Not sure why motor keeps cutting out.

[ludditte]

I'm hoping someone with better knowledge can help me out please. I have just completed a Boot Lane Works ' Lilibet' (lovely little model) which comes with a 3 -6 v motor and I have fitted a small speaker in the boiler space.I have a 'power & sound wagon' containing a MLS card with a PIko 35040 r/c sender and a 9v PP3 battery linked to the loco via a 4 pin plug & socket to give power and sound. The problem is that when running if it meets any kind of resistance (even a small leaf on the line) the motor cuts out but with the speaker disconnected it runs fine. I have tried different wattage speakers but still the same problem. I don't think the power & sound wagon or its connections are the problem as it works fine when connected to my PDF Models DeWinton - but that does have a 6-15V motor. I'm wondering what the problem may be - perhaps a more powerful motor or any othe ideas most appreciated.

[-steves-]

I would suggest using a different battery to a 9v battery as they are very low discharge rate batteries. If you can get hold of a li-po or li-ion battery you may have more luck running it on a 2 cell pack at 8.4v. These batteries have a much higher discharge rate and may well stop the problem. Certainly worth a test anyway, if you have these type batteries to hand?

[drewzero1]

I agree, in my experience those 9V batteries can't provide a whole lot of current. When the motor has to work harder it draws more current, and my suspicion is that the battery can't provide enough for motor, rx, and sound all together under full load.

Some other battery suggestions: 6x AA alkaline would also get you 9V but (I think) with a lower internal resistance. 7x AA NiMH would give 8.4V with the added benefit of being rechargable. Lithium batteries have a higher power density but also need some protections for safety.

[Phil.P]

You are drawing too much current from the battery..

6 x AA NiMH cells would give you 7.2V but would be marginal for voltage for the MLS card.
8 x AA (or AAA) would gjve you a fighting chance.

Phil.P

[ludditte]

Hi - thanks for your replies. Not sure I fully understand. The batteries I use are PP3 9v 1300mAh rechargeable Li-ion. I get 1.5 hrs running time (with sound) from them when connected to my PDF DeWinton which has a 6-15V motor so can't understand why there would not be enough power if the motor is lower power at 3-6v ?

[drewzero1]

Lower voltage but higher amperage motor maybe? I'll admit I had assumed a PP3 alkaline, which is the extent of my experience with that form factor.

[-steves-]

Lower voltage but higher amperage motor maybe? I'll admit I had assumed a PP3 alkaline, which is the extent of my experience with that form factor.

Exactly that. A 3v-6v motor being powered at 9v is going to draw a lot of current, even at half speed. Those low voltage motors are high current drains for the same wattage. You could always just swap the motor for a 12v 280 size (assuming a 280 size is what's in there at the moment)? That would reduce current drain too.

[ludditte]

Thanks for the suggestions Drewzero & Steves. I've googled 280 size motors and the existing motor size is exacxtly that - its a tight fit so no other size would do. I can only find a higher voltage motor at 12 -24 volts so excuse my ignorance on electrical matters but I assume that would work with a 9v battery ?

[-steves-]

Thanks for the suggestions Drewzero & Steves. I've googled 280 size motors and the existing motor size is exacxtly that - its a tight fit so no other size would do. I can only find a higher voltage motor at 12 -24 volts so excuse my ignorance on electrical matters but I assume that would work with a 9v battery ?

Yes it would work on a 9v battery but it might be a little slow. I use the said 12v-24v motors at 11.1v and they run exceeding well. A 12v-24v motor would certainly pull a lot less in amps than a 3v or 6v.

There are these motors below, but I know nothing about them, I just found them online. They may well be a 3-6v motor and they are just overloading them, I couldn't say for sure either way. If they are truly a 9v motor, then they may be ideal?

https://www.amazon.co.uk/RUBANX-motors- ... C77&sr=8-5

[ludditte]

Thanks Steves - I share your sceptism on that motor as it looks exactly the same as the one that is fitted. I will give the 12-24v motor a go and if not satisfied with it will give it a try.