New Human Powered/Electric Gear Prototyping

Discussion in 'Propulsion' started by Carlazzomark, Apr 15, 2010.

  1. Carlazzomark
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    Location: Michigan

    Carlazzomark Senior Member

    Troy, Michigan, April 12, 2010 --- Marco Polo Boats, Inc. (MPB) of Troy, Michigan, USA, seeks boat builders and human powered boating enthusiasts to test prototypes of a new in-water gear assembly designed for human powered and electric powered boats.

    The prototype will be available this summer in four increaser ratios and two torque specifications. The range is intended to serve the leisure, rental, and performance markets.

    Qualified testers will be loaned a prototype in exchange for undertaking testing protocols over a 60 day period this summer. If a tester completes the protocol and adheres to program requirements, he or she will be given a gear assembly when production commences.

    “Marco Polo Boats is excited about this mechanism and its potential for inexpensive and energy efficient small boat propulsion,” said Mark Vermilion, president of MPB. “We want it tested in the real world by human powered and electric boat enthusiasts so that we can make improvements prior to production.”

    Qualified testers must provide their own water craft with front-end pedaling or electric motor, a connecting shaft, and propeller. Optimum input RPMs for the unit are from 50 to 100.

    The gear assembly comes in increaser ratios of 1:7 and 1:49 (each with a maximum torque of 157 lb-in), and 1:5 and 1:25 (each with a maximum torque of 200 lb-in).

    MPB seeks testing applicants according to the following chart:

    Human Powered Category
    Ratio Number of Units Max. Torque
    1:5 4 200 lb.-in.
    1:7 4 157 lb.-in.
    1:25 2 200 lb.-in
    1:49 2 157 lb.-in.

    Electric Motor Powered
    Ratio Number of Units
    1:5 2 200 lb.-in
    1:7 2 157 lb.-in.

    Interested parties should e-mail for program requirements.

  2. kach22i
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    kach22i Architect

    Sounds interesting, I'll pass this along.
  3. woodenmfv
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    woodenmfv DryRotHunter

  4. alan white
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    alan white Senior Member

    This is about a drive mechanism minus the power source, I think. Judging by the ratios, I'd guess it is a trochoidal drive using ball bearings instead of gears. The units would be small assemblies somewhat similar externally to the drives used on cordless drills, but internally, the principle is entirely different, but the same as the way a Wankel engine works.
    The 1:5 and 1:7 ratios appear to be single-stage units, and doubled they yield 1:25 and 1:49 respectively. I imagine they could also mix and match and get 1:35 too.
    Drives like this are incredibly efficient and smooth. Instead of gear teeth, which slide and make friction the power is transmitted through rolling surfaces only. This also make the drive almost noiseless and free of vibration due to a perfectly consistant pitchline velocity (normal gears especially when a bit worn tend to speed up and slow down the output speed due to the impossability of making absolutely perfect gear teeth.
    Here's a link that more or less explains the drive type I think they're talking about. bearing trochoidal drive&f=false
  5. Carlazzomark
    Joined: Oct 2006
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    Carlazzomark Senior Member

    Reply to woodenmfv

    The Lario boat on is not related to our new in-water gear system, although at some point we may try to attach this gear to an inboard electric motor.

    The 157-200 in-lb torque relates to the continuous torque the gear assembly can handle, not to an electric motor power source.

    Hope this helps,

    Marco Polo Boats, Inc.


  6. Carlazzomark
    Joined: Oct 2006
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    Location: Michigan

    Carlazzomark Senior Member

    Reply to Alan White


    You are correct in stating that this is a drive mechanism minus the power source. It is an in-water speed increaser gear assembly, with increaser ratios of 5, 7, 25, 49, and, yes, we could do 35.

    We can't go into details on what's inside, but the efficiency of the single digit increaser (5 & 7) is 98%, and for the double digit increasers (25, 35, & 49) it is 95%.

    I've attached a drawing of the assembly exterior. I actually just got the final parts today and was in the shop putting together the first prototype.

    Our hope is to provide an efficient & economical increaser assembly that can be attached to just about any type of boat and connected to a power input source, be that pedal (which in most cases would require a front-end twisted chain/belt or right angle gearing) or an electric motor. Think of it as the lower unit of an inboard/outboard motor, except on the inboard power side there is either someone pedaling or some type of energy efficient motor, either of which is provided by the end-user.

    The great advantage of this unit is that the rpm increasing happens just in front of the propeller, so that your front end power source (twisted chain, etc.) can be a simple 1:1 or 1:2, yet you still get tremendous output at the prop.

    Marco Polo Boats is also currently working on a front end pedaling source, but we wanted to make this lower end available to everyone as soon as possible. We need to test the prototypes first, hence our offer.

    Attached is a drawing with measurements along with the requirements if anyone is interested in the test program.


    Mark Vermilion
    Marco Polo Boats, Inc.


    Attached Files:

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