Friday, October 14, 2011

Flettner Ventilators - AV426 Retrofit

Flettner Spinning Ventilators were one of the more modern fittings used by the WAGR for attempting to create an airflow through the roofs of coaching stock to assist with cooling during the summer period. The Picture below shows two vents on top of the real AV426From a modelling point of view these ventilators are a very important part of producing a model which "looks the part" - in real life we only see these items from ground level, but with a model they are the first thing we see as we look down on our models from above.

Initially when I built a couple of coaches with these vents on the roof I opted for the easy and basic use of a slice of leftover Kadee coupler sprue which gave a good representation (as can be seen in the next picture) but that was all - I was happy with the result but I knew it could be better. After the show this year I started to produce the AZ kit (see elsewhere in blog) and decided it would be nice to be able to not only do the early version but also the later modernised versions which would need to have the Flettner Ventilators and lots of them - far too time consuming to make individually, and so I started down the path of producing a pattern for casting.


In S scale these vents are 3.75mm diameter and 2mm deep making them a very tiny and fiddly item to produce. After much cussing & time fiddling around, a pattern and mould was made enabling casting to begin.

And so I hereby present the WESTOZ MODELS - Flettner Ventilators.
The Picture above shows the vents on the roof of the AV dining car at the museum with the available 12pk of WESTOZ MODELS vents, and a much magnified view of the cast vent.


The view shows the bottom of the vent. Modellers need to gently sand the 'Top" of the casting to remove excess casting flash. This is best done using a fine sandpaper such as 400 wet and dry. "Care must be taken" to ensure an even sanding and not to heat up the vents with heat from fingers - as with any urethane casting they will bend with heat.


To show off these vents I figured I should retro fit one of my existing coaches and so AV426 was chosen - the pliers gotten out and the old vents twisted off the roof. Dont worry I cringed just as much as you probably did reading this, but it had to be done, even at the expense of potentially wrecking a perfectly good model. This next picture shows the old sprue vents removed from my AV dining car& the new Flettners in place and ready for paintingCast onto the bottom of the vent is a flat raising tab which will lift the vent just off the roof surface to give the impression of it not sitting flat on the roof - Place a small dob of glue on this tab an locate on coach roof - allow to dry and then paint. The above picture and the one below show the finished refit of AV426 with the Flettner Ventilators - Now to do the rest of my coaches!


As these vents were widely used on many different classes of coaches, hopefully they will make a very useful item for WAGR S scale modellers, enabling more coaches to be completed and "Look the Part" from above.

2 comments:

  1. Where do get West Oz models from

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  2. Are the WAGR flettners a standard size or type? Would they be similar to those used on the more modern DMU stock like the ADKs?

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