front rowing system for canoe

Discussion in 'Boat Design' started by jyoder111, May 3, 2011.

  1. Easy Rider
    Joined: Oct 2009
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    Easy Rider Senior Member

    Marc,
    It's 16.5 to 17" and I'm 5'10.5" tall. Hands and feet move the same distance as the line (rope) from the foot pedals is attached to the heel of the pedals and to the "D" ring that the hands pull on. So the feet apply power (pull) at the same point as the hands. The foot pedals move fwd under the power stroke pulling the lines around 2 pulleys just behind the rower and then forward pulling the D ring handles back. D rings are held by the hands and attached to the oar 17" out from the oars fulcrum point in the center of the boat. See Ron's website at front rower.com. One can row w feet only as well as arms only. I think the price is $1850 so it's not cheap but it's very well built. All the wood is varnished Cherry.
     
  2. magnus
    Joined: Mar 2010
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    Location: minnetonka minnesota usa

    magnus Junior Member

    Ron and I have similar mechanics in our bow facing rowers, I believe, except that he decided to pull from the middle and I oppted for pulling with linkage from a forward position. I could make arguments for either position. One advantage bow mounted oars may have is the gearing adjustment. From hull pivot to oar tip I have 86.5". I have multiple through holes in my foam filled alloy oar shafts which I have currently set at 21.25" out from the hull pivot for the leg drive line and 24.25" upper body drive. So I like a 15% differential in gearing between legs and arms, I think . I just got this out after years of nonuse so I may change my mind. Five knots was comfortable with this gearing.
     
  3. Jeremy Harris
    Joined: Jun 2009
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    Jeremy Harris Senior Member

    I've nearly finished my front rowing system, which is basically a modern version of the system used on duck punts back in the mid to late 1800's. Here are some photos of the unit minus the handles (I'm still waiting on some bar to turn these up).

    [​IMG]

    This is the position more or less at the catch.

    [​IMG]

    This is the position more or less at release.

    [​IMG]

    The system allows the oars to go over-centre so that they can be shipped properly.

    [​IMG]

    Here's a close up of the linkage, which uses some cheap stainless steel rod ends I bought from ebay for the link pivots. The main bearings are oilite bronze bushes running on stainless steel pins.

    [​IMG]

    The alloy plates that carry the linkage and vertical pivots rotate around the horizontal axis on these oilite bushes, held in an alloy block that's bolted to the end of the outrigger.

    The boat is the SOF one in the "Beautiful skeleton" thread.

    Jeremy
     
  4. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Jeremy, is it fixed or sliding seat? I'm seeing only 2' stroke.

    At least the angle of the handles looked pretty reasonable at the extremes unlike some double jointed rigs.


    I see you've also set it as "high geared" (short stroke/long swept).

    Why not just shove some dowels into the pipes for handles, or even whittle down a tree branch?
     
  5. Jeremy Harris
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    Location: Salisbury, UK

    Jeremy Harris Senior Member

    It's fixed seat (at least for the time being). The ratio of handle angle to oar angle is 4:5, so there is a 20% increase between handle and oar movement. I've arranged the pivot points and link length to get a system that accelerates the oar from the catch to the release, as my current thoughts are that this makes sense in terms of accelerating the boat (although I may well be wholly wrong on this).

    I've tried to keep the handle angles reasonable, because I'm not as young as I was and would rather pull hard and short, without flexing my wrists too much, than pull with a lower force over a wider angle.

    I would rather fit the proper handles before I get to row it, as it needs some counterbalancing, by adding weight inboard, to make rowing less hassle. With luck I may get to try it on the water the weekend after next.

    Jeremy
     
  6. magnus
    Joined: Mar 2010
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    magnus Junior Member

    Jeremy,

    Beautiful work, it will be good to hear how you like it. It looks light, would you like to share the all up weight with us?
     
  7. eyschulman
    Joined: Jul 2011
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    eyschulman Senior Member

    For what its worth I think the front faceing rowing is getting overly complicated here. I have and still do front face rowing. On larger boats I like to stand and push my body weight forward into the power stroke on canoe types lateral extensions for oar locks are in order here I sit and push my arms and body forward into the stroke or will do the fishermans single alternating stroke. It works but never close to as efficient as the standard rear faceing methods moveing seat or not. The most efficent system I have ever seen or used is the fixed seat moving oar rig. Here the butt and most of the body weight stay in one place and there is little if any hobby horseing with a full lenght full power leg and arm extension stroke. I believe this system was outlawed for racing rigs(probably too good)
     
  8. Jeremy Harris
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    Jeremy Harris Senior Member

    Thanks for the kind words. The boat weighs around 15kg (about 33 lbs) but I haven't weighed the front rowing kit yet. My guess is that it adds another 5 or 6kg (around 10 to 12 lbs).
     
  9. Easy Rider
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    Easy Rider Senior Member

    Jeremy,

    It looks like some of my ultralight aircraft projects of the past.
     
  10. Jeremy Harris
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    Jeremy Harris Senior Member

    Good spot! My background was light aircraft design (as a hobby, before I switched to back to playing with boats again). The frame is built pretty much like an ultralight, light alloy tubes fastened together with stainless steel blind rivets, with epoxy/glass over foam for the stem and transom. There are some other pictures on the "Beautiful skeleton" thread.
     
  11. ancient kayaker
    Joined: Aug 2006
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    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Any more front rowing development or construction?

    It would be nice to know if anyone has made progress since last year. I'm over the health problems that have stalled me for the last couple of years but am still catching up with work in progress so I haven't cut metal yet.

    But I did do some calculations: for Squidley's curved rack concept the effective oar length is greater than the actual oar length by the amount Gearing/(Gearing - 1), so for a system with typical gearing of 3:1 the oars can be reduced to 2/3 regular length and still rotate through the same angle for a given stroke. This is an advantage over the conventional type shown at http://www.youtube.com/watch?v=Vs8qBExVAIA

    For the curved track concept the torque that must be reacted by the carriage running along the track has been a concern for some. The torque is equal to Y*Thrust where Y is the length from the track to the blade; it seems obvious now I've calculated it but it wasn't before! It is independant of the gearing ratio which simplifies calculations.

    As an example, for peak thrust of 10 lb (a pure guess) where Y = 6.5 ft the torque is 65; a carriage with cam followers spaced 8" apart would limit the force on the follower to a reasonable (IMHO) load of 100 lb. (1 kg = 2.2 lb, 1" = 2.54 cm)
     
  12. magnus
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    magnus Junior Member

    Jeremy,

    It would be great to hear how you feel about your project, what works and what you might change.

    Jim
     
  13. IMAC
    Joined: Mar 2015
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    Location: melbourne

    IMAC New Member

    front rower

    Hi Jeremy, Im very interested if your front rower system worked as well as it looked . How did it go. Im keen to build one.
    Ian
     
  14. Scott Gullion
    Joined: Nov 2020
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    Scott Gullion New Member

    did you ever get a solution to this?
     

  15. Scott Gullion
    Joined: Nov 2020
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    Location: Calgary

    Scott Gullion New Member

    any luck? you're asking the questions and seem to be on the same track I am.
     
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