they dont work

I'm in the process of building an exhibition layout with ten points, I wired these points via a CDU and after a bit of fiddling I got all ten points to function properly. But then I noticed that the Skaledale  Magna Goods Shed (brilliant building) would not fit into the area which I had planned for it, which meant I had to install another kickback siding in order to accommodate the goods Shed. Well I installed the siding and wired the new point and extra switch via the same CDU and thankfully they work perfectly, but now two of the points on the platform line which are crossover points and work together off the same switch for the loco to run round are not working, there is power getting to the points because they do click and move a little I have fiddled and fiddled but cant find the fault, anyone got any ideas and any suggestions would be welcome.:sad:

If you don't mind me asking, which point motors do you use, and how have you installed them ??

If the points are moving a little it will most probably be due to the fact the the CDU capacitor either can't handle the load or has not been given sufficient time to recharge.

hi, bike2steam, they are hornby point motors and passing conntact switches, and they are mounted below the points through a hole in the baseboard.

[user=1145]kentom44[/user] wrote:

hi, bike2steam, they are hornby point motors and passing conntact switches, and they are mounted below the points through a hole in the baseboard.

Is the throw of the point motor near enough perfectly parallel to the throw of the tie-bar ? Was the point motor installed central to the tie-bar throw, in other words, both point motor, and point tie-bar kept in central position with packing when installed?

 

Hi, bike2steam, thanks again for your help, as far as the points are concerned they worked perfectly prior to installing this new kickback siding, so yes the throw of the point motor and tie bar must have been parallel So I think my next step must be to disconnect  the new siding motor to see what happens.:sad:

[user=1145]kentom44[/user] wrote:

but now two of the points on the platform line which are crossover points and work together off the same switch for the loco to run round are not working, there is power getting to the points because they do click and move a little I have fiddled and fiddled but cant find the fault, anyone got any ideas and any suggestions would be welcome.:sad:

Hi Kendall,

From 10,000 kms away I still reckon your problem is the CDU does not have enough charge to fire two switches at the same time and that the new point is a red herring - try disconnecting one of the two points from the switch that activates the two motors and see if the other one works - if it does then that will be your problem.  I had a similar problem - two points using one CDU - worked well for a while and then suddenly didn't - never been able to explain why.

The other possibility might be that the crossover track has moved slightly when adding the new siding. Point motors are not very strong and rely upon free operation of the point before adding the motor. Check the point manually - if it is stiff in operation then it needs to be jiggled about until it is free in action.

I know Iansa uses Peco's widely on his operational layout.  I remember him saying it's important to check the resistance of Pecos as over time they tend to go off.

I'll bump this to his email.  He'll probably answer tomorrow as his machine is off at present.

Thank you all for your advice, I will now go off and try a few things and come back to you later

I was using a CDU and getting moderate results but when I decommissioned an HP printer [the old sort with a separate power transformer] I used this instead of the 16 volts a.c. supply from my power unit to drive my points. As it give 18 volts and is self-regulating [it always kicks out 18 volts, whether the load is large or small (think printer….printing, loading paper, i.e. variable loads)] it has performed perfectly with my Seeps, some in tandem.
I mention this only in passing as you may not have an old power unit, but I bet someone you know has, some where……
Doug

Max is right (again):lol:, if the ohms resistance gets below 3 it can cause problems with peco p-motors and I woud assume Hornby would be the same.
 If resistance gets below 2.5 it is nearly a short and p- motor needs to be changed

 How ever, I don't think this is the problem in this case.

 As has been said, I don't believe the CDU is delivering enough voltage to drive 2 point simultaniously.

 I have never used CDUs but have always used minimum of 18v AC 3amp power supply to my Peco p-motors and have very little trouble with points not changing even 2 in tandem as in cross overs.

Fot yrs my points have been op thru DCC system using Lenz LS150 accessory decoders and I still power them with 18vAC.

 Have not blow'n an LS150 yet, after about 8-9yrs.

 If powering points with normal op, not DCC, and not using CDUs always power point motors with AC voltage. Not DC.

 Peco p-motors will not op reliably  using 16v or less delivered at the motor.

 As I said, I would asume Hornby p-motors to be the same. 

 I am only speaking from my experience.

  Cheers

  Ian