    pinMode(LEFT, INPUT_PULLUP);
    pinMode(DOUB, INPUT_PULLUP);
    pinMode(LOCK, INPUT_PULLUP);
    pinMode(RIGH, INPUT_PULLUP);
    pinMode(SCRO, INPUT_PULLUP);

  // initialize the Three Pins for the LEDs
    pinMode(LED, OUTPUT);   // This is the LED on the Teensy PCB,
    pinMode(CLED, OUTPUT);
    pinMode(SLED, OUTPUT);
}

void loop()
{
  int X;
  int Y;
  int speed;
  X = 0;
  Y = 0;
  speed = 1;  // number between 1 and something bigger, if speed = 0 well… FAIL

  if (digitalRead(NORT) == LOW)
    {
      X = 1;
    }
  if (digitalRead(EAST) == LOW)

    {
      Y = 1;
    }
  if (digitalRead(SOUT) == LOW)
    {
      X = -1;
    }
  if (digitalRead(WEST) == LOW)
    {
      Y = -1;
    }
  Mouse.move(X * speed, Y * speed);
}

I would appreciate any one who can poke my code for me to help me write better code

This is my set up at the moment, I haven’t yet got a desk; so I work on my bed,

My mum works with a young man with special needs, who among other things has trouble using a computer using off the shelf consumer Human Interface Devices, while mouse alternatives are available, such as the OPTIMA Joystick (here) they start at at £169.00 plus the cost of the extra buttons (here) at £27.00 per; I spoke to the young mans mother; and came away with a rough idea of what would be useful to him as an interface.

Why a Joystick as a mouse?

• Many computer programs, e.g. drawing-programs, demand the use of a mouse.
• Many users have difficulties in handling a standard mouse.
• The joystick mouse is used instead of a standard mouse, but demands less motor ability from the user.

A while ago I remember watching the Make Video on The AWESOME Button, and remembered one of the cool features of the Teensy USB, after looking round the site I ordered two. Also a while ago I looked into making my own MAME (Multiple Arcade Machine Emulator) box, and as part of that research I came across Balltop Joysticks & Arcade Buttons from Arcade World.

I now have a box of Joystick and Buttons to play with and two Teensy USB boards, so over the next few weeks I will have a go at making a much more accessible version of the Joystick, but designed to the young mans needs.

While other people have had some success with this kind of project; their starting point tends to be a USB gamepad and some software to make it act as a mouse; where I am looking to try and make it as system agnostic as possible

The ideas for requirements are

• The joystick is handled like the wheelchair joystick.
• Mouse pointer speed is adjustable.
• The mouse-keys can be used in two ways,- with or without toggling.
• External switches are optional.
• To facilitate double-clicks, the joystick mouse has an automatic double-click-key.
• Presents its self to the OS as a generic USB Mouse

I plan to make the buttons external to the joystick as that will allow the mouse to be operated by two hands. I also plan to put LEDs in some of the switches to give visual feedback on function.

The following button functions should be supported (with an * signifies a LED for feedback)

• Left Click
• Double Click
• Click Lock *
• Right Click
• Scroll Lock *

Scroll Lock turns the Joystick off mouse pointer mode and makes the up and down act as up and down on a scroll wheel.

Although Lion shows up as available to install on the App Store, it returns an error when you try to install it

I tried to re-download OS X Lion on my macbook pro, but it knows that its installed already, and prevents you from re-downloading; however there is a work around, if you hold down the ‘option key’ (⌥) you can click on it to re-download.

After copying the install file to the mac mini, and trying to run it, the installer returns the following screen:

Telling me that MAC OS X 10.7 requires at least 2 GB of memory, which is still annoying since my mac mini only has 1 GB of memory; however this shows that the only thing the installer seems to be worried about is my lack of RAM…

There seems to be a  way around it, download a copy of Pacifist fromhttp://www.charlessoft.com/

Pacifist is a shareware application that opens Mac OS X .pkg package files, .dmg disk images, and .zip, .tar, .tar.gz, .tar.bz2, and .xar file archives and allows you to extract individual files and folders out of them. This is useful, for instance, if an application which is installed by the operating system becomes damaged and needs to be reinstalled without the hassle of reinstalling all of Mac OS X. Pacifist is also able to verify existing installations and find missing or altered files*, and Pacifist can also examine the kernel extensions installed in your system to let you see what installer installed them, and whether the installer was made by Apple or a third-party.

Pacifist is not yet compatible with Mac OS X 10.7 “Lion” so the next steps were completed on my Mac Mini:

The File you need to open is OSInstall.mpkg in the Install Mac OS X Lion (right click ‘Show Package Contents’) > Contents > Shared Support >

Jump to Resources, and click on the padlock in the top right

The File you need to edit is the Distribution File

Changing var minRam = 1048; to 1024, re-package the distribution file, and see if the changes help (here is my copy of OSInstall.mpkg.zip)

Now while I now get the following screen, suggesting I can now attempt the install

It returns the following error

I will have to have a look, and see if the hackintosh community can offer any help.

