Bro. Ben

I have made a cable camera powered by a 540 15t hpi brushed motor (pinion 16 spur gear 85). It can take a load of 3.75kg up a gradient of 5 degrees at 5-8kph for 5mins before overheating. I won't to replace the motor and speed controller with something more robust. The load is 3.75kg (ronin m gimble and camera) with gradients of up to 10 degrees uphill speeds of around 15kpm downhill 30kph+. Any sized motor brushed or brushless powered by anything up to lipo 3c up to 11.1v, any brand. Could a 540 4000kv motor like a HPI FLUX VEKTOR do the job or should I go larger? I have know idea because I can't get a kv rating on a old brushed firestorm motor for comparison, But I need to double the power I currently have (15t 540 hpi firestorm brushed 3c 7.4v lipo) Budget for motor and speed controller £240 max.