Model Railway Question (points)

Heya everyone .

Dounno if anyone would be able to help me out here but will oo guage peco point motors work with 12V ? or will they only fully throw the point at around 16 to 18V ?

I have tried it on 12V but they seem to get stuck on the first 2 or 3MM but once past that point , they seem to throw ok ....So is it just a lack of power and id need to look into buying a PSU along with a CDU ?

Cheers
Mitchell #-o

 

Try using a CDU. Capacitor Discharge Unit. That provides the 16-18V to throw the arm over.

 

Thanks

 

Definitely use a CDU, else your point motors will be permanently live... and hence the motor will wear out faster, you can increase their life span 100 fold !

 

Sorry , Re reading my orignal post , it makes it look like i keep a constant power surply to the point motors .

I used a power transformer to quickly brush the power to the motors but they wouldnt throw ...But after thinking about it and seeing the replys here . it seems that the extra 4 to 5 V is whats needed to throw the motor .

Thanks for the replys.

 

The use of the Capaciter Discharge Unit (CDU) works at 12-16 volts DC, what it does is stores up energy and releases it in one bigger "lump", compared to a trickle from what you would get from just putting 16 Volts DC staight across the point motor.

The other issue with using a CDU is that you want to use a "passing contact" switch (Hornby R044). This is a switch that only stays live for a fraction of a second, but this is long enough for a CDU to release its "lump" of energy to the point motor. If you were to supply a continuous supply to the point motor it would burn out the solinoid. Care needs to be taken when wiring the CDU as you can kill it by wiring it the wrong way round - on the Gaugemaster unit (£11.50 and worth every penny) I have used it has clear instructions about how the unit needs to be installed - not complicated but worth while to save the purchase of a replacement.

I attach the Peco PL10 units directly to the points using the tabs to locate and secure to the slots in the point sleepers. This method ensures the point motor pin lines up and can have a direct drive to the tie bar on the point, thus maximising the force.

The final trick which I use is to reduce the spring tension on the peco points. This is done by gently opening up the legs on the metal plate which holds the spring in place and sliding it back until the spring requires less force to throw it over center. The legs are then pinched back into position to secure the spring at its desired tension. Care must be taken when doing this to ensure there is still enough spring to hold the points in the desired position once thrown and also not to open the legs up so much that the plate comes off and the spring pops out never to be seen again!

With this set up I am able to throw 12 points at a time from a single discharge of the CDU.

 

Instead of the R044 you may want to consider a "single pole single throw centre off switch", or a "Push to Make" switch.
Gaugemaster sell these (cheaper still if in bulk).

They are small switches, somewhat cheaper than Hornbys R044, but they can be embedded into your own signal box track layout board (if you want to go that far). Push to make switches can be had for about 30p.

I previously used a combination of a single pole single throw centre off switch, and a Single Pole On / Off Switch to make track sections live (or Double Pole, Double Throw if switching between 2 controllers) after throwing the point (If using electrofrog points).

These whilst cheaper require soldering to the connections, where as the R044 is a wire plug in connection.

 

Thanks alot for both the posts , Makes alot more sence

 

The other method is to use a "probe and stud" method, where you make the curcuit by touching a live probe to a stud on a mimic board.

This is slightly crude and has an eliment of danger (keeps you on your toes!) but I find it is quicker to use and far cheaper.

You do need to know what you are doing with this method and I would not suggest it to anyone who is expecting juniors to run the layout.

As was mentioned if you are using electro frog points you need to allow for polarity switching and the best thing is to read some books on the subject as there are many different ways this can be done and everyone seems to do it differently.

On a slightly different subject, I am currently changing the layout of my fiddle yard and looking at a diode matrix method (using diodes to route the electricity to stop it flowing to point motors where the charge is not required) of setting the points to allow route selection, I have come up with a highly complex (and highly expensive) way of doing it, but was wondering if anyone had any information on this subject so that I did not end up over complicating it?

 

I see no reason why the "probe and stud" method couldn't be used in conjunction with a capacitor discharge unit. In effect a board controlling, say 18 points, would be a 36 position push to make switch.
You would get a positive throw every time with no risk of burning out a solenoid and an added bonus is that the studs shouldn't get pitted as they never break current greater than a few milliamps.

 

My method is:

Always use 2 different colours for electric wires for power to the track. (lets says White and Black for now).
On my Layout board where I can turn on / off power to the tracks, I always use "White", which starts at the controller and runs through each of my point activation switches, and on the opposite pin of the switch the white wire runs out to the track on the "outside" rail of the two tracks... i.e. furthest from me, or the one out the outside edge for circular layouts.
Then run the black wire from the controller to the inside track for each section, or the closest rail to me for all places around the layout.

if you have a white wire on the inside, or a black on the outside... then all of a sudden your engine may reverse direction on hitting that section of track !!, you it's easy to spot as youve not followed your standard !

When it comes to Signalling.. use the obvious Red, Yellow, Green Colours, plus one Neutral Colour (say Blue) for the reverse back from the Signal.
And for Points.. again use two unique colours.. say Brown to the layout board, and onto the closest lip of the point, and maybe Orange for the reverse.

Finally, never underestimate the power of labeling your wires... (when you have a few hundred under the board and one comes loose.. it's a nightmare).
My suggestion..

Give each track circuit a number, each signal a number, each point a number.. i.e. Start at one end and continue to the opposite end of the layout (i.e. left =0 right = 100) Also highlight these numberings on your track layout board for identification. It takes 2 seconds to attach a sticky label (at both ends on longer wires), it can take 2 hours to trace an errant wire !!!, but if you find a loose wire with a label, a quick look at your track layout board will show you where it's from and to.

Something like:

Track 1 Circuit 1 = t1c1
Signals on track 1 = t1/s1(r/y/g)
Point Number 1 = t1/p1

This way identifying wires becomes a world easier.

I have in the past also run a single wire back from the track circuit to my layout board and one from the on/off switch to either a blue led.. if it's lit.. the circuit is live... can prevent confusing mishaps!

If your building a large layout for dismantling and transporting... consider using IT infrastructure patching .. i.e. a 24 port CAT5 patchpanel at both ends of the two boards, then plug in the cables in seconds when you reassemble... saves loads of effort and a lot more solid than pin connector cables !

 

Thanks for all the advice guys .

I dont plan on moving it when its done so thats not to bad but the amount of isolatting points ive got on my layout might make wiring it up a bit more interestting .

Im using DC but using electrofrog points so having had to isolate most of the track from each other it helps makes it easier to move / stop engines just makes wiring a nightmere.

 

This sounds intriguing, any chance you post a sketch of the fiddle yard layout and your diode matrix?

 

Do you have any pictures or plans on you're layout Mitch?

 

Talking about points I had trouble with isolated point on my N gauge layout when running tank engines. Some times the loco would get stuck on the points. I’ve cleaned the points up but I still get locos stuck on points when running them at slow speed. Can anyone out there HELP!

 

Lee,

Was it stuck part way between a bend and a point or on the catch of a point? I have had this before because of radiuses on the points and isolation on the points and where the tank engine picks up. how close are the line joined together and where are the pick-up points on the tank engine?