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Friday 29 April 2016

Project 16 - West Field Pt.3

A View Along The Embankment 

The field on the left is created from two shades of green static grass (flock).

A View From The Wood Towards The Station

The railway passenger coach on the down line awaits the engine to back up to it :)

A View From Station Road Across The Embankment and Field To The Wood
Small trees and shrubs are Woodland Scenics.
Large trees are sprigs of Yarrow glued together.

To Part 19.

To Part 1.

Saturday 23 April 2016

Project 16 - West Field Pt.2

The white plaster surface was painted with green kiddies paint, its more like emerald green than grass green as that is what I had to hand. It is only to provide a background colour to the grass that is to be 'sown' in case it 'grows' a bit thin. There is a point of view that brown for soil would be better. I did paint the wood area in the corner brown as that would have bracken more so than grass under the tree canopy. I have placed a fence and some undergrowth in the corner temporarily.

I glued carpet underlay over the embankments, the old fashioned type that has a hair, jute, wool, string and anything else they care to put in to bulk it up. When dry it was very carefully ripped away to leave a very hairy surface like unkempt grass. The strands were raised further with a nail brush and trimmed with scissors and hair clippers to remove excess height.

An acrylic grass green spray paint quickly and effectively turned the hairs from brown to green, although I did not over do it to allow some brown to show through for a graduated colour.

The top of the embankment beyond the platform was sprayed with dilute PVA and barley coloured static grass applied with my home made applicator to give the appearance of long dry grass of late summer, whereas alongside the platform the grass has been occasionally cut by railway staff or their contractors.

This photo below of the embankment alongside Station Road shows the coarseness of the grass quite well.

To Part 18.

To Part 1.

Thursday 21 April 2016

Mainline 42 Warship Clunking Noise Fix & More

Bachmann used the 1970s Mainline Class 42 Warship body with a few extra details for its own Class 42 and added their own chassis, motor and bogies. Both models are now obsolete, being only available from the after market. The Backmann is about twice the price of the Mainline on Ebay so, with no prior knowledge of what I now know is an appalling motor and gearbox design, I opted for the cheaper Mainline version.

The Ebay seller declared it was untested so there can be no cause for complaint when I ran the locomotive and wondered what the strange clunking noise was. A search for information revealed many comments about the overall poor performance of this model and revealed the cause of the clunking noise.

If you are thinking of buying a Class 42 then take my and everyone else's advice and pay the extra for the Bachmann model. If you have a clunking Mainline version then read on for solutions.

Split Final (wheel axle) Gear

That is the cause of the clunk and if you are unlucky then both axle gears may be broken. To get to the gears the bottom plate of the bogie has to be prised off by inserting a small, flat screwdriver between the bogie body and end panel of the bogie bottom plate and gently prise apart and pull down to release it. This can be done without removing the bogie from the body. The wheel axles can then be pulled straight out.

There is a deep depression in the gear shown circled in the photo caused by the mould tool ejector when it pushed out the part from the mould. This introduces a significant weakness in that area so that under load a split can occur, shown by the white line. That is enough to cause mis-meshing between this and the adjacent gear. Worst case the gear might start slipping on the axle.

This is a common fault, Fortunately replacements can be purchased.

Ultrascale offer a brass replacement, You may need to replace both gears as the number of teeth is one less. This is the most expensive option and on a long lead time when I checked.

On eBay I found a close match sold as a pack of five and being inexpensive with fast delivery I purchased this.

Mainline gear spec: 16 teeth, 8.72mm diameter, 2mm axle.
eBay Seller firstclass4u208 spec: 16 teeth, 9mm diameter, 2 mm axle.

The faulty gear is a two tier arrangement but only the outer teeth are used. The replacement part is a single tier and the eBay model is much thicker. What you have to do is cut it down to the same thickness as the original, i.e. overall thickness of the two tiers, and file the tops of the teeth to bring it down close to the 8.72mm of the original.

