Weed eater engine conversion

Discussion in 'DIY Marinizing' started by Ward, Jun 2, 2003.

  1. Erich_870
    Joined: Feb 2009
    Posts: 86
    Likes: 2, Points: 0, Legacy Rep: 29
    Location: Juneau, Alaska

    Erich_870 Junior Member

    Sounds like a sweet build. Can't wait to see some updates!

    Erich
     
  2. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    When I was messing around with small power DIY propulsion using the 1 HP Briggs and Stratton motor from my Lawn Chief motor mower I made my own props from various things such as auto fan centers of trucks and flat sheet steel plate or flat strip.
    I cut out the profile of one blade and used that for a patten for two three or four blade props. I bent each blade to the pitch I wanted to try and they worked just as well as a professional built prop and a lot cheaper. They were easy to repair and alter to try more or less pitch.
     

    Attached Files:

  3. Tillerman6
    Joined: Sep 2014
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Sagle, Idaho

    Tillerman6 Junior Member

    Brush cutter 49CC with Transmission available again?

    Guys,

    It seems that some 50cc brush cutter engines with gear reduction and clutch are now available on Amazon once again. I am not in a position to buy one, nor do I have any connection with the sellers or Amazon, but I thought I should mention it here and see if anyone can benefit from the information. Good luck!

    Earl White ewew921@gmail2.com

    Please let me know if you have one of these for your project and how did it perform, what kind of boat etc?

    http://www.amazon.com/gp/product/B0...pf_rd_t=101&pf_rd_p=1688200422&pf_rd_i=507846
     
  4. ben2go
    Joined: Jul 2008
    Posts: 181
    Likes: 4, Points: 18, Legacy Rep: 13
    Location: Upstate, South Carolina,USA

    ben2go Boat Builder Wanna Be

    Check it. http://directboats.com/gaspotrmo.html
     
  5. copterdoc
    Joined: Sep 2014
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: NW Illinois

    copterdoc Junior Member

    I finished the mount and built enough of a motor that I was able to prove the concept does in fact work.

    However, it's still not performing at a level that makes it "better" than the electric troller I'm relying on currently.

    I've got parts on order, and have my fingers crossed that I will have something that performs at a level worth using (and posting about) by next weekend.
     
  6. ben2go
    Joined: Jul 2008
    Posts: 181
    Likes: 4, Points: 18, Legacy Rep: 13
    Location: Upstate, South Carolina,USA

    ben2go Boat Builder Wanna Be

    I originally came to this thread looking for an ultralight motor for my boat.My Jboat has a weight limit of 320lbs.I was 230lbs.My trolling motor was 30lbs and battery was 65lbs.That put me over my weight limit.No more room for fishing gear or survival gear.I am loosing weight and down to 200lbs.I am back into looking at the production style trolling motors based on weed trimmers.
     
  7. copterdoc
    Joined: Sep 2014
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: NW Illinois

    copterdoc Junior Member

    After much disappointment and frustration yesterday, I made few late night tweaks and finally achieved some real success this afternoon.

    Speed was 5 MPH peak, with 4.2 sustained while bucking a 15 MPH headwind.

    When I got into weeds heavy enough to completely stop my troller, this thing actually pushed the canoe faster than it did on open water!

    Here's some footage.
    And I did warn you that this is very different.


     
    Last edited: Oct 21, 2014
  8. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    That look`s very impressive to me. I will have another look when my broardband speed is faster.
     
  9. copterdoc
    Joined: Sep 2014
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: NW Illinois

    copterdoc Junior Member

    I am VERY happy!!!!!
     
  10. Tillerman6
    Joined: Sep 2014
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Sagle, Idaho

    Tillerman6 Junior Member

    pretty good for the first try at this method! Looks like a double squirrel cage setup.

    I had no idea that this would work at all.

    Fun stuff.
     
  11. Erich_870
    Joined: Feb 2009
    Posts: 86
    Likes: 2, Points: 0, Legacy Rep: 29
    Location: Juneau, Alaska

    Erich_870 Junior Member

    That's pretty ingenious! Nicely done! I hope you'll consider making a video about how it works.

    Erich
     
  12. copterdoc
    Joined: Sep 2014
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: NW Illinois

    copterdoc Junior Member

    In order for something to BE good, it has both work good and it has to last a long time.

    I've got the first part down, (but it could be better) however I've failed on the latter.
    I smoked the $150 gearbox over the weekend.

    It just can't sustain operation with the amount of heat generated by that much load, for a significant number of hours.
     
  13. Erich_870
    Joined: Feb 2009
    Posts: 86
    Likes: 2, Points: 0, Legacy Rep: 29
    Location: Juneau, Alaska

    Erich_870 Junior Member

    It would still be an interesting video to see what failed. :)

    Erich
     
  14. Tillerman6
    Joined: Sep 2014
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Sagle, Idaho

    Tillerman6 Junior Member

    Computerdoc,

    Sorry about the gearbox. but you did try and that's what's important. Most people would just go and buy something or give up.

    So if something is overheating, you know the basic problem. Usually something is over stressed. Gearboxes can usually be upgraded for performance if you remove the factory lubrication and install 100% synthetic lubricants. This should really be done before you ever fire up the engine.

    The other thing that comes to mind is the clutch if there is one. That is the biggest heat generator if the propeller is seeing too much resistance and the rpm drops too far as a result. This causes a centrifugal clutch to slip because of the low rpm and that creates a runaway overheat condition.

    All this could be avoided if the engine can be operated at about 150% of the rpm where the clutch is designed to engage. Then also keep checking the housing around the clutch and gearbox to see if it is getting too hot.

    So basically you can't lug down the engine rpm too far and expect all the parts to stay happy.

    It would help too to see some pictures of your setup in detail. If yours is the dual squirel cage propellor you might be able to increase the "prop" rpm by reducing the size of the parts in the water. Not easy to do, but it';s better than burning up the gearbox?
     

  15. copterdoc
    Joined: Sep 2014
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: NW Illinois

    copterdoc Junior Member

    If you can show me how to record video of a Unicorn in flight, I'll promptly post a video of something that doesn't work, working.:confused::rolleyes:
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.