Saturday, July 11, 2009

Re: [Electric Boats] Direct drive brushless DC motors now available



To be fair, both of Arby's prior references were future tense - so yeah he was late, but that hardly constitutes deception. He's contributed meaningfully to the group, has an apparent wealth of knowledge and has a product that will likely prove useful to at least some members of the list.

That TS hasn't updated their site is also not surprising. They are probably busy with yet-another motorcycle that can tear it's own tires off.

But...healthy skepticism is warranted, and I would be extremely interested in some actual speed/watt and efficiency graphs. One marketing challenge is that the alleged increase in efficiency will only be obvious in actual installations - it's unlikely the motor itself will show more than a few percentage either way. It's the removal of drivetrain loss factors (belts, chains, bearings) that should make the most difference.

-Keith

--- In electricboats@yahoogroups.com, "Myles Twete" <matwete@...> wrote:
>
> Arby, respectfully, you have been claiming literally for months now that
> your new drive assembly was "available at Thunderstruck-EV". Again you
> claim this, and again, while there are a half dozen different makes of
> motors listed on that site, there's not a single web page I can find at
> Thuderstruck substantiating they stock your motor/controller. There are no
> text references, let alone photos, motor specs or motor curves for your
> motor/controller. Now maybe they are available or maybe not---but to have
> folks "call Mark" sounds more like you're asking us to build demand for
> Thunderstruck to buy these from you, stock them and post them as
> available---which they seem reluctant to do. As we still haven't seen
> publicly available performance specs for your motor/controller, I'm
> skeptical---and perhaps Thunderstruck is also. Please don't post to this
> list that your hardware is available from a substantially website-based
> company that hasn't even mentioned your hardware on their website.
>
>
>
> Moderator NOTE to ALL: This is not a sounding board or focus group for
> marketers, developers, thesis writers, etc. Attempts to use this list in
> this manner leads to your list postings being moderated (including being
> delayed, edited or deleted).
>
>
>
> -Myles Twete, List Moderator, Portland, Or.
>
> From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com]
> On Behalf Of arbybernt
> Sent: Friday, July 10, 2009 12:34 AM
> To: electricboats@yahoogroups.com
> Subject: [Electric Boats] Direct drive brushless DC motors now available
>
>
>
>
>
>
>
>
> Now available at Thunderstruck-EV: The Advanced Marine Electric Propulsion
> 24v, 2kW, direct drive brushless DC motor specifically designed to replace
> inboard ICEs in sailboats up to 32 feet. With an internal controller, the
> motor unit is sealed to 10' of temporary submersion, yet vented to dry air
> to maintain atmospheric pressure within the motor housing, relieving seal
> pressure and eliminating grease migration. The 1" keyed stainless steel
> shaft extends eight inches from the motor rear face to accommodate hull
> curvature. The shaft exits five inches up from the bottom of the motor
> housing, and in the center of the 9.375" width. The motor housing is 13.75"
> tall, 3.25" thick, and weighs 30 lbs. Mounting is achieved via four 1/2 x
> 13tpi tapped heli-coiled blind holes, arranged symmetrically about the drive
> shaft on the sides of the housing. Simple mountings can be fabricated from
> 2"x2" aluminum angle, or with 1/4" aluminum plates secured to both the motor
> and engine stringers. Wiring does not require a relay or any external
> battery switch. Battery leads are designed to be connected directly to the
> main battery. A second string can be combined with the primary string using
> a two position switch. Logic power is controlled by a remote switch, and
> consumes a mere 40mA on standby (50mA with an LED power indicator). When the
> logic power is off, there is no measurable battery drain. There are no
> exposed terminals, no additional connectors, and no external wires between
> the motor and the controller. With a no-load speed of 1000rpm, the motor
> achieves peak output at 875rpm, making the use of large efficient propellers
> possible. Although an aggressive prop will provide peak performance, the
> motor torque range is broad and efficient, making nearly any prop functional
> without modifying the boat. I'm currently fitting a Ericson 27 (6800lb
> displacement) with an Advanced Marine motor and an 11x11 3bl prop, having
> met success with both a 30' Hunter (9700lbs, 12x7 2bl prop) in St.
> Augustine, Fl, and a 30' custom sailboat (~8000lb, 12x8? 2bl prop) in
> Marshall, Ca. Both boats have been providing reliable service, and cruise
> comfortably on 24v at 40 to 60 amps. I hope to splash the Ericson this
> weekend, and will be conducting testing next week, pending an unpredictable
> travel schedule, in the challenging conditions of San Francisco Bay. I'll
> post pictures and stats when the installation is complete. Energy will be
> provided by two sets of 2x12v, North Star NSB100FT 100aH AGMs, located
> within the existing motor compartment. Cooling is provided by a shaft
> mounted fan, directing air across the rear of the motor housing. Motor
> control is achieved with two encapsulated switches (logic power and prop
> direction) and a mil-spec wash-down grade potentiometer for throttle level,
> all provided. An optional ParSun throttle interface can be pre-wired to the
> motor. Control wiring is plug-and-play with the ParSun, or with just three
> 1/2" mounting holes for the included switches and potentiometer. The
> switches and pot can be mounted in any exposed area, but I would recommend
> keeping the ParSun covered when not in use to slow aging of exposed rubber
> cables.
>
> I invite your questions and comments. This design is constructed provide
> many, many years of reliable service, with the fastest wearing part, a
> double row sealed bearing (3305) resolving the prop shaft thrust,
> replaceable without disturbing the installed motor. The standard warranty is
> five years, full replacement, excluding over-voltage (<30vdc), reverse
> polarity, and shipping. Rebuilding damaged motors can be accomplished by
> returning the motor in the original shipping container. I am offering an
> unlimited lifetime warranty with the a-fore mentioned conditions on the
> first ten units, five of which are now ready to ship from Thunderstruck-EV.
> Contact Mark in Sales during business hours.
>
> Be Well,
> Arby
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

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