COOT Amphibious ATV restoration

  1. knighty Member

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    1,604
    Location:
    Sunderland
    is the rubbish steering / wanting to go in a straight ling not because it has no diffs? all the wheels turning the same speed makes it want to go in a straight line?

    for the duff worm drive the drive/input shaft looks ok, I'm guessing the cog underneath has worn away? - I've had worm drive gearboxes like that on mincers do the same... normally because of a duff bering throwing the drive shaft out of line. mine have all been phosphor bronze, £700 a time to have one made :-o
     
  2. CompoSimmonite Member

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    4,082
    Location:
    Werrington, Stoke-on-Trent
    IMO best to leave cutting out rot until after sandblasted and you can properly assess what needs repairing
     
  3. armalites Member

    Messages:
    3,657
    Herefordshire
    I spoke to these guys a few years back and they seemed pretty good.

    https://www.hewitt-topham.co.uk/
     
  4. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    All wheels are driven at the same time the worm drive bevel boxes give it much higher ground clearance but mean it can only be driven off road otherwise lots of stress in drive train, 4 wheel steer should make it easier to get out of ruts etc

    Sorry should of said thats not my one i'll take a pic of it later it was left in the hull as bearings went before i bought it . Was very rusty and cant see it being usable now
     
  5. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    Great they look promising , I think there are a few engineering firms near me i might see what they think too
     
  6. chris pruteanu Member

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    632
    Location:
    ROMANIA
    Look for microcar lombardini engines, diesel, 2 cyl and 16 bhp water cooled engine which has a variator/varistor to go 2 wheel drive but i am sure a 4 wheel drive system can be implemented as well. Some italian goldini tractors have a 4wd system that bolts to a lombardini engine... Quite easy to retrofit and the engine os self contained with all bits...
     
  7. bricol Member

    Messages:
    627
    N.Yorks, UK

    Hewitt and Topham, who used to be in Keighley, were bought by Renown Gears a few years ago. I'm working with Renown / being educated on gears/profiles/materials on a fairly major project involving Newcastle Uni Design Unit Gear Technology and the government, and they know their stuff! They are gear people with massive knowledge, who happen to also make some general engineering stuff, rather than the other way around. If they don't know, I reckon it can't be done ;).
     
  8. Migmac

    Migmac Member

    Messages:
    2,937
    Location:
    Kintyre. Scotland
    looks a fun wee machine.
     
  9. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    Im hopefull it can be done otherwise the project stalls at first hurdle tbh, the other one i need to restore has ok gears i believe but its mine i want to get done too. There is a guy in the USA that makes replacements but not cheap
     
  10. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    this is my worm gear looks fudged to me

    20190129_215728.jpg 20190129_215738.jpg
     
  11. knighty Member

    Messages:
    1,604
    Location:
    Sunderland
    that looks fine to me... those bits are hardened... it's the gear is meshes with that takes all the wear and tare / any damage
     
    slim_boy_fat likes this.
  12. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    Really you think the divots wont matter ? if thats the case im a happy chappy

    I really dont want to damage the gear it meshes with as thats the expensive one , mine looks ok they are £350 to get a replacement :doh:

    coot gears2.JPG made from bronze
     
    Rannsachair likes this.
  13. knighty Member

    Messages:
    1,604
    Location:
    Sunderland
    give it a good clean up and see what it looks like.... as long as there's no sharp bits to scrape/grind the other gear I'd still use it

    plenty of oil in the gearbox when you fill it.... I always put in more than the fill level - the ones I've worked with are made for splash lubrication, the bottom edge of the big gear is only just in the oil level so as it spins it scoops up oil and spreads it around... oil level is set so it only just picks up a little bit.... I'd rather lose a fraction of efficiency and have plenty of oil in, to me it's better than the change of running low on oil, and it makes sure plenty is splashed over the bearings etc. too


    EDIT: looked at the photos again, I think if you have a wire wheels on a grinder or drill it'll clean most of that up good as new
     
  14. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire

    Cheers for advice , i will try to get a better picture later as to me it feels really rough but like you say if i can make it smooth oil will do its job
     
  15. bricol Member

    Messages:
    627
    N.Yorks, UK
    I have to say, unless it's the lighting, that gear, hardened or not, looks knackered! Not worn maybe, but rust, pitted, corroded. If it is, it will cause vastly accelerated wear on the other - which looks to be the sacrificial one anyway. Attempting to smooth it out will Mildred up the tooth profile even more, and cause more issues.

    Yes, it's run and drive, but . . .

    With a few measurements, you should be able to work out what DP that is, whether it's corrected or not, and get some idea of the cost of a replacement.
     
    8ob likes this.
  16. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    I will try to take a better photo as i think the ones above make it look better than it is , funnily enough its mostly the steel gear not the bronze one that wears much like on a rover v8 were the alloy rockers wear out the steel shaft ( a common fault). Spoke to my friend today can hopefully get one made if the other one is good enough to copy
     
  17. Pigeon_Droppings2 Member

    Messages:
    1,575
    Location:
    london
    Guess it's a bit like small tyres on cars wearing out quicker....the smaller gear is doing many more rotations I think for each rotation of the larger gear so maybe thats why it wears quicker?
     
  18. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    yeah the axles are 18:1 so i guess thats part of the reason it wears the bronze gear less
     
    Pigeon_Droppings2 likes this.
  19. dieselsamurai

    dieselsamurai Too many projects not enough time!

    Messages:
    271
    Location:
    Hampshire
    Not a toy

    coot-articulating-atv-3.jpg
     
    Pigeon_Droppings2 likes this.
  20. HopefullySoon

    HopefullySoon Member

    Messages:
    510
    Location:
    Heywood
    Depends on your definition of toy .
     
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