Need help with peco points and point motors!

[Hogan22]

 

I’ve been troubleshooting my setup for DC point motor operation , and I think I’ve narrowed it down to a few possible options.

I have a bunch of peco point motors wired up, with points attached directly on top, but the motors aren’t throwing the points when switched.

All the wiring is fine, as well as the CDU (16v rkcdu2), and I’m using spdt switches with a centre off. I’ve used a dmm on the exit points of the cdu and it reads the correct amount (15-16v)

And when I use a dmm, with the black lead on the negative of the point motor, and the red on the positive wire entering the operating switch, I still get a solid read of 15-16v but when I actually use the switch (moving the red lead to the relevant throw) the multimeter only reads about 4-6v. Is this normal for standard DC peco point motor operation?

The second thing I believe to be an issue is the tension of the spring in the points themselves, some are more tense than others, and operate differently with the motors. 

Would it be worth looking into adjusting the springs in the points to be less tense, or is this to risky? I know they can be easy to lose. I’ve thought about cutting the springs, but that’s an even bigger risk if it fails to work.

Please let me know what you think I should do, or if there’s anything else I might have missed that could be causing a problem

Thanks for the help!

[smokebox]

How are you powering the cdu?

[cliff park]

The instant the switch contact is made there be at least 15V DC at the point terminals. BUT this will be very brief, quickly dropping to virtually zero as the capacitor discharges. In some respects a DMM is not good for measuring such a transient event.

[Hogan22]

The power supply I’m using for this setup is a 16v ac to dc adapter power supply ( like a power cable from a DC controller).
 

Good to know a dmm wouldn’t really be able to measure the volts going from operating switch to point motor (after switching).
 

that means the issue would likely be the tension of the turnout springs right?

Edited April 24 by Hogan22

[melmerby]

5 minutes ago, Hogan22 said:

Good to know a dmm wouldn’t really be able to measure the volts going from operating switch to poor motor. 

The DMM is perfectly capable or reading the voltage before the switch is operated.

Is is usually quite a bit higher than 15 or 16 volts for reliable operation.

[Hogan22]

Yeah I probably could’ve worded that better, it does get the 16v on centre off, but when I switch its to brief to read it.

 

i thought 16v would be enough, might need to look at some other power supply options then.

 

I do think the turnout springs are playing a big part in this as well, I think I’ll adjust 1 or 2 and see if it makes a difference.

[DCB]

25 minutes ago, Hogan22 said:

The power supply I’m using for this setup is a 16v ac to dc adapter power supply ( like a power cable from a DC controller).
 

Good to know a dmm wouldn’t really be able to measure the volts going from operating switch to point motor (after switching).
 

that means the issue would likely be the tension of the turnout springs right?

I wouldn't weaken the springs, sliding the holder back in its clip on some points can fine tune the tension but too weak and fine flanges will find the gap between blade and stock rail and split the  points.

The Peco motors are a bit marginal throwing  Peco points. at the best of times,  12 volts DC which is effectively, 16 volts AC rectified is not enough,in my experience.   My first thought would be more volts, my Duette delivers around 21 volts  DC off load on a nominal 12 volt output  some other 12 volt controllers deliver  anything between  12 and 24 volts off load and a capacitor will charge towards this off load figure.

Are the SPDT switches all left off.   unless one s being thrown?  because any left on will drain the capacitor.

It might be worth ensuring the blades are free to move?  You shouldn't feel the motor when changing a point manually, if you can its's out of alignment or gummed up.  
I don't like under track direct point mounted point motors as they get crud in.  I prefer the bell crank system or wire in tube from a horizontal motor.  

[Hogan22]

Alright, seems I should leave turnout spring adjustment as a last resort. To clarify, I’m only using the peco standard points, no express points, no electrofrogs, just the plain standard ones.

 

I’ve only considered adjusting the springs as some of my peco points are easier to switch then others, none of them are particularly older or more worn out then others either.

also, I believe I am using 16v DC not AC, that stuff does sort of confuse me a bit, but the output of the power supply adapter reads 16v DC.

 

 

yes I always make sure to switch all the spdt switches to their centre off before switching again, if I tried to do that without switching all to centre off it just wouldn’t work period.

