Monday, 29 February 2016

NSWGR Catch Point Indicator Instructions


13 May 2016

  • Clearing holes of waxy support material add and instructions not to use ACC Super Glue to attach the small 'donut' shaped retainer on the operating shaft added.

17 March 2016

  • Cleaning instructions added.

Use on the Prototype
Catch points are to be found where a siding connects to the main line. It is best to check some specific station layout for locations which can be found on the Track and Signal Diagrams of the NSWGR such as those available from the Australian Railway Historical Society (ARHS). The catch point is located just short of the connection to the main line and is connected to the point such that when the point if to the main the catch point will put a runaway wagon into the dirt, hopefully not then fouling the main.

The catch point has an indicator which is a small ground signal with a square rotating section at the top. This section rotates through 90 degrees to show an arrow for clear to proceed out of the siding onto the main or a red light.

Other Required Items
HO -  0.015” Tichy Train Group Phosphor Bronze wire (Part No. #1102 - 12 x 200mm lengths in a pack).

7mm Scale - 0.032” Tichy Train Group Phosphor Bronze wire (Part No. #1105 - 12 x 200mm lengths in a pack).
I sourced the Tichy Train Group products from Model Railroad Craftsman at Blacktown, NSW but I am sure there are other sources in Australia.


The Frosted Ultra Detail print
should be rinsed a couple of times for 30 seconds or so in acetone and allowed to dry. The second rinse should be new acetone. This is to remove a light vegetable oil (I believe) used in cleaning away the waxy support material required by the printing process. Where the support material was contacting the print a whitish effect will be seen. Once washed in acetone the print will be OK for gluing and painting.

It is best to try to paint the components while still on the sprue but some of the box frame can be removed with transistor nippers for better access.

Brush painting is best if the indicator is to be lit with a LED. If the lamp lens and the square indicator arrows and round aspects are covered in whitish support material from the printing process then carefully scrape this away as much as possible down to the acrylic. Some clear lacquer or a small drop of super glue can help to make these clear although the arrows are to be white anyway. The small round aspects are to be clear red which can be achieved by using Tamiya X-27 Red Clear
Remove the various components with a pair of transistor nippers held against the sprue. A small amount of pressure will clip the part cleanly from the sprue.

The main body of the indicator has a peg protruding from the base and this is to be located in a hole drilled into a sleeper. If this hole is drilled through the layout base board then a Warm White LED can be inserted from below to light the indicator. Two sleeper extensions are supplied as well as a short piece of sleeper that was either parallel or at right angles to the running rail. The catch point indictor can be mounted on either side depending on location, clearances, etc.
The operating lever is to be inserted through the body of the indicator and the small donut shaped piece is slipped onto the end of the shaft to retain the crank in position and allowing the crank to move freely. The hole through the body of the indicator for the operating shaft may need to be reamed with a 1mm drill to clean out any remaining waxy support material from the printing. The  very small 'donut' part on the sprue projecting form the rear of the main body will need to be reamed slightly to fit the shaft. DO NOT GLUE YET AND WHEN YOU DO PLEASE ONLY USE WHITE GLUE - NOT ACC SUPER GLUE!.

The square indication part is to be slipped into the round topped peg at the top of the indicator body with the operating loop going onto the crank. The lamp can then be fitted by aligning then flat of the peg with the flat in the hole of the lamp base. It can be very difficult to see the flat on the HO model lamp, it is opposite the sprue attachment point, the flat goes to the operating crank end of the main body. Push down gently and the lamp will hold the square indicator part in place allowing the square indicator to turn when the crank is moved.

If the Catch Point Indicator is to be made to operate then the operating lever is to be connected to the working blade of the catch point. The hole in the lower portion of the catch point lever is 0.4mm (HO) or 0.8mm (7mm Scale). The hole may need to be reamed with the correct size drill to clear waxy support material or paint. Make a 90 degree bend on the end of a length of phosphor bronze wire (0.015” Tichy Train Group for HO or – 0.032” Tichy Train Group for 7mm Scale) and insert it into the hole in the operating lever from the rear so that it will be trapped and won’t come out during operation. The operating rod is to be threaded under the running rail and soldered to the catch point blade making sure that the indicator is in the correct position to show the direction of the blade.

I have a horizontal adjustable point throw mechanism on my Signals Branch Shapeways Shop that can be used either under the baseboard or above it to operate and adjust the throw of the catch point blade and hence the catch point indicator.

This mechanism can be thrown by your preferred method, servo, point motor, wire in tube, or even with linen thread, fishing line or similar through screw eyelets with a lead fishing sinker attached below the short arm on the opposite side of the mechanism crank as a counterweight.
Please note that the following photos showing how the indicator is painted are of a 7mm Scale pilot model.

The NSWGR Catch Point plan is available on this Signals Branch Blog as a reference.

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