Point Operation
Using Servos
Electrical operation of the points was chosen because of the location of many of the points from the control panel. I also made the decision to use servos, for a several reasons -
- They are kinder to the points, being slower in operation
- They move at a prototypical speed
- Cost and operational reasons (for me)
Small servos these days can be had for as little as 1,50€ each, which fulfills the cost requirements. Even allowing for the fact that some form of servo controller is required, for me it was a better alternative than some of the 'slow-acting' point motors available.
Usefully, MERG do a Servo Controller (downside is that you have to make it), which will set up and control up to 12 servos - currently the cost is about 35€. Kits for single servo or 4 servos are also available, but with 16 points on the layout, two controllers made sense and simplified the wiring.
MERG also sell a useful set of 3D printed servo mounts for above or below board fixing, which works out at about 1€ per servo1 Add in the cost of micro-switches for frog polarity switching and a DPDT switch to trigger them and the cost is still way below that of several of the proprietary motors available.
Servos are also very reliable these days as well! So far the servos have been installed and operating for nearly five years and haven't given me any trouble at all. There is a little bit of 'chatter' around the layout when the control panel is powered up, but nothing during normal operation.
Changing the points is a nice quiet, calm affair and likely to to preserve them, rather than the 'slam' from a solenoid operation! I like the realistic movement of the blades as well.
The video below will give you some idea of the smooth operation. that can be acheived.
1 I realise that not everyone wants to construct their own servo controllers, but it's something I enjoy. Membership of MERG is also a requirement to be able to purchase these units. There are plenty of alternatives available, evident by scanning the ads in the model railway press!