Monday, 30 April 2012

Simples!

See, the most successful advertising campaign for years has even got me saying it, but this really is simple and effective. This weekend we are off to Ironbridge for one of our favourite shows, Meccanuity 12. This three day event always has a theme and this year the theme is stationary steam engines. There is also a competition for the best audience participation model. With this in mind we decided to build a few models for the younger visitors. At a recent meeting of our local Meccano club, one of my fellow members had a few small steam sound generator kits for sale. These little kits are aimed at the novice electronics hobbyist and are a bit crude. The thought of a small motorised steam engine model that also made a sound seemed like a good idea.

A simple modification makes the helping-hands stable
I have not made one of these little kits for over 30 years so it was time to get stuck in. the first thing I discovered was the little 'helping hands' is top heavy. I found myself  worrying more about toppling the thing over than burning the digits! Fixing it to the bench is not an option as it need to be portable and besides there are no fixing holes provided. This is not a problem as boring a couple of holes in the base is a simple job. Cast iron is much easier to drill than softer materials due to its high carbon content. Clearance holes were bored and a larger bit was used as a countersink due to the fact there was not enough room get my HSS rose countersink, bit set in the drill chuck, centred over the holes. The stand was fixed to the MDF base using a couple of wood screws. Now the stand is perfectly stable and my fingers are devoid of burns - Simples!

Ralph.

Sunday, 29 April 2012

Where do you keep yours?

A contractor's saw is a good substitute for a larger piece of kit
and stowed under the worktop, it takes up a minimum of space
 My workshop is probably bigger than most built in the garden of a terraced house, void of side or rear access (everything has to be brought through the house and that includes machines as well as building materials. This is a limiting factor but it does not mean the basic machines have to be sacrificed. The practical limitations mean that nice old lumps of green, cast iron woodworking machinery are ruled out but it doesn't mean that I have to make do without a tablesaw or for that matter, a bandsaw. A bit of lateral thinking has enabled me to have the benefits of both.

My home-made panel jig is the most used jig in the workshop
The table saw is in fact a contractor's saw mounted on a small cabinet fitted with lockable caster wheels large enough to roll around without getting stuck on the smallest of obstructions. Luxuries like sliding tables and out-feed tables are also out of the window making way for extending material supports (an optional extra from DeWalt) and a home made panel cutting jig.

Dust extraction is provided by a portable 'dustbin' style extractor. When not in use the extractor is stowed under the end of the woodworking bench and the tablesaw is rolled away next to a cupboard and under the worktop taking up less space than another small cupboard. To achieve this bit of shoe-horning the saw is stripped of fence, guard and saw blade, the latter being wound down below the table surface. Once stripped of all its protrusions, the saw and panel jig becomes part of the scenery. It is a bit of mucking about but it is worth it to have the use of a table saw on the odd occasion it is required.

Ralph.

Friday, 27 April 2012

More silent running...

...Track and landscape contours

Getting there - The underlay will be trimmed flush with the end of the baseboard
when the glue has dried

Yesterday I built the frame and set the track bed in place. Before I could lay the track underlay the landscape contours needed to be cut and fitted. The internal parts are cut from expanded polystyrene foam 'rescued' from packing material. The outer contours are made from plywood and cut to shape using jigsaw. It is worth taking a bit of time at this stage. I have been a bit slap-dash in the past and it can never be corrected after the event. No matter how much effort is applied trimming and filling, it still looks like it has been trimmed and filled! Another little trick, that will save time later, is to cut two profiles for each end.

The end profile boards are cut in matched pairs. The second
one will be used on the adjacent board
The second profiles are used as the end of the adjacent baseboard frame ensuring a perfect match. Once the profiling was completed I laid some oversized strips of high density foam over the MDF track bed. These are deliberately cut over-width so that the hard shell landscaping can be fixed to this overhang creating yet another mechanical break. This is not a total isolation, as the hard surface will connect the shell to the track bed. I am hoping the very thin and light amount of material will transmit little or no vibration into the frame - time will tell. Staying on my recycling theme I found some old cork wall tiles in our loft and thought they would make perfect track underlay for the fine scale (SMP) OO flexible track. I am not sure if you can buy cork wall tiles any more (shows you how long we have lived in our house!) but a strip of the standard cork underlay would do the job if you have not got any old wall tiles kicking about - I knew they would come in handy one day!

