CDU ?

Bill asked:
...I've followed ur link from the 3mil e'group to Melbridge Dock and on to 'point motors':
http://philsworkbench.blogspot.com/2009/01/point-motors.html

...Glad I did because it reminded me of reading what you have to say about Peco from a previous reading.

I'm getting reports from a few mates who have trouble with the PL-10/12/13 combo and even on the N gauge point! The complaint is unreliability to the point of no-go which is disappointing to hear. I've asked the question if they are using a CDU and the universal answer is no.

Tell me, was the use of a CDU your solution or did you just start out with a CDU and therefore sailed through these unreliability problems without ever realising there was a storm ahead- if you didn't, as so to speak... or do you feel your experience was down to something else?

I had to think quite long and hard about this and I think the answer dates from the mid 1980's when we built a layout called "The Cawood & Wistow Light Railway", a model of the line of the same name. It used PCB track and PECO motors and for a while the wiring was as per the PECO instructions which didn't include mention of any assistance. The idea was that you just attached the motor to a 16V AC output and used a probe and studs for switching. We had the same problems, points didn't reliably change and often just buzzed when we tried to switch them.

Introducing a CDU into the circuit solved most of these problems and has been part of any layout wiring plan since. That's why I had to ponder as it's so long ago since we tried not using one. For the money (Modelex heavy duty version, £6.95) you can't beat one.

Obviously you do need to check that the points aren't glued up, or have ballast in the blades but if that isn't the problem get a CDU. In fact, get one anyway.

Oh, and if you are using PECO points AND adaptor bases, take the over-centre spring out of the later, the motors aren't strong enough to move two springs and you only need one anyway.