hornby surface mounted point motor

[daleks04]

thanks,

i am currently using the following items:

GAUGEMASTER 16V CDU
7/0.2mm BOUGHT FROM NRM SHOP 0.2mm Equipment Wire (100m) THE LINK:

http://www.newmodellersshop.co.uk/elect ... 20wire.htm
SRUNG TO CENTRE TOGGLE SWITCHES SPDT
STRIPBOARD

im not sure on the stripboard, what else could be used, and also, will my wire need changing?

thanks

amarjot

[Flashbang]

Hi
Sorry but 7/0.2mm is not large enough for solenoid motor operation or return!
Use as an absolute minimum 16/0.2mm and better 24/0.2mm or even 32/0.2mm for all feeds and return wiring.

[daleks04]

but then what about the hornby point motors?

the surface mounted ones have thin wires already attached?

amarjot

[Flashbang]

but then what about the hornby point motors?

the surface mounted ones have thin wires already attached?

amarjot

Hi
Thin??? If Hornby have pre wired their point motors correctly, it would be 16/0.2mm or similar!

[daleks04]

I don't understand? I have a hornby surface mounted point motor with thin wires and I bought the railway modelling wire a long time ago, to use for point motors as it says. The wire actually is thicker than the ones supplied attached to the point motor. Maybe the wire size on nrn was incorrect( see link)

[Flashbang]

Hi
I can't look at a Hornby motor to determine what wire they factory fit, as I dont use their products!

7/0.2mm wire will work a point motor, (as too would a length of bell wire!) but it will often lead to poor motor performance! Its just not up to the job in its conductor sizing. Often the problems manifest themselves when using a too smaller size of wire as - point fails to throw every time or partially throws etc resulting in a second or at times a third try on the point switch.

Its a pity retailers sell 7/0.2mm such wire under the generic label of "For Model Railway use" and especially if "For solenoid point operation". Its either they have no electrical background or simply dont understand what occurs when a pulse of current (around 3 to 4 Amps) tries to flow in an undersized conductor. Volt drop occurs resulting in serious loss of volts at the far end. 7/0.2mm is fine for many model railway uses, but not solenoid point motors.

If for solenoid motor feeds you always use 16/0.2mm wire as a absolute minimum size, then you shouldn't ever have problems over shortish distances and on longer wire runs use larger sizes of wire - 24/0.2mm or 32/0.2mm.
Example... 16/0.2mm wire is what Peco supply for their points and sell it as 'Point wiring packs' !

You will get some people who'll pop up and say "But all my points work on lengths of damp string / bits of fuse wire etc etc and have done so for the last ten years!" But in reality and probably unknown to them they actually do suffer volt drop issues and point operating performance suffers or they have added a CDU to try and over come the problems.

My best advice I can offer is.....If you always aim to have the largest size of wire conductor practicable then you shouldn't ever have operating issues caused by volt drop.

But in the end its entirely up to you. If you choose 7/0.2mm for your solenoid point motor operation wires that's your decision.

[hobby boy]

I thought that i should point out that the attached wires on the hornby surface mounted point motors aren't as thick as 7/0.2 wire. it is much much thinner. On the normal point motors, they are 7/0.2 to 16/0.2

Andrew

[Flashbang]

I thought that i should point out that the attached wires on the hornby surface mounted point motors aren't as thick as 7/0.2 wire. it is much much thinner. On the normal point motors, they are 7/0.2 to 16/0.2

Andrew

Hi Andrew
If you have one, how many strands of wire are inside the insulation?
Peco provide 16/0.2mm wires.
In the mean time, I'll contacting Hornby to see what they state is used on their motors.

[daleks04]

i have one,from what i can see, there is the plastic casing around a single wire

amarjot

[Flashbang]

i have one,from what i can see, there is the plastic casing around a single wire

amarjot

Hi
I'd be surprised if its a solid single core wire? As it would snap eventually if flexed too much!
Its possibly the soldered ends looking like a solid wire you can see?

[hobby boy]

i think it is about 1/0.2 wire in the point motors as it kept slipping out of my terminal block. The 7/0.2 wire stays in fine.

Andrew

[daleks04]

so what should i do?

[Flashbang]

Hi
I have received from Hornby, as samples, two point motors. R8014 standard motor and R8243 Surface motor.

Test One...
Assuming these are as normally supplied (they both work ok) the factory fitted wires are as follows....
All wires are factory soldered at their stripped ends, making them appear as a solid conductor, but by cutting off the soldered ends and carefully stripping back the coloured insualtion the inner stranded wires were revealed.
R8014 Standard motor has 11/0.1mm2 wires attached.
R8243 Surface motor has 7/0.1mm2 wires attached.

Test Two...
Next test was to determine the motors coil resistance as this will be used to calculate the current flowing in circuit.
R8014 measured Black wire to Green 5.40 OHMS and Black wire to Red 5.43 OHMS.
R8243 measured Black wire to Green 2.80 OHMS and Black wire to Red 1.42 OHMS. I was rather surprised to see such a difference in the two coils resistance of this motor!

Now by using OHMs law where current (I) equals the supplied volts (V) dived by resistance (R)
R8014 operating at 16 volts dc will consume approx 2.95Amps. (one coil being 16/5.40 = 2.962 and the other coil 16/5.43 = 2.946)
R8243 operating at 16 volts dc will consume approx 5.71Amps one way and 11.26Amps the other.

While I appreciate if 16 volts ac is used the current flowing will be slightly different due to the ac peak voltage being different to that of dc. But using dc is easier to calculate!

However, what is of concern is the size of the wires on the R8243 surface motor. They are IMO far too small in wire gauge. This may be why many people are experiencing operation problems with this motor. The wire is just not up to the load being placed upon it even if that loading is momentary!

My advice would be where the R8243 surface motor is being fitted then do not extend the length of the factory fitted wires beyond that supplied (my sample had wires some 150mm long fitted). From the ends of the factory fitted wires run in as a minimum 16/0.2mm2 wires for feed and return and where the wire run exceeds some 6 mtrs (20 feet) then increase those wires to 24/0.2mm2 or even 32/0.2mm2. This would ensure adequate wire sizing and should prevent poor motor performance.

In the meantime I shall be back in contact with Hornby to discuss this whole issue. Seeking their comment.

You can view the OHM readings obtained here...
http://s190.photobucket.com/albums/z311 ... %20Motors/

[Bufferstop]

Well done Flashbang for starting a dialogue with Hornby. Their point motors seem to suffer from being made in the land of the MP3 player where minimal conductor sizes abound. Whilst waiting for some sort of response from Hornby it's worth pointing out to anyone struggling with these motors that if the thin wires can't be replaced they can at least be shortened. Just long enough to go through the board or hide under a bush then joined (soldered for preference, otherwise a good clamping connector) to the recommended sizes. When it comes to removing unwanted resistance, as they say "every little helps"

[daleks04]

thanks so much,

i will use the point motors, with 15v dc 1a, with peco 16/0.2mm wire!