Katie from Scratch Part 4

 

This charts the progress from running Katie as a working chassis to completing the loco from the 4 kits supplied by Roundhouse, including installation of radio control.  Though I have yet to apply name-plates and a number to Katie, she is now fully operational under radio control.

 

I must apologise for the delay in completing this saga; this was due to the wait I had while Brian Jones Engineering waited for a new batch of Hitec Zebra radio controls was supplied, of which more later.

 

Re-Painting

 

I have to confess I made a complete horlicks of the paint job – mainly the cream in the cab interior, so I stripped the cab/saddle tank unit back to the metal with paint stripper and started again.  Etch primer and undercoat went on OK but Precision Paints had run out of aerosols of LNER Green so I had to make do with a tin of paint.   This has gone on OK but unfortunately the dusty state of my garage has meant that the finish is not up to Rolls Royce standards by a long chalk.  However, when I get my round tuit I’ll buff it up with car polish.

 

Running In

 

I started using Katie with the manual reverser quadrant/lever unit and the manual regulator, both supplied as bolt-on items, reverser as part of the chassis kit and regulator as part of the boiler kit.  The loco had very stiff motion to start with but after a few hours running has vastly improved – this has more to do with the excellent design than my brilliant engineering I have to say.  Because of the initial stiffness, when I ordered the radio kit I specified a heavy-duty servo for the reverser.  In fact this proved completely unnecessary after a few hours of running in.

 

 

I had a fair few heart-stopping moments until I discovered that a retaining bolt on the read nearside wheel had worked loose, allowing the timing to slip.  A sharp tap with a hammer to restore the wheel to the axle quartering and firm application of a large screwdriver on the retaining bolt sorted this out, since when the noise from the motion has all but disappeared.  The loco pulls strongly in both directions, and has a fair and equal turn of speed forwards or backwards – quite capable of leaving the rails on an R3 bend if you really try!  The burner is much quieter than Edrig’s although Katie’s chuff is quieter too.  In fact Katie behaves like a good ‘un.

 

 

Fitting Radio Control

 

This took me the best part of a day, including domestic interruptions – about 4 hours in all, allowing for dropping irreplaceable nuts and bolts on the garage floor and other irritations.  I had to get the broom out at one stage, fortunately successfully.

 

 

 

The radio control adaptor kit consists of:

 

  • a set of pillars, bolts etc to mount radio servo for reverser
  • a bracket (previously soldered into place on the cab floor) for the regulator servo
  • a replacement connector arm from the server to the Walschaerts linkage
  • a new regulator valve and linking parts to the regulator servo
  • battery container that fits in the roof
  • a “box lid” fitting that goes between the frames under the cab and contains the radio control main unit and ancillary bits
  • replacement battery holder and mounting unit.
  • A false sliding cab roof panel, which is connected to the aerial and held in place with supplied sticky fixer pads.

 

The radio control itself consists of

 

  • Hitec Zebra radio control
  • Qty 2 micro servos (not mini-servos, as they won’t fit).  I specified one as a heavy duty version, for the reversing linkage, but as explained above this isn’t necessary – standard is fine.
  • Two-channel smoother, of which more later.

 

Barry Jones, who specialises in radio control for all sorts of garden railway stuff, was most helpful, but he is a one-man band and you have to be patient if his supplier fails to deliver.  I waited nearly 3 months from ordering to delivery, but this is a one-off and it was worth the wait in the circumstances, and my going off on holiday caused part of the delay.

 

4 x “AA” size batteries are needed for the loco and 6 for the control unit.  You have to cut off the battery box supplied by Hitec and substitute the lead and box supplied by Roundhouse.  This is because the Hitec one is in a “2 layers of 2 batteries per layer” configuration whereas the Roundhouse one is a “4 side by side” arrangement, and fits in a bolt-on housing on the underside of the cab roof. This entails soldering the Hitec plug onto the Roundhouse cable and covering each join with the supplied heat-shrink rubber insulation sleeve.  Not difficult but I thought you ought to know.

 

There are 2 star washers to fit, to enable the connecting arms between the servos and what they control to be secured on a pivoting thingy to which connecting arms are attached.  I found it easiest to use my Accucraft Edrig’s spinner (like a jeweller’s screwdriver but with a small plug spanner in the end instead of a screwdriver blade).  This fits over the star washer and a sharp tap with a light hammer makes sure it goes into onto the pin cleanly.

 

You have to trim the servo connector arms with wire snips and bend the regulator arm to ensure that servo and reverser or regulator work in the same plane.  Also, you have to make sure that the servo arms are the appropriate size and shape to do the job they have to do in the space available.  This involves cutting bits off and enlarging existing holes – a job for the trusty Dremel.