There are a number of advantages to iTunes & iPod Audiobook format when using an iPhone, iPod or iTunes to listen to Audiobooks:

• Because audio books are most of the time quite large files, it’s unlikely that you listen them in one piece. Your iPod remembers the position where you stopped listening the last time. So when you continue listening to your audio book, maybe days later, you don’t have to waste time finding the right position to start. This even works, if you are listening to music or other audio books in the meantime. — even after resynchronising your iPod.
• You can adjust the reading speed to your personal preferences. This seems not that important to me but it can be useful in certain situations.
• There’s a special Audiobooks entry in the menu of your iPod.
• Audiobooks can have chapter stops within them
• Audiobooks are automatically skipped during shuffle.

While the remember location feature is available for books in the MP3 format, the iPod format (.m4b) provides you with a single file for your entire audiobook, while having the option of preserving chapters.

I am playing with AudioBook Builder (Torrent link to allow for more testing before purchase(Updating will break the SN))

I have been testing AudioBook Builder with Terry Pratchett books, This post shows the Discworld Novel “The Light Fantastic” being converted to a single m4b file:

The files as acquired from TPB

Starting up AudioBook Builder

Create a new Project

Setup meta-data for the audiobook, including art work (acquired from Wikipedia)

Drag files from Finder to the chapters window

Click the ‘Join’ button to make a continues file; with no bookmarks (Remember position fulfils my requirements) you may want chapters.

Click on Build Audiobook, and in a few moments the files will appear as a single book in iTunes

If you need to edit the MetaData you can right click on the file and edit it in iTunes. at this point you can now delete the source files, and the Project file.

For more information on what you can do with The Pirate Bay and other Torrent sites, have a look at this post of mine: Book 10 – Cancel Cable: How Internet Pirates Get Free Stuff

About twice a week I catch the Oxford Tube to London, in general they are very comfortable; and clean, one of the nice things that they advertise is wireless internet, which would but or three things,

One: You have to agree to be good on it:

Two: They filter everything through Vodaphone’s Content Protection system (I guess to stop you being Nawty…) which also means images are down scaled; and some sites I use are blocked.

Three: It Drops out more often than its up on the journey.

Oh and yes, if you need technical support there is a tech support line:

However its 0906 5400 256, and charged at 50 pence per minute from a land line; not much use when on a bus.

Despite all this; i guess it is a very good local Wireless LAN.

I first learnt about theMediaNet through working at Greenbelt in the media team, where I was helping to put together media for there online offerings (Videos I worked on can be found on PhilipMcGaw.com).

In the Academy, I was part of the Video/TV team, and our brief was to produce a short video clip about gaming, We produced a short Documentary featuring one of the Keynote speakers (mp3), Jason Gardner (Fuse Think Tank).

Our guidance came from Jeremy Higham, Director of J&E Higham, a great time was had learning how to use the equipment; and I found the introduction into media very useful.

The Video we produced can be seen below:

Huge thanks to Jeremy Higham, Jason Gardner, Tarsila Burity, Nicola De Boo, Daniel Gaine, Josh Lynch, Ralph Mann (and), James Robinson, and Sophie Willis for making the weekend an enjoyable and informative experience.

One thing I some times worry about, is how to make a backup of my Mac’s Bootcamp partition. there are some sites that give you details; but they all point back to a app called WinClone:

If you want to make a quick clone of your bootcamp partition, or you want to migrate your bootcamp partition to a different machine, Winclone makes it a breeze. Winclone will create an image of your Windows partition, and allow you to quickly restore it to get you back up and running quickly.

For this you will need both WinClone and NTFSprogs; they are both free; (At the time of writing WinClones official site is dead).

First install NTFSprogs; this little app allows your mac to talk to NTFS partitions; (this will not work on FAT32) then run WinClone:

And that is that; while you cant get Time Machine to back up your Bootcamp Partition natively, you can back up images of it.

Apparently you can also use WinClone to change the size of your Bootcamp partition.

By booting into windows and renaming the disk so that the first character in the label is a full stop it can now be changed and hidden. You cant change its name in OS X if its formatted as NTFS.

Fulla is the name of my ByteMark server; it is mounted via ExpanDrive using SFTP (SSH).

Chris Fehily’s “Cancel Cable: How Internet Pirates Get Free Stuff” is an interesting getting started guide to bit-torrent, while I knew most of the content the book covered, it did hold a few bits I didn’t previously know, while I don’t know if i would recommend this book to my peers; mainly because most of the geeky people I know, have a similar knowledge level to me, I would push it past some one like my parents to have a read of.

This is another book that I picked up for the Kindel.

I am currently in the process of moving all files and settings from my two old computers; as well as files stored on two external drives, and other media; as well as de-duplicating files.

So thats another one of my Day Zero – 101 things in 1001 Days challenge complete.