Polystyrene intermediate formers and multi-layered
track underlay helps to keep noise transmission to a minimum
 
The whole lot will be weighted down overnight and left to dry. I have used a PVA glue (Original Titebond) to glue the wood together and the underlay down. I like Titebond and have been using it for a decade or more. it has plenty of 'grab' and cures quickly. Any PVA will do the job, white or yellow, it is a matter of personal choice. However, I would recommend buying it in bulk as it is much cheaper that way. I usually buy the odd small bottle and keep refilling it from the bulk container making it much easier to handle. For model railway use I would not recommend the 'permanent' or type II or III versions of PVA as they will not wash out of clothes and if, like me, you prefer to apply the stuff with a brush and mop up with a sponge it will ruin both if not washed out before it cures. When everything is dry, the ends of the underlay will be trimmed flush and the woodwork sanded ready for undercoating. The track will also be glued in place using PVA.

Ballasting will be carried out by laying it loose and 'solidified' it using diluted floor polish. When dry, the ballast will will hold the track in place, without the need to use track pins, thereby maintaining the mechanical separation. I will show you the section again, in a few days time, once I have laid the track and let you know if it runs any quieter.

Ralph.

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Thursday, 26 April 2012

Silent running...

...well almost!

I must admit that if you had told me that I would be considering adding sound to a model railway 20 years ago I would of told you that was the last thing I would do. Today sound has come on a long way from the the vinyl LP record of steam/diesel train sounds and the portable record player. Digital Command Control (DCC) has revolutionised the concept completely with sound chips and on-board speakers as well as resynchronisation of the sound to the actions of the locomotive. The ability to programme the chips (easily) from the hand-held controller make it all the more attractive.

Silent Running - we hope!
Sounds good? Yes, but for me there is still a problem - it' TOO LOUD! Go to any model railway exhibition and you will see fantastic layout where superb attention to detail has been lavished on all the visual aspects. Trains are run at realistic speed within a well throughout operating schedule the sound is so load that they are audible even when out of sight. and far away. Having never exhibited a layout with sound I can only presume there are a couple of reasons for this. One maybe the operator is in the wrong place to be able to judge the volume from the viewer's position and increases the volume until he (or she!) can hear it. As most DCC controllers (other than the most basic units) are walk-around models, either wired or wireless, there is no real excuse for this.A more likely explanation is that the volume is cranked up to mask the roar that is generated and then amplified by the baseboards as the train runs along a solidly laid track and track bed.

Wouldn't it be nice if the viewer could hear a train in the distance only faintly and the sound to become crisp as the train passed buy and to diminish as it disappears into the distance. This does happen on some of the larger layouts as physical  distance will make this happen. But what if your layout is not 40ft long? The only way to do it is to reduce the volume coming from the on-board sound system and to drastically reduce the mechanical noise created by the train running over the layout. One way to do this is to introduce mass into the baseboards. Filling them with concrete would do the trick but my make them a bit on the heavy side! Another solution is to mechanically disconnect the track and the trackbed from the baseboard framework yet still holding it in place.

The plywood-underlay-plywood sandwich is very strong
but time consuming and pricey




To this end I have been experimenting with laminated floor underlay tiles and have built sections of rail bed laminated up from plywood-underlay-plywood sandwich. Although this system is very strong when dry, and would need fewer supports over a given length than convention single sheet road bed, it is not cheap and involves a lot of fabrication. A much simpler method I am testing at the moment involves using small pads of the underlay material glued to the top of the risers and the track bed glued to the pads with no screws or nails. This should dramatically reduce the transmitted noise between the road bed and the frame.

The risers shown here with the underlay pads separating them from the track bed
The next step will be to separate the ballasted track, which will be laid on ⅛ inch thick cork, from the road bed using ⅛ inch thick high density foam. Come back over the next few days and see how successful the sound proofing is.

Ralph.

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Wednesday, 25 April 2012

Ah! Dween-O!

The stand up bench -woodworking mainly
For the past couple of weeks I have not been doing much in the workshop that justified a post. In fact I have been involved in a right-Royal sort out. I got to the stage where I was spending more time looking for stuff than actually doing anything - you know how it is. In a perfect world there is a place for everything and everything in it's place. Well, that's the plan and I think I have more or less got there. The trouble is, my workshop has to accommodate woodworking, model making, photography as well as anything else that needs fixing, modifying or investigating. Now it is all ship-shape I can actually find things and I have space to do things - a job well done and worth the interlude in proceedings...

The sit down bench - mainly modelling and a bit of electronics
What started this long overdue penance, was the realisation that I could not find some electronic components I wanted in order to build a simple voltage regulator to power a motor at a constant voltage less than the available supply. OK let's step back a bit. A while ago, Sue and I purchased a very large collection of Meccano. There was so much of it that we had to make two trips in Sue's Swedish estate car (you know the one, made from recycled fridges!) As this collection was purchased for a fellow Meccano enthusiast in Stoke, we really did try to get it all in one load as it is a 270mile round trip to Stoke from sunny South East London. There was so much that it took two trips!

