When I first built Fisherton Sarum I made the decision to use SEEP solenoid point motors to control the turnouts, this was partly due to being familiar with solenoid motors at the time and partially due to cost. In hindsight from both a visual and reliability perspective a mistake. It has become apparent after a number of exhibitions that reliability of the SEEP motors is questionable, even when used with a Capacitor Discharge Unit (CDU), and most frustrating issue has been the inconsistent operation of the built in microswitch.

Originally I used the built in switch of the The SEEP PM1 motor for changing the turnout frog polarity and had glued a Peco PL-13 Accessory switch to the underside of the motor to provide switching for point direction indications on the control panel. As time has passed where the built in switch has proved inconstant or unreliable I have swapped the duty of the two switches over so that the Peco Accessory switch is doing the more critical role of switching the frog polarity.

I have now decided to replace all the point motors with the slow acting type and have chosen the DCC Concepts Cobalt slow acting motor (note I have not gone DCC control, I am still of the analogue camp). I choose this over the other slow acting motors on the market due to it being slightly smaller than its competition, recommendations from other users and experienced gained with them on Ashland, one of the Hornby Magazine layouts I helped build.

Installation of the motors on the whole is quite simple with the exception of one location where the motor needed to be installed to the side (where I plan to keep the unpowered Seep motor in place as part of the crank arrangement).

I am utilising the existing wiring and control panel push buttons, but as the Cobalts require a polarity change and a constant supply, I have turned once again to my friend, fellow Fisherton Sarum operator and electronics wizard GWMark of this parish who is building for me some cleaver circuitry to take the push button inputs to and turn it into the constant feed required by the motor. Being operated from a 12VDC supply I am retaining a diode matrix system to operate a number of motors from one button when required such as on the ladder of turnouts in front of the shed.

This weekend has seen the first 4 motors (6 to go) changed and wired up.

This is an extract of my own blog at www.grahammuz.com and the full entry can be read here.