To fit the gear first remove a wheel by griping both wheels with combination pliers and twist whilst pulling apart. Eventually one or both wheels should come off the axle. Slide off the old gear and press fit the new gear. I did this in the jaws of a vice with a metal tube over the axle that rested on the gear. As the vice jaws close it pushes on the tube which pushes the gear along the axle. Once on it is possible to slide it into position with finger pressure. It is important to position it so it is always in mesh. Test this with both wheels and the new gear on the axle. Check the sideways travel of the axle in relation to sideways travel of the adjacent gear. Also check the meshing is not too tight compared with the original (file more off the teeth if it is).

You may find the new gear rubs on the base plate because of a raised gear stopper (shown white boxed). You'll need to Dremel/grind that away if necessary.

Hot armature melting plastic

I was happy the new gear was doing its job but still found other performance issues, sometimes slow running on full speed or stalling. Eventually, the locomotive stopped but motor still running. Why? The spindle turns in a hole in the plastic body, not a proper bearing, and because of this the motor inherently runs hot causing the armature spindle to soften the plastic resulting in it moving out of true and the drive cog going out of mesh, let alone the coils snaring between the magnets causing the motor to lockup, and I'm sure all this lead to teeth being sheared off the centre large gear!

I fabricated a bearing from nylon sprue, opened out the spindle hole and glued the bearing in place. I only did this for one end as the other had not deformed. If you do this make sure the armature spindle spins freely in the bearing.

The gear with sheared teeth was potentially a show stopper. It is two tier 32/9 teeth, which is an unusual specification and none found in the market. The only solution it seemed was to scrap all this work and buy another warship for its motorised bogie. Even if a good one was found the chances are it will eventually fail too.

Some modellers have fitted the reliable Hornby Class 42 motorised bogie but I have cosmetic issues with it, like the brake blocks don't line up with the wheels .Others have fitted the body to a complete Bachmann chassis (May as well buy a complete Bachmann).

I decided to try and repair the missing teeth. Using nylon sprue again I fabricated an insert with file and razor saw and glued this into the gear (shown circled in the photo). Further fettling was required to ensure the two gears meshed freely.

To my surprise the repair held and I had a working locomotive again. Well almost, I find the locomotive needs to warm up to achieve full speed potential and even then its pulling capacity is only four passenger coaches *. I wonder if I should have fitted a bearing for the other end of the armature spindle? For now I have left as is but being concerned about a hot motor I glued on a heatsink designed for an integrated circuit (Maplin RN70).

* Postscript. The cause of this was the bearing axle hole being very slightly off centre placing the axle under stress, which then wore away the nylon making the hole larger and eventually going out of mesh. I replaced the nylon with a brass bearing fabricated from a brass screw shank and took great care to centralise its axle hole acurately. Loco now runs from cold to full speed without faltering and can handle longer trains. I also removed the heatsink as the motor does not get so hot.

One other thing to be aware of is the carbon brush springs. If you need to replace these then make sure they are not too long as the extra pressure on the brushes causes the motor to stop turning. Peters Spares sell replacement brushes and springs but their springs are too long in my opinion.

I'm not hopeful that what I have is a long term solution. I will be on the lookout for a good spare motorised bogie.

By the way, the extra material costs I incurred still makes my purchase far cheaper than a Bachmann.

It is a great looking model don't you think, evocative of the mid 1960s. This one, D824 'Highflyer', is reputed to be the first of its class to run on the Southern main line after the Western took over in 1963.

Friday 15 April 2016

Project 16 - West Field Pt.1

This is the actual field to the North West of the station that is to be modelled. Note the embankment alongside the platform and the hedge line in the distance, which is alongside a track called Green Lane. I searched but could not find a local name for the field itself so, I'm calling it West Field.

And this is the beginnings of the field on the model.

It is only about 2.5% the area of the real field and yet it occupies about 25% of my Misterton model railway! That is a lot of real estate in modelling terms to dedicate to grassland. I do like to see a model railway set in the context of its surrounds but that amount of vacant area is a step too far I feel. I considered bringing the hedgerow of Green Lane forward to the back edge of my field but Station Road whilst inclining down has not yet reached the level of Green Lane.