I digress, amongst this lot was a MotorVator. For those who are not familiar with the said item please take a look HERE. This is a bespoke device aimed at the Meccano enthusiast. Although the MotorVator is rather dated it has a very attractive Meccano interface being painted in Meccano colours (either Red or Yellow) and the metal case is punched with holes that are compatible with Meccano making it easy to incorporate it into a model. After several attempts at getting it going I finally recruited the help of my pet programing Nerd, and good friend, Tim Surtell (It's OK, I am not being rude, he calls me a Geek - but I can't understand why!) after a few minutes of bashing code and muttering he made it do what it was told.

Tim was here discussing another project and the subject of the MotorVator had come up in passing. This prompted Tim to encourage me to take a look at the Arduino. "The what?" I said. Tim went on to explain what it was, I was none the wiser. After he left I took a look at some of the online tutorials and was hooked. There is no better way to learn something new than to get stuck in and have a go. Arduino is an open source enterprise meaning that the whole thing is available online for free - you only have to buy the hardware and this you can build yourself as the information is all out there on-line. However, buying the official Arduino boards does supply some funding for the project. Prices are low enough to make it not worth building your own. You can buy the basic board, the Arduino Uno, for less than £20.00 post free, here in the UK. Mine came with a USB lead and a few LEDs for the princely sum of £18.49 from phenoptix.com . I placed my order in the afternoon and the Arduino arrived the next day in the post - Brilliant!

This is it, the Arduino Uno board - small and compact
That was Saturday morning. Sue and I were off to The Magic of Meccano show at the Kew Bridge Steam Museum for the day so It was not until that evening that I could get around to having look at what I had.The first thing to strike me was the size - or lack of it. It is really compact, making use of  Surface-Mount Device (SMD) technology (these micro components, especially the LEDs have lots of potential in the world or modelling, especially Model railways). The instructions and software is available for free download from the Arduino official website: arduino.cc . Within a few minutes I had downloaded the software to the trusty laptop and after following the online instructions had the drivers down loaded and installed. The Arduino software defalts to port COM3. This proved to be 'inconvenient' on my laptop so after a bit of Googleing the error message I discovered that this is not an unusual problem and the answer is to reset the upload to another port. COM 9 worked for me.

I am now at the stage where I can make it do what it is supposed to do and I have even written and modified my own lump of code. This may not seem like much to some of you reading this but for me this is a big leap into the world of digital electronics and microprocessors - something I didn't think I would ever entertain. Mind you, what do I know? I used to think digital photography would never catch on...

Tuesday, 24 April 2012

The changing face of Maplin Electronics

Ever since the early 70's I have had a passing interest in electronics. Usually this has been associated with another hobby such as railway modelling, automotive or audio. It was at that time that I could not wait for the next copy of Practical Wireless to hit the shelves of the local newsagent. Buying components involved popping in to the electronics shop at the end of the road - yes they did exist in those days. The man behind the counter spent his days repairing all sorts of electrical goods such as televisions and portable record players - Remember the Dansette

Alternatively a trip to Mitcham was required to visit the trade counter at Home Radio. The counter was above the shops and a narrow staircase delivered the visitor to a counter where a brown-coated gentleman complete with notepad and freshly licked pencil would appear. It was a bit intimidating as their core business was feeling the pinch and the hobby was in steep decline. By the 1980's most of the "radio shops" were disappearing - Home Radio dissipated shortly after my visits of the 1970s. It was a good idea to have a list of your own as the usual greeting was "Yes mate?" meaning "OK, what do you want? my tea is getting cold and I suppose you want a lot of little bits and pieces" Unbeknown to me at the time, I suspect the guy in the brown coat was counting the days.

The Home Radio catalogue was a thin looking thing, even though it contained over 200 pages, with lots of lists and images, mainly of dated looking (even then) Bakelite products. The Maplin catalogue was a whole different matter. They had the mail-order game sussed. Every order came with a handful of vouchers (redeemable against the next order) that looked like they were typed onto Gestetner sheets, printed and torn up with the aid of a rule in their then mail order HQ in deepest Essex . The thick catalogue was fully illustrated - albeit in glorious monochrome - and it was full of diagrams, projects and thousands of components aimed squarely at the emerging hobbyist mail-order market of the day. They certainly got me hooked I would get home to find the little red card on the mat from the postman informing me that my order was ready for collection from our local sorting office. If I was home early enough I would shoot off and collect my goodies before my Mum had a chance to ask me what I wanted for tea. Even today I am not averse to ordering from them or even visiting one of their many retail outlets. However today it is a very different world to those days of nearly forty years ago. On-line shopping has taken over when it comes to the run-of-the-mill stock and I will only use Maplin for stuff I can't get elsewhere or just good old fashioned convenience. Their range of stock has broadened to encompass all manner of electronic items including such things as toothbrushes! This is to the detriment of their stock of components - I may not like it but I do understand it.

