Thursday, 30 August 2012

The Water Closet

Having a toilet and bathroom in a motorhome is something which divides some people. Many travellers find the idea disgusting, whilst others wouldn't travel without one. For my money, that single occasion where you wake up at 3am, you're parked in a town centre, its absolutely pissing down, and the dodgy meal you ate has given you less than 2 minutes before you thoroughly embarrass yourself, makes it worth carrying a crapper around with you. It might waste precious floor space, it might smell if you haven't emptied it for a while, and it might not be the porcelain throne you are used to reading the Sunday paper on. However, if on one single occasion it saves you having to crouch behind a bus stop in your pyjamas, in a hurricane, with a bunch of taxi drivers staring at you in horrification, it is definitely worth it.

With that in mind, one of the first major thing pieces of work I did on the inside of Jim was to install the bathroom. However, given that I might only use the room once or twice a day, I was loath to make it any bigger than absolutely necessary, and set about planning it to make it as small as possible, whilst still being usable.

Below is the space I started with, after installation of a window to add some light, and the hatch to allow me to empty the toilet without having to drag the excrement filled cassette through the living space, which would be a step to far even by my low standards of hygiene.

Jim the Trucks bathroom, prior to installation

With this in mind, I designed the room around the footprint of a Thetford cassette toilet and matching shower tray, designed for use in small caravans.  In addition to these items, the room needed to house, a sink, a storage cabinet, a radiator, and a shower; all in a space noticeably smaller than the cupboards I use at home to keep my clothes in.  Which is why I thought that Water Closet was a surprisingly appropriate name, although my closets at home are significantly larger than the space I had allowed in Jim to shower, shave and sh...

Saturday, 25 August 2012

Dogs and ladders

Dogs are generally awesome, and mine is certainly no exception. Boris (our golden retriever) makes a great tofu stir fry, and can recall Pi to 47 decimal places, but sadly one of the things Boris cannot do is climb ladders.

The first time this became a problem was when I was visiting a friend on his boat at low tide; the gangway was too steep and Boris flatly refused to lose his dignity trying to descend it. On this occasion Boris retired to the car whilst I demonstrated my agility to him.

More recently I noticed that Boris's ladder issue would become a problem when we started travelling in Jim, as the only easy access is via the nearside door in the box body, entered using steps recessed into the side guard.

recessed entry steps, electrics and gas lockers and side door

I've often laughed at the array of bulky and expensive solutions many motorhomes and traveller vehicles use to make entering the vehicle easier - electric steps that mean you have to lift your foot 4cm less when getting into a van, huge wooden ladders strapped to the bumper when travelling. Of course there are also many elegant solutions, such as steps that fold away into the bodywork, or entry doors that fold downwards to form a staircase, but these seem to be limited to manufacturers of expensive overland trucks .

I'd previously not given the entry of the truck much thought. The steps in the body work are easy to use for a biped with opposing thumbs, but realising that I needed to make a dog friendly solution I started looking around for a cheap and effective solution that worked well when parked but also didn't pose a headache when travelling.

Having spent many occasions lusting after old army trucks in the past, I had seen the UK MOD communications body trucks with their well built aluminium steps fixed to the back. The steps looked tough enough for a life on the road, and if they don't fly off and kill someone when the army are throwing their vehicles around off-road, I was sure they'd be fine on Jim. The steps are made from pressed and cast aluminium components (thus fairly light) and have adjustable legs that allow them to be used on various vehicles and on non level ground, perfect. With this in mind, and having waited many years for a valid excuse, I went up to the next Witham Specialist Vehicle Tender. For those not afflicted with incurable mechanophilia (sadly I didn't make that term up!), you may not have come across Witham, but for people like me, it is the equivalent of Mecca. Witham have the sole right to sell every vehicle disposed of by the armed forces in the UK, and consequently the place is rammed full of vehicles that leave me weak at the knees.

Captured Russian APCs and tanks at Witham Specialist Vehicles

Witham aren't in the business of selling small cheap items, and so the only way of buying a set of the aluminium steps was to bid on a lot of 8. I don't suppose there is much demand for these steps if they don't come attached to a truck, and so I won the lot. Some of them were irreparably mangled, some of them needed a of tweaking, and a few were practically unused.

aluminium MOD entry steps, used on Bedford and DAF communications and workshop bodied trucks

I kept a pair of good ones for myself and sold some of the rest, covering most of the cost of buying them and picking them up. I've got three pairs needing a bit of work left; if anyone want them, you can have them for a bottle or two of something tasty.

Unfortunately, this was the easy bit over.

Friday, 24 August 2012

Continuing work on the speakers

I've got both speakers painted now as the weather has been pretty good in London. I did one coat of primer, 3 coats of undercoat, and 3 coats of satin. The finish is pretty smart and it'll fit in nicely with the white interior I'm putting in Jim. The panels I'm lining Jim with and building the furniture out of are laminated plywood; I considered building the speakers out of the same material but I wouldn't have been able to produce the curved section as the polypropylene laminate would have either cracked or prevented me from getting the tight radius. I'd have also felt obliged to cover the plywood edges with teak mouldings as I'm doing elsewhere, which is pretty absurd even by my massively opulent standards.

I've had the time to load the driver and fit the hardware to one of boxes .

