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Unconventional Sawmill Build

Discussion in 'Quitters' Club' started by ITLKSEZ, Oct 29, 2021.

  1. Nov 14, 2021
    Fireball

    Fireball Well-Known Member 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Pullman, WA
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    As long as it sticks out past the wood, you could put a bulkier ball bearing/sprocket out there.
     
    ITLKSEZ likes this.
  2. Nov 14, 2021
    Lockman

    Lockman OK.....Now I Get It . 2022 Sponsor 2021 Sponsor 2020 Sponsor

    White City, NY 14617
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    When ripping with a circular blade , ones blade should not penetrate more than 3/4" past the thickness This allows less resistance drag on the blade & motor . :study:
    This is different physics though......So I'm out :confused:
    Signed,
    Cliff Clavin
     
  3. Nov 14, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
    Joined:
    Aug 13, 2015
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    Aaaaaaaaand… it’s dead. :lol:

    Like my jeep in Moab, the part that I’d feared would fail has failed, but this time, I don’t have a spare and I’m not sure it’s worth making another one.

    I’ll explain later when I have time.
     
    Fireball and SFaulken like this.
  4. Nov 14, 2021
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Hills of NH
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    It's not dead, it's just resting... pineing for the fjords...
     
    Twin2 and dozerjim like this.
  5. Nov 14, 2021
    hudsonhawk

    hudsonhawk Well-Known Member 2020 Sponsor

    North Texas...
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    That wouldn't vroom if you put 4 million volts through it.
     
  6. Nov 14, 2021
    Buildflycrash

    Buildflycrash Blind and Dirty 2022 Sponsor 2020 Sponsor

    Gulf Breeze FL...
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    That seems like a lot of work to stop already.
     
  7. Nov 14, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
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    Ok, so here’s the dilemma. There was one part of this build that I purposefully left out of public view, because it was a bit of a hack job just to get me running.

    I got a 7 tooth rim sprocket from the tractor store for a chainsaw.

    [​IMG]

    The ID of this piece was ~22mm and had teeth to fit over another cog. It is super-hard material that my carbide burrs wouldn't even touch. I had to grind it out to the shaft’s diameter of 25mm with a stone in the die grinder, then cut a tiny groove in it for a makeshift key out of 1/4” round stock. The material at the keyway was so thin, I thought for sure the fail point would be there - a split at the thin point at the "key."

    Well, the integrity of the sprocket turned out to be adequate, but the sprocket was so thin, the teeth of the chain now protruded deeper than the depth of the sprocket, riding on the shaft, and not allowing a tight mesh inside the sprocket. This little bit of interference became the problem. The teeth wanted to ride up on the sprocket and skip if the chain wasn’t kept tight.

    Over the course of yesterday and this morning, they skipped enough that it stripped out the sprocket to the point that it would no longer grab.

    And here’s the rabbit hole:

    I can get a 25mm keyed sprocket that would fit this engine perfectly, but it's 11 tooth minimum (57% increase!) and .404 pitch. That would be way too big of a chain and too fast for this engine, so I would need a bigger engine. A bigger engine’s torque will put too much stress on the other weak point, the aluminum track. When I bought the aluminum, I had laser focus on the straightness it offered, but I hadn’t put enough thought into just how much torque would be transferred to it. It’s marginally strong enough as-is. It has quite a bit of flex under torque.

    So a bigger sprocket needs a bigger chain which needs a bigger engine which needs a stronger track.

    And that’s where I’m at: upgrade none, or upgrade all. Upgrading everything would nearly triple my investment in this. A .404 sprocket is $80-120, a decent bar is $100 minimum, rip chain is $50, engine is $50-100, and an I-beam is probably $150 if I can find what I need at the yard.

    Here’s how much I got done before it quit (include the three whole rips I cut up to make the stickers).

    [​IMG]
     
    47v6, Norcal69, dozerjim and 3 others like this.
  8. Nov 15, 2021
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Hills of NH
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    If I'm reading this right, what about turning down the shaft of the motor, to fit the 22mm sprockets?
     
    Fly Navy likes this.
  9. Nov 15, 2021
    Lockman

    Lockman OK.....Now I Get It . 2022 Sponsor 2021 Sponsor 2020 Sponsor

    White City, NY 14617
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    I admire your Spring Pile......
     