If you need quantities of components (I wanted about half a dozen, 1Amp, automatic circuit breakers) it is back to mail order as the shops will only carry one or two in stock. They will order them for you but in today's world that is far too much bother. An order of £35 and over is delivered free of charge and it will usually arrive the next day if you order early enough. A flick through the catalogue revealed a few items that would be useful and their diverse range of items, I was bemoaning a few sentences ago, now has an advantage. I made my order up to £35.04 and pressed the 'BUY' key. a few clicks of the PayPal checkout and the deed was done, painlessly with very little effort. I hardly felt a thing as I was parted with my money - maybe that is the point...


Tool holder from scrap 

Amongst my order was a 12-piece, stainless steel, wax carver set that will be useful for plastic and plaster scribing as well as general detailing. These tools are supplied in a clear plastic clam-pack and I suppose I could have stored them in that. However, I prefer to have these sorts of tools to hand and without the hassle of fighting with the plastic packing. I managed to find a stout cardboard tube, from which I cut a short length and stuck it into a blind hole bored into a square of 12mm thick MDF with a 35mm diameter Forstner bit.  The upper arris of the MDF was chamfered at 45ยบ to finish it off neatly. I will probably apply a piece of non-slip mat to the bottom to make it more stable on the varnished bench top.

Ralph.

Monday, 23 April 2012

30 years ago today…


On 23rd April 1982 the ZX Spectrum home computer appeared on the market. It was the start of a battle for the emerging home computer market being fought by Spectrum creator Clive Sinclair and his arch rival Alan Sugar founder of Amstrad. Eventually Amstrad won and bought the Spectrum range in 1986. The Commodore 64 and the BBC Microcomputer were also in the fight and adding to the must have items of the 1980s.

All this new technology was the death nail in the already fragile ‘traditional toy’ market that had already seen the demise of the Airfix company (who at that time also owned several other household names such as Meccano).

Three decades on and we all accept home computers, as must have fittings in our homes (or you would not be reading this) and prices have levelled out. But the teenagers and early twenty year olds of the 1980s are now the returnees of today. This time around with disposable income and time to devote to the hobbies of their youth. Model railways and plastic modelling are going through resurgence at the moment. Things can only get better!

Ralph.

Wednesday, 4 April 2012

PASSED - A pair of controllers - Update

The controllers that were repaired yesterday passed a PAT test and are now ready to returned to their owners. There isn't usually much wrong with this sort of kit and the small amount of effort required to make each item safe is well worth the effort. It may seem like more rules and regulations for the sake of it but in this case I think it is justified. On testing some of my own equipment the process threw up a few issues that I was not aware of and was able to effect repairs before a problem occurred.

Two happy controllers!
Even without having your equipment tested electrically it makes good sense to visually inspect it regularly keeping an eye on cable restraints both at the plug end and the equipment end. Also check the cable for cuts and lumps and bumps and never join a cable with terminal blocks and insulating tape!

Ralph.

Tuesday, 3 April 2012

FAILED - A pair of controllers


If there is one sure-fire way to fall out with all your mates, it is to tell them that their electrical equipment has failed a Portable Appliance Test (PAT). Being a gluten for punishment I offered to do just this. The first thing to understand is that portable appliance testing is there to check that the appliance will remain safe under fault conditions. It is not about testing to see if the appliance is working properly. The usual retort, when the owner of a piece of equipment is on the receiving end of a red FAILED sticker is to state that it has been used for years and it works perfectly. Once the concept is explained, most owners are only too pleased to know there is a problem and will have the appliance repaired. This can be as simple as replacing a missing screw or fitting a complaint fuse. Sometimes it can be a bit more involved or even bizarre as the following will show...

Oh dear, failed stickers!
Last Saturday I was carrying out some PAT testing at my local Meccano club. Most of the equipment that passed the visual check passed with flying colours. There were a few dodgy looking extension leads that ended up being condemned for having damaged cables, socket and plugs or non-compliant plugs. Some had all four!

