Point actuators
Actuator installation assessment and testing
With Laurence being 'lasered' again, Geoff took over the mantle of actuator manufacture and the remainder of the base plates were drilled, ready for assembly.
In parallel, Stephen started to assess how the actuators would be fitted, as a combination of the existing point design and H&M actuator 'flexibility' had resulted in some awkward positions to be overcome. However, the first to be changed was on the new board, on a new point and no obstructions. A length of spring wire was bent to fit onto the actuator horn and the unit screwed into place. NB: Ordinary holes in the base plates might need to be elongated to allow for adjustment. However, in this instance, alignment was OK.
On the 6mm baseboard, it was quite noisy. The servo was stripped down and grease applied to the gears, which made some improvement. The other locations were on 1/2" chipboard, which might dull the sound further.
Testing with a railway controller threw up some issues with over-voltage and, it was suspected, the back EMF. A standard, adjustable power supply was fitted, and running at 3 volts, it was much better. Introducing a 10 ohm resistor worked a little better still. Some actuators will be operated in pairs, so different resistances can be applied to suit the positions.
All forward/reverse testing was with 4-hands swapping loose wires, so a simple reverse switch and power socket was made up to make it easier.
A useful and satisfactory start to the replacement procedure.
