Model Railway Forum

I've just taken delivery of some Hornby R8243 point motors. Following the advice on Brian's website I ordered some 16/0.2 cable ready to wire them up, but I'm surprised just how thin the wires from the point motors actually are. They don't even look 7/0.2 to me, let alone 16/0.2! Am I missing something obvious here? If the guidance is to use 16/0.2 wire, especially if a CDU is being used, which I will be, isn't the weedy cable on the motors an issue?

The cables on some Hornby R406 signals which I've also bought seems to be 7/0.2, which will be man enough for 16VAC at ~1A, but the cables on those point motors suggest that 7/0.2 cable could be used.

Advice and clarification please from people who know far more about this than me!

Cheers.

Remember that a factor in the size of wire needed is the length of the wire needed. A longer run demands a thicker wire so the wires already on the motor are short enough to be less of a factor. Brian’s recommendation covers the demands of a longer run.

Brian, thanks for the prompt reply. That's what I thought. My cable runs, at best will 2-2.5m, depending on they get routed via the underside of the baseboard. If I can get away with 7/0.2 cable I can return ~340's worth of 16/0.2 cable, which will please my wife no end, as I'm bashing the credit card at the moment!

Brian didn’t reply.

If the supplied wires on the motors need to be extended, the you will need the thicker 16/0.2 wires to do the job safely.
Best practice is to terminate the short wires in a chocblock connector screwed under the base board near the point. Then run the thicker wires from the chocblock to the CDU and switches. This arrangement makes changing motors easy in the event of failure and provides strain relief for the wiring.

That was my plan, after studying the excellent information on your website. I suppose that there could be a bit of juice coming from the CDU.

I've got 7/0.2 cable to extend the Hornby R406 signal cables and also for the R618 isolating track sections. The X8011 pins that I need to use for the R046 and R047 switches respectively, will only accept 7/0.2 cable. Soldering is an option I suppose, but I'd rather just crimp those if I can get away with it. My wife wants to have a go at doing some of the the wiring. My soldering isn't brilliant, but hers is non-existent, so anything to keep things as simple as possible is the maxim for today!

Steve is 100% correct.

This is Brian....
Hornby and even Peco pre fitted point motor wires are extreamly thin and really need to pass below baseboard and be terminated into a three way terminal block connector located as near to the motor as practicable.
Use 16/0.2mm wire for all wires from switches or levers to motor and for the return too. If you intend to operate two (or more?) solinoid motors from one lever or switch - a Cross over pair for example, then consider increasing the common return wire used for all motors to 24/0.2mm or even 32/0.2mm.

95% of solinoid motor failures to throw or partial throw are due to a lack of a suitable wire size being used. IMO all wires from power supply to the solinoid motor should be in as a large wire size as practicable and the minimum used should be 16/0.2mm or 0.5mm².

Buffer Stop wrote: ↑Tue Sep 07, 2021 3:32 pm Brian, thanks for the prompt reply. That's what I thought. My cable runs, at best will 2-2.5m, depending on they get routed via the underside of the baseboard. If I can get away with 7/0.2 cable I can return ~340's worth of 16/0.2 cable, which will please my wife no end, as I'm bashing the credit card at the moment!

340 worth of 16/0.2mm ??? Is that pounds £ ?? A 100Mtr roll shouldn't be any more than around £14 to £18. Example.. https://www.bclstore.co.uk/product-page ... us-colours

Steve, Brian, apologies for the name confusion. I don't have the right glasses on at present.

For the points I have a 16VAC feed available from my Gaugemaster Combi controller which will feed a Gaugemaster CDU. This will need to manage 11 points. I have Peco switches in-line with your website Brian (right person this time, I hope!) and am pretty much good to go, using the diagrams that you posted to wire everything up. I'll use 16/0.2 cable throughout, as you suggest, as I have the cable, and reserve the lighter 7/0.2 cable for the stuff that doesn't have much load/demand, such as the isolating track and signals. I have a second 16VAC supply which will be used just for the signals (7 in total) and I don't need anything for the R618 isolating track section, juice-wise.

I wonder why Hornby (and Peco) fit such thin cables to their motors? The length of cable isn't that generous either. It's going to be fun stripping the end of those R8243 point motors. Oh joy ...

1 or 11 point motors makes little difference to the CDU as usually only one or two motors throw at any one time.

I suspect the use of smaller wire size is all down to keeping production and final retail costs as low as possible?

If you have problems with stripping and terminating thinner wires then consider using Ferrules sometimes called Bootlace ferrules
I got an assorted box of ferrules and the crimping tool from eBay suppliers, but I guess Amazon retailers are also available too?
eBay example... eBay link

Thanks for the link. I'll check it out. The CDU will only have to throw one or two points in quick succession, if that. I'm not sure what the recharge times for the caps. on the CDU will be, but I don't think that it matters in my case. My layout is single track branch line with sidings to shuffle stuff around.

I've just got to grab some terminal strips from my local B&Q and I'm good to go. If you hear any wailing in the dark of night, it'll be me ...

I have a Gaugemaster CDU and it's ready to go again in seconds. I only have one pair of points that operate at the same time and they are fine in operation.