lowest voltage that will move an OO loco

[kebang]

Currently trying to find the best, cheapest, way of providing power to the layout.
At the moment I am using a cheap Chinese pwm power controller connected to a 12v battery. Considering the outlay the results are very acceptable. However I have noticed there is only a very very small rotation of the control knob for voltages between 0 - 5volts, making it very difficult to accurately select a low voltage in this range. So I am running reasonably slowly at 5v, but anything below this is very hit and miss.
If, by luck I hit on 3.25v I achieve shunting speed! (Otherwise I stop, reverse and try again )
So I've ordered this from China, for 3.00 GBP ,inc postage

I have no idea if this will be an improvement or not.
I will also try the original controller on a 6v battery, but this will reduce all traffic to slow!
I realise after all this I might still end up having to buy a 'proper' controller. the most economical one I can find at the moment is this:
Gaugemaster COMBI-AU Combi 12v 1Amp Australian Single Track Controller (28.00GBP+ postage, so around 40GBP )
Anyone have any experience of this? Anyone got any other suggestions?
Thanks, Kebang

[kebang]

OOPS!
I meant to post this under electrical. Could an op please move this for me, thanks

Sorted. Dave-00

[Lofty]

I suspect that it will be as advertised… Cheap and nasty. Hopefully it’s not.

A decent controller with a bit of umph is a good investment IMHO, it may look a bit pricey on day one, but you are only going to buy it once, it should last years and will perform far better than a poor one.

[kebang]

you are probably right Dave! However a new gauge master with transformer and postage is going to cost me around 70.00GBP. each one of theses little experiments costs me less than a pint! (inc. postage) If I can find something that works really well thats great. If not I'll carry on testing until my daughter brings me my new locos and track at the end of this month.
So if any electronics people are reading this please chip in!

[kebang]

Getting back to the Topic ( lowest voltage that will move an OO loco), at the moment I only have access to 2 of my locos, both 0-4-0 Hornby locos. One is only a month old, starts and stops moving at around 3.2v. The other is a lot older, but still not one of the original 'Rockets!' This cuts in and out at 7.8v, so its almost a stop and start switch.
I'm hoping that these are not normal!
My new Bachman L&YR 2-4-2 arrives in 2 weeks time, I'm hoping that this shows a better cut in/out voltage, or at least a slower start speed....
So does anyone know the cut in and cut out voltages of their locos? (DCC does not count! )

[kebang]

OK Dave, I bit the bullet! A new Gauge master controller (23.33 GBP) is now in my Hattons Trunk and a new 16vac 1amp transformer(722php,or 11quid, inc. postage) is enroute from China. The experiments will continue though, and hopefully I will be able to offer measured comparisons in the future for the benefit of other cheapskates like myself!

[Bigmet]

I have used a Gaugemaster Combi briefly while unexpectedly sorting out a problem on a child's layout, and it worked well for the asking price. I would have liked to try it with a 'known' loco of my own to really assess its capability, but many hours drive from home precluded this...

...My new Bachman L&YR 2-4-2 arrives in 2 weeks time, I'm hoping that this shows a better cut in/out voltage, or at least a slower start speed...

My 20-odd years accumulated experience of several similar Bachmann mechanisms is that their compact very efficient 3 pole motor with a small diameter worm on a free running spur gear train gets away on a breath of current. It is a good plan to run the mechanism for at least an hour at a moderate speed, running for equal time in both directions, and turning the loco around on the track circuit halfway through, to fully 'exercise' the mechanism for direction and curvature. This polishes the wheel to rail and wheelback to wiper contact areas, and distributes any lubricant 'blobbed on', which typically helps get the best out of the mechanism, especially in starting and low speed capability.

... So does anyone know the cut in and cut out voltages of their locos? (DCC does not count!)

Not anymore! Now that competent RTR mechanisms are standard, and there is a readily available control system that offers programmable customised control over such mechanisms, the one time need to measure starting voltage has 'gone away'. (I'll leave out any discussion about whether this is continuous current or modulated.)

(The trouble from your perspective is that DCC (and related methods) inevitably do 'count' as far as RTR productions are concerned. Those designing the mechanisms face pressure to minimise component cost and simplify assembly, and will factor in electronic control methods as 'standard' for producing acceptable on track performance.)

[End2end]

The lowest voltage that can move a loco is 0v ............ and a finger.
Bleedin' dirty track!
Thanks
End2end

[Phred]

End2end wrote:
The lowest voltage that can move a loco is 0v ............ and a finger.
Bleedin' dirty track!

Too true! A well placed finger has supplied motivation for many a reluctant loco at my place.

[kebang]

Thanks for all the replies!
I cannot expect to have received all the goods on order until mid April. I'll then run extensive tests to evaluate what works well and what doesn't.... (I've never made a utube vid, wonder if its worth doing once I have the results of the experiments..)
Thanks for the Bachmann 3 pole info Bigmet, I'm like a 70yr old kid waiting for Xmas!!

[kebang]

Just found this page:
https://www.scottpages.net/ReviewOfControllers.html
Makes my planned experiments look rather futile!

[Bigmet]

Good overview. Explains very well why I use a resistance controller (the very neat and shiny looking H&M Duette illustrated) for testing mechanisms ahead of decoder installation. These devices offer no help whatsoever to the motor, and more so at low speed, and thus reveal any mechanism problems such as cyclic binding for rectification. (Mine has the once optional high resistance mats which helps with modern motors which start on very low current, but typical DC resistance controllers only need a large external resistor in the track supply to function equivalently.) Once a mechanism consistently runs smoothly at dead slow (scale for walking pace or less) operated by such a DC controller, it can be considered 'sorted'.

[Bufferstop]

One correction to the linked article. The reference to autotransformers is incorrect. All of the control units shown use conventional transformers followed by a rectifier. An autotransformer has one single multitapped winding and would never be approved for use in toys and models as there is a direct wired connection between the incoming supply and the wiring of the secondary. In a conventional transformer the primary and secondary windings are only connected via a magnetic field. H&Ms Powermaster and also one of their Safety Minor units used a transformer with a variable tapped secondary, one face of the secondary winding was exposed and a carbon brush on an arm traversed it's surface in an arc, (clearly visible in the opened up view) giving a tap to a changing number of turns and thus a varying voltage without using a resistance mat. For the higher consumption motors common at the time it gave better control without having to insert or switch out resistors to make it match the motor. The improvement in motor power brought about by the adoption of rare earth metals allowe even the cheapest motors to have a higher resistance winding and lower current consumption, making additional resistors unnecessary.

[kebang]

I've noticed that, with a PWM controller I can set the track voltage to, for example, 5.1v and it remains steady (according to my tester). When I place the loco on the track the loco runs and the voltage reading increases and is constantly changing (between 7.1 to 7.7). When I remove the loco the voltage returns to 5.1v.
Does this mean that the PWM controller is 'flickering' between the 0 to the 12v that is available from the battery, and this is what can cause the overheating of a loco? (This one doesn't seem to be getting hot). If this is the case I think when it comes to running in a new loco I'll connect the track, through a DPDT switch, directly to a 9v battery. (or possible a 6v battery if that seems too fast for running in)
Is this a wise precaution?

[Dad-1]

You certainly have some interesting problems Kebang,
Next you'll have a bicycle with dynamo set up so you can power your
tracks, keeping fit at the same time ?

Sorry but I've already given my training rollers away.

Geoff T.