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Tuesday 28 January 2020

Project 20 - 0 Gauge Layout - Part 4

This is the third time I have scratch built turnouts. Previously I made turnouts for 00 and EM gauge layouts. Now it is the turn of 0 gauge. I am making my own to save expense. The cost works out to be about £10 (using some heavily discounted products off eBay) whereas proprietary r-t-r turnouts are about £50.

The parts that were troublesome for me to make in the past were the switch blades, to achieve good electrical contact with the stock rails and effective switch blade movement. The former was a problem because I do not use a direct frog electrical feed, which would require the complexity of an electrical switch to supply the correct polarity (usually automatically operated by a point motor). I need the switch blade to provide a reliable frog feed with the correct polarity when it touches the live stock rail.

I had already decided operation would be manual for this small layout and I wanted control to be my means of a lever alongside the turnout similar to the prototype.

I proceeded with trepidation, not really having solutions at the outset for the above. But, along the way I came up with reliable designs for those parts.

The fundamental parts for the turnout are:
  • 3mm plywood sleepers stained a dark oak.
  • Peco chairs and slide chairs.
  • Peco code 124 rail
  • Fabricated brass plate foundation for the frog and closure rail assembly.
The sleepers were lightly glued at the ends to a Peco paper template. The template peeled away after completion.

The rails were cut and formed using the template as a guide and the chairs slid over. Each chair was glued to the sleepers. Now, I found MEK liquid did not work and superglue was dodgy (Peco advises pins). I used 'tacky white glue' that claims to stick virtually anything. It did work but needs a long drying time. Some chairs that are under stress came adrift and were reinforced with superglue.

The only gauges I used to set the rails was a vernier calliper set to 32 mm and a 1.75 mm drill shank to set the check rails.

And so to the switch blades.

I made the switch blade and closure rail to be one piece (usually they are separate and hinged with a rail joiner) and soldered it to a brass foundation plate together with the frog. Thus, the whole lot is electrically joined. To aid movement I cut nicks in the bottom flange of the rail at the hinge point.

To set the gap between the two blades I used stretcher bars, like the prototype. The bars need to be stiff. I used pieces of EM gauge rail I had in stock. The style of the bars is not exactly as the prototype but they are in the correct place and look the part.

Needless to say electrical contact between switch blade and stock rail was unreliable. I spent a long time thinking of a solution and nearly reverted to a separate electrical switch until I had a eureka moment.

Taking some springy phosphor bronze strip I set it in the baseboard and in line with the open switch blade such that the blade pushes into it slightly for a good contact when 'on' (top blade in photo above). Each contact is wired to the opposite live stock rail beneath the baseboard. The position of the contact must be checked to avoid touching the wheel of a passing loco when in the 'off' position (bottom contact in photo above).

The manual lever control of the switch blades is quite novel, I think. I believe the prototype uses a sprung mechanism such that the lever is pulled and released in only one direction for each movement of the blades. I could not see a way of doing that so my lever is pulled one way and then the other to switch directions.

Looking at how the Peco 00 gauge mechanism works I adopted the same sprung method but, offset it from the turnout.

I 3D printed a sliding tie bar and housing for a Peco 00 gauge spring taken from a broken turnout. The tie bar has a 1mm wire through the middle that locates in a loop fixed to the nearest switch blade. The other end is upturned to fit into an angle crank.

A platform with a slot holds the lever that pivots in an integral bracket. The bottom of the lever locates in the same angle crank beneath the platform.

The platform and crank fit over the tie bar rod and is fixed to the sleepers either side.
The 00 gauge spring gives sufficient movement to hold the switch blade against the stock rail.

To Part 5.

To Part 1.

Tuesday 21 January 2020

Project 20 - 0 Gauge Layout - Part 3

Straight track is made from PECO code 124 Bullhead rail and home made 3D printed sleepers with integral chairs. The sleepers are created in blocks of four to span a 60 foot track section.