Previously in this area of the model was a wheat field with an overgrown fence line boundary to a wood of mature trees. I plan to place the previous fence line and some of the trees into the top left corner of my field, not along the entire length but about half way to give the impression that the field continues beyond the model This arrangement should add interest and be a nice back drop.

The landscape is made from polystyrene foam packaging sculptured with a hot wire cutter and the gaps between blocks covered in plaster-of-Paris bandage. The lot was then covered in textured ceiling plaster, mainly to cover holes appearing in the bandage fabric.

The non scenic, removable bridging baseboard is visible in the foreground. Track on this is Peco streamline code 75 rather than my own fabricated sleepers on Peco code 75 flat bottom rail used on the scenic section.

To Part 17.

To Part 1.

Saturday 9 April 2016

Project 16 - Signal Box

Earlier I mentioned that a new Signal Box was needed because the previous one was too tall for platform mounting. This is it - a LSWR Type 1 from Crewkerne. At Crewkerne it lasted until October 1960 when it was replaced with an austere rectangular box (literally) that was placed off the platform. My model has the original open wooden steps but sometime before the 1960s the staircase had been replaced with brick steps.

How the model was made

A photograph showing the front of Crewkerne box was opened in my graphic editing Application and scaled to dimensions obtained from a scale plan of Witley box shown in G. Pryers book 'A Pictorial Record of Southern Signals'.

Decorative layers where then drawn and overlaid on the photograph to create individual parts, for example, window frames and valance. With regard to the sides and rear it was a case of finding other photographs of those sides. No photograph of Crewkerne's rear was found, which was a shame because side views gave a tantalising glimpse of a lean-to brick built structure at the rear. Fortunately, photographs of similar boxes exist giving good views of the structure. Most notably, Chard Junction and Crediton.

The parts were ink jet printed on sticky back paper, stuck to greyboard, cut out and assembled. I am using Epson Durabrite Ultra ink that is specified as having excellent colour retention over time and is water resistant. Some of my models printed this way are over five years old and look as good as new.

Now, that is just an overview of what is a complex and time consuming process to produce a detailed three dimensional model comprising nearly 90 parts. It even has interior decor and shaped gutters! The only parts that are not paper or greyboard are acetate window glass and 3D printed plastic down pipes. Later I may add furniture and lever frame etc. to the inside.

The footbridge is a kit bashed Heljan model to make it look like Axminster. Of course, this is not correct for Crewkerne. It had a concrete footbridge in front of the road bridge. I preferred the look of Axminsters, which is the reason why my model station is not called Crewkerne. It is not an exact copy.

Monday 4 April 2016

Project 16 - Down Siding

The siding running beside the down platform is not a platform bay but serves a cattle dock instead. It is based closely on the arrangement at Crewkerne. There is scope to extend it another six inches but I'll wait and see how much rail I have left over from laying all the sidings.

The head shunt for this siding has also been added, which needed an extension added to the bridging baseboard to support it.

The rail in the sidings is Bullhead whereas on the mainline is Flat Bottom. This reflects what was going on in the 1960s when rail was in the process of being changed from bullhead to flat bottom for maintenance efficiency and cost savings.
I feel I have made a 'rod for my own back' by deciding to make my own sleepers because what amounts to just six feet of track took about 3 days to lay. Why? Because half the time went on  printing, painting and threading sleepers onto the rail. The rest of the time was in laying the track, making off the ends that span the baseboards, wiring in the resulting dead sections and adding the small extension to the bridging baseboard.

The 3D printed sleepers are made in pairs with integrated chairs and oak keys. The quality of the 3D print is variable and does not stand close scrutiny but at normal viewing distance the track is more authentic looking than off the shelf stuff.

This unkind close up photo below shows the finished result. I failed to print integrated fish plates so am using some old Colin Waite brass etch stock. These are quite nifty because they have a clip on arrangement that does not require solder or glue. No longer available in the market but Brassmasters.co.uk have something similar - not sure if they clip on.

That round black end to the middle sleeper is a nail to hold the track in place. I explained this method in an earlier Post. By the way, the nail is not so noticeable once the ballast is laid around.

To Part 15.

To Part 1.
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