  10. Nov 15, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
    Joined:
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    If I was in love with this engine, I’d probably go that route, but tearing down the engine to get the crank out to a machinist sounds like a lot of work. The engine is a bit temperamental with not enough flywheel weight (stalls without warning under load), and starting it with a drill each time is a pain.

    For now, I’ll probably try the same process with an 8-tooth sprocket, which *should* leave enough meat to avoid shaft interference with the chain. Hopefully the motor will have enough snot to turn it since it’s only a 14% increase.

    Long term though, the flex in the aluminum will need to be addressed if I’m going to keep this thing for any real production work. Sourcing trees won’t be an issue; my neighbors are getting wind of this and are offering up all their standing dead trees that they don’t want to deal with.

    I have a hunch that this thing could really plow through some wood if set up properly. Before (and probably the reason) it died, I filed down the raker teeth a little to get a more aggressive cut, and it easily doubled the cut rate, but the power suffered, and the flex in the aluminum was horrible due to the added bite. With all the aforementioned mods, this thing could be a monster.
     
    Fireball likes this.
  11. Nov 15, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
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    Aug 13, 2015
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    Plot twist! The sprocket is fine. It sheared the lame key.

    [​IMG]

    Also, I found the reason the bar tip was melting. :lol: I took the chain off and part of the sprocket fell out. The rest is missing. I’m wondering if the missing piece jammed and was the cause of the sheared key.

    [​IMG]

    I’ll grab another cheap bar/chain and put this thing back together just to finish my pile of logs. I’ll work on accumulating parts for a rebuild.
     
    tomasinator, 47v6, 73 cj5 and 2 others like this.
  12. Nov 15, 2021
    duffer

    duffer Rodent Power

    Bozeman, MT
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    Sep 17, 2009
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    hmmmm-it died on the 13th slab
     
    Walt Couch and ITLKSEZ like this.
  13. Nov 15, 2021
    SoCalNickG

    SoCalNickG Member 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Los Angeles, CA.
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    On the 13th! What time did it die?
     
    ITLKSEZ likes this.
  14. Nov 15, 2021
    jeeper50

    jeeper50 jeeps 'till I die

    Gawja
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    Dec 20, 2007
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    765
    What an awesome project saw!!! Keep up the great work.
     
    ITLKSEZ likes this.
  15. Nov 15, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
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    I’m back in business. I dug out an old bar from storage and it fits the rip chain! It’s a shorter bar, but I made the bar mount with a ton of adjustment; it just mounts further from the shaft. Shaft to tip is nearly the same as the old bar (the Stihl bar is wider, so I lost about 1/2” of length).

    [​IMG]
     
  16. Nov 15, 2021
    Snoops

    Snoops If I could get over the vertigo, I'd be done! 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Idaho
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  17. Nov 15, 2021
    Lockman

    Lockman OK.....Now I Get It . 2022 Sponsor 2021 Sponsor 2020 Sponsor

    White City, NY 14617
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  18. Nov 15, 2021
    dozerjim

    dozerjim Member 2021 Sponsor 2020 Sponsor

    western New York
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    Are you just dripping oil on the chain or pushing it through internally,could be the reason for sprocket failure....could you put oil in the bar and pressure the tank with air to push the oil through ?
     
    Lockman likes this.
  19. Nov 15, 2021
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Hills of NH
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    Me, I'd just start the engine and hold a file against the shaft. You (being better at rocket surgery) could probably rig a lath tool holder.
     
    Fireball likes this.
  20. Nov 15, 2021
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Post Falls, ID
    Joined:
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    It’s just dripping with gravity feed, but it’s definitely getting enough. It slings it everywhere. In fact, I just moved this thing to behind the shop at lunch because half the shop driveway is now covered in oil. :whistle:

    [​IMG]

    I think it failed because (1) as I mentioned, it’s pulling all the torque across it, and (2) that bar is cheap, inferior garbage. The nose sprocket on this Stihl bar is huge in comparison.

    You’re giving this engine a lot of credit. It vibrates like a jumping jack! :D
     
    73 cj5, SFaulken, Twin2 and 1 other person like this.
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