 

the blades are 100% free to move, not obscured by anything, even with the motor underneath they still switch fine manually.

 

id prefer not to have these mounted directly under the track myself, but the track is on a 6cm thick table (4cm foam board, 2cm wood), I was originally going to mount motors under the table, but the distance the motor rods needs to travel, plus the resistance from the points, it’s just not really an option unless I invest in some heavy duty equipment.

 

 

[kevinlms]

1 hour ago, Hogan22 said:

also, I believe I am using 16v DC not AC, that stuff does sort of confuse me a bit, but the output of the power supply adapter reads 16v DC.

 

So yes, you are only supplying DC to the CDU. If it was 16 Volts AC, the voltage at the output of the CDU would be more like 22 Volts DC.

 

Having said that, the point motors should be at least attempting to throw. Have you a spare point motor that you can temporarily connect to the CDU output and see if that works?

[Hogan22]

That’s the thing, when the motor is in or out of the board without being connect to points, it throws no problem, if I then attach a set of Hornby standard points to the motor (in or out of the table), it usually throws them as well, But if I try that with my peco points, in or out of the table, they won’t throw. I really do think it’s an issue with the tension of the spring in the points, but I’ve been recommended against adjusting the springs so I’m a bit lost as to what to do about all this.

[kevinlms]

4 minutes ago, Hogan22 said:

That’s the thing, when the motor is in or out of the board without being connect to points, it throws no problem, if I then attach a set of Hornby standard points to the motor (in or out of the table), it usually throws them as well, But if I try that with my peco points, in or out of the table, they won’t throw. I really do think it’s an issue with the tension of the spring in the points, but I’ve been recommended against adjusting the springs so I’m a bit lost as to what to do about all this.

Increase the voltage to the CDU, using AC. I've never had to remove springs, but I guess you could try that on one, if it would make you happier.

Remember the springs help to keep the blades over, not just to prevent the blades from moving!

[Hogan22]

Oh no the idea wouldn’t be to remove them entirely, just to take them out, adjust them slightly and put them back. Hopefully the result would be slightly less resistance when switching them.

[Brian]

Are you able to power the CDU from another source? A 19 to 21 volt DC laptop power brick would be ideal as a test supply.  Or use 16v AC (uncontrolled AC outlet on a train controller)

Also is all the wiring CDU output to the switches, switch to its motor and the return in a suitably large wire size? I recommend the minimum to be 16/0.2mm equipment wire. 

Do not connect two solenoid motors together (in parallel) linking from first motor to second as the first will "Grab" all the power. Best is to run wires from the switch position to each motor and try to keep the wires all to roughly the same length, use a terminal block near the switch if need be to allow extra connection room for these added wires.

[Hogan22]

55 minutes ago, Brian said:

Are you able to power the CDU from another source? A 19 to 21 volt DC laptop power brick would be ideal as a test supply.  Or use 16v AC (uncontrolled AC outlet on a train controller)

Also is all the wiring CDU output to the switches, switch to its motor and the return in a suitably large wire size? I recommend the minimum to be 16/0.2mm equipment wire. 

Do not connect two solenoid motors together (in parallel) linking from first motor to second as the first will "Grab" all the power. Best is to run wires from the switch position to each motor and try to keep the wires all to roughly the same length, use a terminal block near the switch if need be to allow extra connection room for these added wires.

Potentially, I believe the cdu I have is only designed for 16v, so should probably get a new one that can handle more.

 

is upping the power by a few volts really gonna make a difference? The motors throw fine when not attached to anything, and also throw with Hornby points, it’s only peco ones they seem to have trouble with. 

[Free At Last]

1 hour ago, Brian said:

Do not connect two solenoid motors together (in parallel) linking from first motor to second as the first will "Grab" all the power. 

Not always.

I have never wired two (even three) motors in any other way and they have never failed to switch.
 

[Brian]

You're very lucky!  Electricity is basically a lazy item and will always flow to the path of least resistance (usually in this case the first solenoid motor coil) hence the second coil when linked coil to coil only gets a tiny amount of power, if any at all.   I only offer the best advice to help stop later issues which with a solenoid is to run separate feed wires from the switch.

