We have just completed the new spur of track that goes across the pond via a small bridge and extends 15m through another tunnel of trees to join back onto the main track. The final work involved installing our new set of 30ft radius points from Maxitrack by the station. This means that a full journey (twice round using both routes) is 140m long.
There were concerns as to what the radius of the track actually was by the station where these points were to be located. But thanks to our method of marking various curves out on a board using what only can be described as a huge 30ft compass, then matching those measurements to points available, we managed to get the points to fit exactly.
I have just purchased the components to automate this set of points. This is an small actuator (the sort used to automate a garden gate) and a sprung mechanism to move the points allowing for then to be 'trailed'. Trailing a point means that you can go through the points safely from the opposite direction without changing them. As long as this mechanism works well i will also install one on the 10ft radius set by the pond. All the points will be operated from the signal box (next project) which will also include the operation of the signals and CCTV monitoring equipment.
The actuator is quite small meauring only 170mm long and 74mm wide but will shift 160 Lbs! The speed is about 10mm per second which is plenty fast enough for our needs. The actual movement needed is only about 25mm so the other 25mm of movement will be taken up in the damping springs to allow trialing of the points. The damping also allows for give if a stone etc. gets lodged in between the point blades. if this give wasn't built in, the power if the actuator would just bend the mechanism or point blades.
Actuator motors can be found on ebay for about £23.00 -very reasonable considering a pre-built unit from Cromer White (all be it including the point mechanism and beautifully built) is over £300!
In the diagram above you can see the actuator included in the home made mechanism to move the point leaver. The damping unit is home made from 7mm threaded rod, 90 degree angle brackets/ washers and Unitsrut ' zeberdies' (a galvanised flat nut with a spring pre attached). All the components are galvenised against the weather.
Although you can get them, the actuator is not IP rated as far as I know, meaning its not weather proof. So the finished unit will have to be in some sort of box. You can read more on IP ratings below. An IP rating is a code given to electrical items to let the user know what sort of water and /or dust proofing the item may have - or none at all in my case...
'Zeberdies' or sprung channel nuts as they may also be known, can be purchased from Orbital Fasteners in Watford, Herts. As I have mentioned before in my posts, Unistrut is a bit like grownups Meccano, it offers an amazing array of components to make just about anything. I have used it to make the bridge over the old pond and use it at work in the events industry to make all manor of support systems for audio visual equipment.
Some IP Ratings explained
Below you can read what some of the IP ratings mean although there are more. The numbers that follow 'IP' each have a specific meaning. The first indicates the degree of protection (of people) from moving parts, as well as the protection of enclosed equipment from foreign bodies. The second defines the protection level that the enclosure enjoys from various forms of moisture (drips, sprays, submersion etc).
IP65 Enclosure - IP rated as "dust tight" and protected against water projected from a nozzle.
IP66 Enclosure - IP rated as "dust tight" and protected against heavy seas or powerful jets of water.
IP 67 Enclosures - IP rated as "dust tight" and protected against immersion. for 30 minutes at depths 150mm - 1000mm
IP 68 Enclosures - IP rated as "dust tight" and protected against complete, continuous submersion in water.
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