TboltBeardie

I have read and heard countless times that brushed motors are waterproof and should be broken in underwater. Brushed motors have an open mechanical switch, so how on earth are they waterproof? It defies everything I know about electrical apparati.

Rodney

Yes they are water proof. Back before brushless motors were readily available, most RC electrics had no other choice. It was always recommended to run the motor under water to break in the brushes to get maximum efficiency. This was quite common and practiced by most users. Just hook up your battery to the motor and immerse it in a tank of water and run the battery down.

MajorTomski

I did that once and there was a LOT of carbon on the bottom of the container. I'd check it every 5 min or so just to look in and see if the brush has seated, not worn itself half way down.

TboltBeardie, the little can motors we use at the low voltages we use run just fine in fresh water. They don't 'short out' as one would believe.

topspin

I used brushed motors for years and they worked really well but I was always skeptical about the breaking them in under water thing. I have done it but it's best to use distilled water because some water has a lot of mineral content that besides being conductive can mess up the bearings. GWS motors had "oiliness metal" whatever that is so they didn't need lubrication but for all of my motors and gearboxes that I ran under water or in the rain I sprayed them with WD-40 and then applied some 3 in 1 oil to the bearings and they just kept running.

The reality is that brushed motors are not that bad. They have low torque but very high KV and so are good candidates for gear boxes and larger props. Back around 2000 using a geared GWS 400 brushed motor and 1147 prop on a slow stick with a 2100 mah Lipo battery I was able to lift 1.8 pounds of excess equipment.