 

2 hours ago, Hogan22 said:

Potentially, I believe the cdu I have is only designed for 16v, so should probably get a new one that can handle more.

 

is upping the power by a few volts really gonna make a difference? The motors throw fine when not attached to anything, and also throw with Hornby points, it’s only peco ones they seem to have trouble with. 

You haven't said what Peco solenoid motors are being used? PL-10 or surface PL-11? If PL-11 these need fitting so as they are not to pulled down too much.

You haven't said what wire size is being used for feeding to motor and the return?  Just "All the wiring is fine" which is a bit unclear.

Also to be 100% clear are the operating switches non locking sprung to center Off type (On)-Off-(On) rather than locking switches? Also worth noting is the need to wait a second or so for the CDU to fully recharge before the next switch operation takes place.

 

16v maximum is quite a low input voltage for a CDU.  Take a look at the capacitor(s) and they should have both their microfarad rating and their DC working voltage shown on their case. This will set the maximum volts the capacitor can handle safely. Over this you risk them exploding!    Is this the CDU you're using and mentioned at the beginning  Link to CDU  If the image is correct, the four capacitors are rated at 35 volts DC so well withing the proposed 19 to 22 volts DC.

If you have a 19 to 22 volt Power Supply (As I suggested a former laptop brick style Power supply is ideal). You can always try this without the CDU in circuit and the current output of the power supply at usually around 3 to 4 Amps should move a solenoid motor easily. 😀 

 

Of interest, a CDU has to convert an AC input to DC to store the charge in the capacitor(s). If the input is an AC supply, then the capacitors will charge to the Peak AC value of the supply. This is 1.4 times the RMS voltage (RMS is the one usually quoted for an AC supply) so if the supply provided 16v AC (RMS) the capacitors would charge to around 22 volts DC minus a little bit for the rectification diodes in circuit.  Hence a higher DC input voltage can normally be used i.e. 19 to 22 v DC.    

Edited April 25 by Brian

[Philou]

@Hogan22 Just as a thought - is your track ballasted? It only needs a bit of ballast or a drop of PVA to either stop the blades from throwing or gumming up the tie-rods. Been there, done that!

 

Cheers,

 

Philip

[melmerby]

The TKcdu2 has 4x 35v 4700μF capacitors which I would've thought, should be enough to throw any solenoid.

However 16vAC will give about 40% more DC volts at the caps.

 

[Free At Last]

22 minutes ago, melmerby said:

The TKcdu2 has 4x 35v 4700μF capacitors which I would've thought, should be enough to throw any solenoid.

However 16vAC will give about 40% more DC volts at the caps.

 

I use one, it works ok, it throws pairs of motors linked together, but is noticeably slow recharging compared to my Gaugemaster one which recharges quicker than I can operate the switch. Both supplied from the same transformer.

Edited April 25 by Free At Last

[kevinlms]

13 hours ago, Hogan22 said:

Potentially, I believe the cdu I have is only designed for 16v, so should probably get a new one that can handle more.

 

is upping the power by a few volts really gonna make a difference? The motors throw fine when not attached to anything, and also throw with Hornby points, it’s only peco ones they seem to have trouble with. 

You can check whether it's suitable for higher AC Voltages. Look at the capacitor(s) - the largish round things. If it says that they are 35 Volts or more, then YES it is suitable. If not sure tell us the voltage it says.

 

Yes, increasing by a few volts will make a difference, because the result at a CDU is the peak of the AC input, not just the RMS (think of average value - although technically incorrect), which is the voltage a multimeter will measure.

 

I realise it's hard, because it appears that you're getting something for nothing, but if you try it out, you'll find that it's true. This is because the output from a CDU is a momentary one and NOT a constant output, which would show it's true colours!

[Suzie]

On 24/04/2024 at 23:31, Hogan22 said:

The power supply I’m using for this setup is a 16v ac to dc adapter power supply ( like a power cable from a DC controller)...

 

I think that this is the problem item. I don't know what it is, but you need to replace it with something that gives out at least 24V DC or at least 16V AC. 16V DC is not enough input to a CDU.