Volt FR220.1 8" coaxial hi-fi speaker

Volt FR220.1 8" coaxial hi-fi speaker

 Volt FR220.1 8" coaxial hi-fi speaker, showing the M20 top hat bracket mount and speakon socket

Volt FR220.1 8" coaxial hi-fi speaker, showing the M20 top hat bracket mount and speakon socket

I haven't installed the headunit or amps into Jim yet, but I had a chance to listen to the one I loaded yesterday in the house with my hi-fi. I tested the speaker off of a Crown DC300 amplifier which puts out a maximum of about 175w per channel at the 8ohm load this speaker presents . First impressions are great, the sound is awesome and f*ck me does it go loud. I may have tuned it a little high as it doesn't go as low as I expected, at a guess I'd say it starts rolling off about 70hz, but I'll play around with the ports this weekend.

Playing it alongside one of my bookshelf hifi speakers, it sounds clearer, without the boomy bass and missing midrange that a lot of small hifi speakers have. It doesn't go as low but the hifi speaker was making death noises when this speaker was only just getting warmed up! I threw most of one side of the amp into it and I got scared before it showed any signs of distress. Both of these together in Jim will be able to go louder than I'll ever need for sure, and plenty loud enough to drown out the 230 horses screaming under the cab when crawling at high revs up long ascents.

Here's a brief video to give you an idea of the sound. The camera mic was distorting when I got too close. I apologise for the wonky view and explicit music! I hadn't realised the track was quite so offensive until I listened back! Send your kids out of the room before you listen to the clip!

video





Thursday, 23 August 2012

How it really started...

For me, the dream of getting in a truck and driving around the world didn't start with a love of travel. Really it started with a love of jungle music.

At 16 I got my first set of record decks and my love affair with dance music began. I am too ashamed to recall most of the music I played back then, but gradually my tastes changed; and with my choice in music becoming more obscure, it became difficult for me to find clubs which would interest me. Being a youth in London, the natural destination for a lover of jungle and techno were the squat parties which shook the industrial areas of East London each weekend.

Within a few years I was totally hooked, and it wasn’t long before I started buying equipment with some friends and started my own sound system.  


Early Disjunkt sound system, showing PD1850 loaded 1850 horns, Martin Audio phillishaves, and JBL biradial horns
Some of the best times of my life were spent thrashing our sound system in filthy warehouses in Edmonton, but as with all things, it became harder for us to get our fix.  The parties in London started to merge into each other and each weekend seemed like a continuation of the last.  As a result we started travelling further afield with the sound system, to outdoor raves in the UK and to teknivals in Europe.  We travelled in a ‘94 Mercedes 310d van, which was constantly overloaded (by about 1 tonne) and often had four unfortunate passengers on benches in the back of the box body.

Ex-Disjunkt Mercedes 310D box vanv

Ex-Disjunkt Mercedes 310D box van on a tour of European teknivals in 2005

It was on my travels to European teknivals that I began to realise that there was life beyond the old 310.

Wednesday, 22 August 2012

Hi-fi building

A couple of weeks ago I took Jim to Brownchurch in leyton to have a roofrack made. Whilst the truck was away, I took the opportunity to start on a project which for which I didn't need the truck next to me.

A year or two ago, I bought a cheap pair of speakers which has been removed from an install in a church. The cabinets were useless, being badly tuned chipboard monstrosities, but the drivers were a pair of 8" coaxial units made by Volt Loudspeakers, a well regarded UK manufacturer popular in studio and high-end hifi circles. Whilst the truck was away I started building a pair of boxes to rehouse the Volt FR220.1 drivers.


All loudspeaker driver are characterised by a set of variables called the TS Parameters; these define various characteristics such as the resonant frequency of the cone assembly, the motor strength, the compliance of the suspension, etc. On their own they don't mean much to me, but by using suitable software, they enable you to model a driver in a theoretical enclosure, and predict the response of the speaker. Most modelling software can predict the response in term of frequency, impedance, phase, excursion, etc although for a simple box like I needed, I was only interested in the frequency response.

I used the free, easy to use, and well regarded WinISD software. The software models various types of enclosures, but for a simple (mostly) full-range speaker, most people will choose a ported enclosure, which is essentially a box of determined volume with a port tuned to alter the frequency response. If I was going to build a more complicated enclosure such as a rear loaded horn, there are a number of more advanced programmes I could use, but such an enclosure would be complete overkill for a motorhome and would go down very badly with Naomi.

The drivers I was using are optimised for very small enclosures. Using WinISD I worked out that a box with internal volume of about 9.5 litres was ideal. Using a larger box would extend the frequency response a little lower, but the gains were small, even when doubling the volume.  Tuning the box to 60Hz gives me a frequency response which is flat down to 80Hz and usable to around 60Hz. This is not as low as many good hifi speakers but is a good deal better than most car, and truck audio systems and most people would not notice the notes missing at the bottom. Cutting these speakers off at 60Hz or so also conserves precious battery power, as it takes considerably more energy to reproduce bass than the higher frequencies.


At any rate, with the music I love and the way I tend to listen to it, people would be taking me to the doctors if I didn't also fit a sub in the truck.

Tuesday, 21 August 2012

Blog revival!

So when I made this blog, I was really just adding a placemarker so that when I had the time and inclination, I could expand it and update it. With work on the truck recommencing properly after a few years of slackness, I think it's time I revived this blog.

I have added a gallery section, showing work to date on some areas of the truck. I will be updating this periodically to bring the blog up-to-date with the work that has gone on.