Hi Geo,
If we're talking prop shaft speed, then my Yanmar SVE12 had an operating range of about 400 to 1600 rpm. My electric drive is configured for 80 to 750 rpm.
If I slow the motor below 200 rpm, it seems to run less smooth. I think that the permanent magnets of the Mars motor start "stepping" at very slow speeds. Has anyone else noticed anything similar with the Mars PMAC motor? I'm running a Gen4 controller.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, GNHBus@... wrote:
>
> friends call me Geo,
>
> I consider shaft rpm an identifier for propeller thrust.
>
>
> In a message dated 3/10/2011 2:34:37 P.M. Eastern Standard Time,
> ewdysar@... writes:
>
> GNHBus,
>
> Just curious, when you think RPM, are you thinking of motor speed or prop
> shaft speed? (I'm guessing motor speed). I'm only bringing that up because
> we've all got different reduction ratios, so any reference to RPM in motor
> terms will need to be qualified with reduction ratio for any meaningful
> comparisons.
>
> It's similar to why we use watts and watt hours for loads and capacities,
> amps and amp hours don't mean much without stating the voltage.
>
> Eric
>
> --- In _electricboats@yahoogroups.com_ (mailto:elec
> tricboats@yahoogroups.com) , GNHBus@ wrote:
> >
> > Based on this great info below,validated by the "pull tests" it becomes
> > easy to see how converting to electric propulsion for sailboats @ 3-4
> knots
> > allows for applying the Instant Torque
> > Power Curve to a very efficient propeller at relatively low rpms
> > (@1000-1800)
> >
>
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