[ColinK]

A long shot, but try swapping the output wires from the CDU - remember CDU output is DC.

[Hogan22]

Thankyou everyone for the help! 
 

in case it wasn’t extremely obvious, this is my first time doing anything like this, so please forgive me if I misunderstand any advise you’ve tried to put forward.

 

there’s been a lot of trial and error on my end, and I’ve been close to giving up on all this. 
 

I probably should be a little more specific about how I’m going about all this, so I’ll list some things below: 

 

I’m using the power supply from a Powerline PR-TC2 DC Train Controller (ac -16vdc power supply adapter)

 

im using 13x0.12mm wire to connect the cdu to the switches, terminal blocks and motors.

 

im using a TKcdu2 CDU, which apparently has 4x 35v 4700μF capacitors (good to know 👍).

 

im not sure as to the specifics of the switches I’m using (non locking sprung vs locking switches) the switch doesn’t spring back to centre off after switching if that’s what you mean 🤷‍♂️

 

the switches I’m using are these:

https://www.jaycar.com.au/spdt-centre-off-miniature-toggle-switch-solder-tag/p/ST0336?gad_source=1&gclid=EAIaIQobChMIrc62gKzahQMVPmoPAh062Q4BEAQYAiABEgIylPD_BwE

 

id be happy to change the switches if it would help, are the peco pl-26r switches good for this sort of thing, or not much better than what I’m already using?
 

the peco point motors I’m using are the pl-10 motors.

 

And the track I’m using is not ballasted.

 

i think I’ll try and get a 24v dc output power supply tomorrow, and see if that works. If not, I’ll try an old laptop charging cable instead.

 

 

 

 

 

 

 

 

Edited April 26 by Hogan22

[ejstubbs]

On 25/04/2024 at 10:08, Brian said:

Do not connect two solenoid motors together (in parallel) linking from first motor to second

 

Far be it from me to quibble with the author of The Newcomer's Guide to Model Railways and owner of this immeasurably useful web site, but if you mean wired from the CDU (via the switch) to the first solenoid, then from the first solenoid to the second, then back to the CDU, then surely that's in series, not parallel?  Or is my aged brain becoming even more addled than I realised?

 

On 25/04/2024 at 10:08, Brian said:

Best is to run wires from the switch position to each motor

 

That's what I would call parallel wiring.

 

34 minutes ago, Hogan22 said:

im not sure as to the specifics of the switches I’m using (non locking sprung vs locking switches) the switch doesn’t spring back to centre off after switching if that’s what you mean 🤷‍♂️

 

the switches I’m using are these:

https://www.jaycar.com.au/spdt-centre-off-miniature-toggle-switch-solder-tag/p/ST0336?gad_source=1&gclid=EAIaIQobChMIrc62gKzahQMVPmoPAh062Q4BEAQYAiABEgIylPD_BwE

 

Those are normal SPDT switches.  If using them for point motors you'll have to remember to re-centre the toggle after every point activation.  As DCB said above, leaving just one point switch in either of the non-centre positions will prevent the CDU from charging.  For solenoid point motors I would have thought that it's always better to use what are called momentary toggle switches, which return to the centre position automatically when you take your finger off the toggle.  These are also sometimes described as (ON)-OFF-(ON) switches, where the brackets indicate that the toggle does not 'latch' in those positions.  

Edited April 26 by ejstubbs

[St Enodoc]

52 minutes ago, Hogan22 said:

Powerline PR-TC2 DC Train Controller

You need to get an AC supply as mentioned several times above.

 

Jaycar MP3021 will give you 16Vac but I'd suggest MP3032 which will give you 24Vac.

 

59 minutes ago, Hogan22 said:

the switches I’m using are these:

https://www.jaycar.com.au/spdt-centre-off-miniature-toggle-switch-solder-tag/p/ST0336?gad_source=1&gclid=EAIaIQobChMIrc62gKzahQMVPmoPAh062Q4BEAQYAiABEgIylPD_BwE

Jaycar don't seem to offer an (ON)-OFF-(ON) switch, which is surprising. Peco passing contact switches PL-26R are also suitable.

 

Good luck!