Motor advice

[Deckie]

I have several tiny electric motors like this https://www.ebay.co.uk/itm/225061248900 but to spin a scale propeller it ideally needs to be of the type that is off until you give it a little push so there’s no need to mount an on/off switch anywhere. I’ve tried Googling them but nothing comes up, probably because I don’t know what they’re called and describing them didn’t help either. The last time I saw one was in a 1/32 scale Airfix kit of a Spitfire I made 50 years ago in 1972. Can anyone advise please on whether these motors still exist (or if there’s a better solution that doesn’t need an on/off switch).

Thanks.

Edited November 25, 2022 by Deckie

[malpaso]

Dinky and Frog used similar flick-start motors as Airfix.  This webpage explains how they worked:

 

Frog motor explanation

Airfix explanation, see half way down

 

Airfix, Dinky and Frog used the same motor.  You’re looking for a Mabuchi RM-01; whether Mabuchi or anyone still makes that type of motor is a good question; cannibalising old Dinky aircraft probably wouldn’t be economic!

[Pete in Lincs]

I have a boxed Mabuchi motor in the mancave. I just checked but it's a 130. It works as soon as a battery is connected.

However, I'm sure that I read decades ago that the trick is to cut one of the winding wires. 

This shorts out the circuit until you spin it and the speed means that the cut doesn't matter.

It might be worth a go on a spare motor?

[Deckie]

Thanks Malpaso, I gather that these motors no longer exist which is a shame. I searched for "Mabuchi RM-01" and "flick start motor" but no results. I’ll have to think of another solution, probably having to use an on/off switch unless I leave the propellers static.

 

Thanks Pete, I’ll have a close look at one of the motors and see if I can cut one of the windings. The propellers are quite small and light so there may not be enough inertia to keep the motor running.

[Rob G]

Add a normally closed magnetic reed switch into the circuit. To turn it off, place a magnet next to the switch's location, remove it to turn it on. If you're putting it into a diorama, the magnet can be concealed inside a crate or barrel (or even a figure, if the scale's large enough) so that it's not an eyesore when things are static. 

[Deckie]

Thanks, that’s a great idea Rob G. I do have some miniature reed switches and some tiny neodymium magnets for a similar purpose. I think they’re normally open but it could work, the model is a Lancaster so there may be room in the bomb bay or somewhere. I’ll have to fashion somewhere to put the batteries.