These photos do not show chair detail well due to the black colouration. Suffice to say that with an 0.2mm print layer the stratification is noticeable resulting in a crude finish compared to proprietary injection moulded items. Once installed on the layout the track will be weathered in lighter colours, which will show the chairs better. I am guessing the crude finish will not be too noticeable from normal viewing distance. Interesting to note that whilst 0 gauge is 1.75 larger than 00 there are still small parts with details that are barely noticeable.

The integral wooden keys deformed significantly during print. This was overcome by extending the key to give a good print run with a vertical support at the end to stop droop. The support and extended key was then cut away as shown by the far right chair.

Note that the plastic layering on the sleepers gives a wood grain effect.

At each end of the 60' section the sleepers are spaced as the prototype. I decided not to cut the yard of PECO rail at scale 60'. If clickety click sound of wheels  passing over the 'join' is wanted then a nick could be cut in the top of the rail.

To Part 4.

To Part 1

Wednesday 15 January 2020

Project 20 - 0 Gauge Layout - Part 2

The layout will be a water side setting. I considered a harbour and canal but am now favouring a tidal river. The track plan requires six turnouts (four Y and two LH). The key element is the passing loop in the middle, which enhances operation by enabling the train to propel wagons from either end within the scene.

Five of the turnouts will be buried in a tarmac surface. Proprietary, fully sleepered turnouts would be an over kill here. Cost savings should be possible if a make the buried turnouts as I only need the rail with a stripped down track base made from wood or plastic. With this in mind I also decided to fabricate the wooden sleepered track of the entry turnout and branch line. Making the sleepered turnout is far less expensive than using a proprietary item but cost savings for a DIY straight track are insignificant and only worth considering if either you have cosmetic issues with proprietary track or enjoy making your own.

I obtained turnout templates from PECO and TIMBERTRACKS. The latter may be more prototypical but they are longer than PECO making the short sidings far to short. I settled on the PECO templates. The shortest siding is about 40cm long. This is sufficient for holding either two wagons or, one wagon and a tank engine without encroaching on the turnout.

To Part 3.

To Part 1.

Wednesday 8 January 2020

Project 20 - 0 Gauge Layout - Part 1

I mentioned before that the inspiration for my foray into 0 gauge modelling was seeing 'Arun Quay' . The layout demonstrated that an authentic scene with operating interest can be created in a small space using 0 gauge (7mm fine scale).

Having made 8 wagons and set them out in a line with my Terrier loco on top of our upright piano they spanned the entire 1.4m length. It was then that I realised even a small freight train still demands space. This lead me to ponder a garden layout instead of a small indoor layout.

I could visualise a dumbbell layout circling the tree, snaking through the flower border passing the rear of the patio and turning back on itself through the far corner border-  a run of about 48 feet each way. The land slopes a bit in the flower border so the track bed would be a raised platform through the middle. I roughly calculated the cost of track and trackbed to be around £500. Then I thought, does it give value just watching a train going round and round since I am not interested in making a landscape with scale buildings etc. in an over scale environment.

My thoughts returned to a small indoor shunting layout like Arun Quay. I studied a variety of tack plans but nothing came close to the operational potential afforded by the Arun Quay plan. I make no apology for basing my plan on that with a few tweaks.

First job was to make the scenic baseboards, which was quick using two insulating foam boards 1.2m x 0.45m x 50mm from Wickes. The sides were covered in eighth inch hardboard for protection and these extended below by about 20mm to accommodate D type connectors and wiring- deep enough  to conceal SEEP point motors too, though I don't plan to motorise turnouts.

I used 'No More Nails' glue to fix the hardboard panels to the foam but found it to give a weak bond. It holds OK but would not take much effort to break the seal resulting in the panels coming away with chunks of foam. For added strength I glued quarter inch wood blocks into the corner joins of the hardboard.

The two baseboards join together by means of butt hinges with removable hinge pins.

A fiddle yard will be constructed later that will connect to the scenic boards.

To Part 2.
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