Problem with points motor (Surface mounted)

[benread]

My son has a new (non-DCC) track. I have installed a surface mounted points motor and switch but they are not 'switching' the points successfully. The motor works fine when not connected to the points - it throws the switch on command. But when I attach it to the points, it seems to lack the power to change the point. Sometimes it will move it towards the motor, but never away. The power is provided using an older-style controller that is only powering a single point from its accessory power output. The switch and motor are both Hornby products. I have also tried loosening the fixing screws, but the issue doesn;t seem to be the motor jamming, it seems to be that the points are somehow too stiff, even though they move easily when manually changed.

Is there anything else I should be looking at?

Thank you.

[RDS]

Hi benread and welcome to the Forum

I had exactly the same problem (DCC in my case but that makes no difference).  

 

The only way I could overcome it was to use an old Laptop Power Supply that gave an 18v output.  

I have had no problems since.  

 

I will try to find the thread where this was discussed and post a link for you.

[walkingthedog]

A CDU capacitor discharge unit should solve your problem. Well worth using with points even if you have only one motor. Gives the motor a burst of power and prevents motors burning out. Peco make a very neat easy to wire version although it is not ideal if you have lots of points or wish to change two at the same time. Have a Google and see what there is. 

[Rog RJ]

Is this the Hornby R8243 surface mounted motor that you are using or are you using something else?

https://www.hornby.com/uk-en/surface-mounted-point-motor.html

 

Presumably you are using the Hornby R044 switch?

[flyingfox4475]

I had a similar problem with my points. It turned out to be the spring on the points was to strong for the point motor to move. I ended up replacing the point. It then worked ok after that. Before you replace the points try a new point motor first as I have heard that some of the motors sometimes are too weak to move the points against the spring. 

[Chrissaf]

Ben,

Solenoid point motors require a lot of current to fire robustly. The AUX ouput of some controllers just can't hack it. As Walking Dog suggested, a CDU will solve your problem. A CDU works by taking the low current output of a controller AUX output and storing that current in some large capacity capacitors within the CDU. A capacitor has the capability to store enough energy to weld metal contacts together, so when called upon to do so, the energy released by the CDU into the solenoid is high and instant and will fire solenoid point motors robustly.

.

Note however, that Hornby R044 switches are not 100% compatible for use with a CDU due to the way they work internally. This issue is explained on Brian Lambert's web site. Brian also explains how to wire up points with a CDU. A link to his point motor page is given below.

.

http://www.brian-lambert.co.uk/Electrical.html#Motor

.

The Hornby R044 switches are expensive, thus I understand completely that you would not want to replace them with something different just to allow a CDU to be used. However, if it is only one single switch as your post infers then it is definitely beneficial to replace with a different switch to allow a CDU to be incorporated. Note a CDU is a shared resource. Only one CDU is required regardless of the number of points on the layout.

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If you are really adamant that you do not want the hassle and cost of changing the switch or switches and/or the hassle of rewiring to incorporate a CDU. Then your only option is to follow RDS' suggestion of using a more powerful higher voltage power supply instead of your weak controller AUX output.

.

Without boring you (and others) with the physics and maths. A higher voltage power source in the region of 18 to 20 volts is more effective than a lower 12 to 15 volt supply. The laptop type of power supplies are switch mode which means that they can provide high voltage, high current power in a small physical package and very cheaply (relatively) to other types of power supplies. Look on Amazon and eBay for Laptop supplies with an output of 19 volts at about 4 or 5 amps. Expect to pay less than £15 or £20 at most.

[walkingthedog]

The secret of using Hornby switches with a CDU is to operate the switch quickly. I used them for years until I saw the light and replaced them with something neater. 

[96RAF]

With the small black surface mounted motor look at the point tie bar hook as it may be catching on the motor housing. A swift rub with a fine file will drop the tie bar hook clear of the motor housing.

 

Note also that these motors can foul on some diesel underbody parts when they are mounted on the inside of a point curve. Again a swift filing down of the offending corner works well.

[Ralphy51]

I’ve fitted a few of the R8243 surface mounted points and not had any problems . However the latest two have been problematic . The instruction leaflet that comes with the points suggests removing the point spring . I’ve done this and they now work ok .

[Ralphy51]

I’ve fitted a few of the R8243 surface mounted points and not had any problems . However the latest two have been problematic . The instruction leaflet that comes with the points suggests removing the point spring . I’ve done this and they now work ok .