It was a lump of cardboard!
On the whole, the most common reason for failure was either non compliant-plugs or bad cable restraints. All of which are easily rectified. There were three items that I could not pass on the day one was a 110v American power supply that I had to bring back here to test - it passed - the other two were a different matter. 

One is an Orbit controller of relatively modern vintage. This looked good from the outside no problem there, all the case fixings were sound and there was no visible damage. The unit was fitted with an IEC lead connector so no issues with the cable. The problem was that something inside was loose. All modern transformer cases have to be user unserviceable, in other words riveted together. This meant I could not open the case on-site. There is a limit to how many tools I want to take out to a 'favour' job and as I didn't have the van with me, there was no backup outside!  So the unit came back to the workshop for further inspection. It could have been anything. there was no way I was going to even test this unit until I knew what was loose inside. After removing the pop rivets that held the case closed, I was amazed to find a piece of cardboard wrapped around the mains transformer.

The case is closed and fixed with pop rivets
What on earth it was supposed to be doing is beyond me. It did not need to be there as the high voltage terminals are all solder connections to parts that are fixed in position, therefore insulation is prided by 'air' (a physical separation held in place by mechanical means). The cardboard was removed and the screws that hold the transformer were sealed and marked not to be removed. This unit and its ICE lead can now be tested.


Old colours and this knot is the cable
restraint. That will have to go!
New cable and a cable tie used as a cable restraint will
need trimming before the case is closed
The other controller was an ancient Triang unit similar to one I had in my first train set over 50 years ago! This one was in a bit of a state. Screws missing, non-complaint plug and fuse, bad cable restraint and suspect, non-harmonised (wrong colour insulation) cable. On the bench, the case was opened and a new cable and restraint fitted. After a good blow out with the airline the case was reassembled using pop rivets. This unit too is now ready for testing.

Plugs 

It seems that we modellers hang on to transformers and controllers for years. Apart from obvious damage to cases and the power cable, plugs are the most frequent reason for failing the visual check. A modern, compliant plug has insulated live an neutral pins and is moulded with all the relevant approval logos and numbers as can be seen here on the left. The plug below, on the right is the old type without the insulated pins, secure fixing screw etc.  

 
Tomorrow we will see if the controllers pass the electrical tests and get nice green stickers!

Ralph.

Monday, 2 April 2012

I made it back!

The cable tower (today) standing at the Southern end of the system at North Greenwich. The poor guy in the yellow Jacket was fighting with a heavy yellow plastic hose trying to water the shrubs but the hose had other ideas. Who is going to be the first to build a model of the system?

Yes, after a dodgy start we made it all the way to Westfield, Stratford City - no its not a football team, its a shopping centre see HERE if you must. It did have a very well stocked Model Zone which was one bonus in a sea of shoes and handbags... with my Mum in tow, we still managed to get a sneak peek at what has been going on at North Greenwich today.

The cable tower is now up and they are cabling up ready for action. It won't be long now before the Cable car is up and running. There is a very good animated video showing an impression of how the completed system will look when completed HERE. I think we wore out my dear old Mum, she has not bent my ear for at least an hour! It may have something to do with the lasagne we made when we got in and, between the three of us, have now made a sizable dent in!

I will be in the workshop tomorrow so pop back and see what I have been up to... It will involve rivets! 

Ralph


Sunday, 1 April 2012

Finished!

Finished windmill - no a bad result.


By midnight on Friday we had built the windmill ready for the SELMEC meeting on Saturday. It did mean that the planned supper was sacrificed and the local Chinese take away got some unplanned business! Saturday was a real busy day. Pat tester, stickers and tools packed along with a few odd models it was off to the meeting. A good time was had by all and the PAT testing was a bit of an eye opener. Most things passed but some did not, and will need sorting out. I will post some pictures of the problems and how they are repaired in the next day or so.

We have my Mum staying with us for a few days so workshop time is down to a minimum but it does mean we get to waste a bit of time out and about. Tomorrow it looks like we may have to go... Please sit down... SHOPPING! Yes, it looks like yours truly is going to be dragged, screaming and shouting, to Westfied shopping centre in Stratford.

Meet my Mum, she is the one with the walking stick - no arguing today!
This may not be as bad as it sounds. There could be some eating out involved and we might get 'lost' on the tube and DLR and end up at some interesting places like Greenwich peninsular (You know, where The Dome, sorry, the O2 is). There is some interesting stuff going on there  involving big cranes and some heavy plant working on the Emirates Air Line. No it's not an aeroplane it's a new cable car. See HERE. I am sure we will find some other interesting stuff while we are charging around East London on our Oyster cards!

Ralph.