 

The radio receiver and various connectors live in the box under the cab and cable ties are supplied to keep wires under control.  The reverser servo plugs into Channel 1 and the regulator into Channel 2.

 

The rest of the kit is bolt-on, and the process is largely obvious.

 

To make adjustments, you follow the Roundhouse spec of the servo arm being 8mm from centre of turning circle to connector arm.  For the regulator, the servo arm should be as long as possible, to give the most regulator movement.

 

The final job is to solder a contact tab on the “sunshine roof” panel to the end of the aerial lead (which do not shorten if you want the radio control to work!).  I tidied up the aerial by using a piece of garden wire to make a “sheaf”; I did the same for the battery lead with no obvious ill effects.

 

Switch on the radio control unit and establish movement.  Ensure the loco reversing gear is in neutral and the regulator is closed then tighten the appropriate screws.  The reversing gear will move sufficiently to change direction but not through the whole length of the curved drop-link.  The regulator works through about 30-45 degrees only, so you have to adjust it so that you can achieve smooth starts and stops – a trial and error job.  (If you set too high, your engine will take flight at a Radius 3 bend!)  I set mine so that the engine just will set off without operating the regulator control – like a full size engine does using the expansion of steam already in the cylinders. Then you add regulator as necessary to maintain your chosen speed.

 

The Radio Controller

 

The Hitec Zebra is a 3-channel device, originally intended for model aircraft.  Channel 1 is operated by a the right-hand joystick, which operates in an east-west plane and controls the reverser.  The Channel 2 joystick  is on the left and works in the north-south plane.  There is a small slider switch to the right of the Channel 2 joystick that can be set to bias it to return to the “off” position instead of the centre; the Channel 1 stick doesn’t have this.  Both have trimmer tabs that you can use to let the engine run without your intervention if you wish.

 

The third channel is controlled by a trimmer tab on the top of the casing and would be used for controlling a whistle or steam-cocks.  I don’t use this.

 

Fitting a Smoother

 

In addition to the radio control I also fitted a smoother to the system.  This is a cunning piece of electronics on a board the size of a postage stamp that slows the signals from the radio receiver on the engine to the servos, and this has two effects: (a) it gets rid of the “rusty bolt” interference from metal greenhouse frames, French windows, washing lines and bird-feeder poles, and (b) by serendipity, it makes the engine’s responses to signal inputs slower and smoother, so that the engine’s reactions are truer to life.

 

 

Operation

 

It’s only when you have got the whole engine working that you understand just how neatly it’s been designed.  It heats up quickly but quietly, and you can hear its exhaust beat.  It runs slowly and stops where you want it.  With lots of steam pressure and just a little regulator you can stop it from running away downhill.

 

 

Yes it’s messy.  Yes it takes 10 minutes to get started and only runs for a further 30 before you have to refill.  Yes butane firing is a pig on a cold day (use propane mix).  But it’s FUN and the experience (he says, having spent a day on a driving and firing course, on a BR Class 5 4-6-0) is a lot more prototypical than my old Hornby Dublo BR Class 4 2-6-4T!

 

Was It Worth It?

 

In a word, yes.  However… if you are a new boy to live steam trains and just want a really nice reliable steamer, go and buy one ready-built, because by the time you’ve paid for the kits, paint, tools, and radio control you will have spent nearly as much anyway, and the ready-made one will hold its value better.

 

What justified it for me was the education in simple engineering that a lifetime’s driving a desk had deprived me of, and the proof to myself that I could actually do it.  Occasionally it was scary – like when I did some serious and untutored soldering for the first time in my life.  On the other hand, to work out a way of testing the chassis using a car tyre pump and seeing the valve gear actually move for the first time was one of those golden moments you never forget.   Modelling for me is like dancing elephants – it’s not that I did it well but that I did it at all!  Clearly Bredebahn’s little blue pills worked…

 

What Next

 

My first thought was that a small green 0-4-0 saddle tank should be called Percy, but perhaps, in view of my Geordie origins, I should be suitably obsequious and call it after a Northumbrian aristocrat – Lord Percy.  My ma-in-law suggested that I should call Edrig  Lady Muck;  I quickly discarded the idea of calling Katie the Good Eigg…

 

Then I thought again and remembered that the first of Gresley’s A4s were called Silver Link, Quicksilver, Silver Fox and Silver King.  I have two green engines, so what about calling them Green Something-or-Other.  A few names that came to mind were:

 

Green Goddess

Green Dragon

Greenfly

Greengage

Greene King

 

Anybody got any better ideas? Then please feel free to share them with me on the G Scale Mad Forum.

 

Richard Stamp

3 July 2006