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Any Machinist out there that could help me with a chainsaw dyno?

Discussion in 'Chainsaw' started by chadihman, Mar 28, 2013.

  1. dozerdan

    dozerdan Account Hold

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    It looks like the weakest point will be at were the 1/2" to 1" transition is. Can you bore out the love joy to 5/8 or 3/4 and then broach it?

    Just make the darn thing.

    Try your local scrap yard, look for an axle from a rear wheel drive vehicle. That will give you plenty of material to work with. If you screw the first one up, no big deal, just try it again.

    This is almost as good as an oil or flippy cap thread.

    Later
    Dan
     
  2. kentuckydiesel

    kentuckydiesel ArboristSite Operative

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    Wtf? Its a shaft for a chainsaw dyno, not an Indy car.

    -Phillip
     
  3. Zombiechopper

    Zombiechopper Addicted to ArboristSite

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    that's kinda what I was thinkerin....

    I used to assemble fans for 50Hp electric motors that were used in Genset radiator setups. 12' diameter fan driven by a 50 horse motor and all that was used was standard 2" shaft that was bought in long lengths and cut down to fit the pillow blocks we were using. I know from cutting that stock and filing burrs that it sure as heck wasn't hardened and there was never a failure of a shaft that I ever heard of.

    The level of complexity assigned to this is getting a bit silly. Any scrap steel will work. If the key way is sloppy, just make an over size key and file it so it's a tight fit. This is not rocket surgery. :hmm3grin2orange::hmm3grin2orange:
     
  4. dozerdan

    dozerdan Account Hold

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  5. Dan_IN_MN

    Dan_IN_MN Addicted to ArboristSite

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    That's not a shaft! This is a shaft! This guy goes into depth on machining. He's a bit long winded. This part one of 9 or so.

    [video=youtube_share;z9SlGZMQWfM]http://youtu.be/z9SlGZMQWfM[/video]
     
  6. Zombiechopper

    Zombiechopper Addicted to ArboristSite

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    well, he has a nice wood pile LOL. And it was nice to hear the weather forecast in Nova Scotia 16 times.

    Is that for a boat or sumthin? He never really says what it's for.

    Anyways, after rethinking this I think the chainsaw dyno definitely needs differential heat treated 4140 shaft. Better double anneal it, HT, and triple temper down to exactly 32 rockwell. After that I think it is a strict certainty that it should be magnafluxed and certified by an engineering firm. Actually scrap that; we need to build a prototype and then do destructive testing to find failure points before fabbing the final product. Once we have certification from the transportation safety board and certificate of compliance from PETA, we can then apply for the NFA tax stamp.
     
  7. Dan_IN_MN

    Dan_IN_MN Addicted to ArboristSite

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    I did warn you that he was a bit long winded!

    It's for a large tree chipper. They broke the original shaft in half! I think it would be fun to work with him for a few days.
     
    Last edited: Mar 29, 2013
  8. Adirondackstihl

    Adirondackstihl Flyz, Fuel & Fotos

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    The material should be stress relieved before commencing any machining.:hmm3grin2orange:
     
  9. kentuckydiesel

    kentuckydiesel ArboristSite Operative

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    I'm with you on this. I have made a fair number of shafts for manufacturing and grain handling equipment. Never had anything that I didn't get to work pretty easily...and many of the elec motors running this stuff are running at 3450-3600rpm and putting out a great deal more power than a chainsaw.

    I would be glad to make it if I had the rest of the parts so I could test fit everything. It's just not a big deal.

    -Phillip
     
  10. FATGUY

    FATGUY Addicted to ArboristSite

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    unquestionably the best way to do it, but, not always practical or even possible. That's why we have tolerances that need to be properly addressed and communicated. I would use 1" TGP accuracy stock (my favorite flavor is 303SS) and then turn the 1/2" diameter 0.4995" with a TIR < 0.001".
    I don't blame the other guys for asking specific details. You don't want to be assembling this thing with a BFH. If you don't tell me exactly what to make, don't be surprised when it's not exactly what you wanted.
     
  11. Zombiechopper

    Zombiechopper Addicted to ArboristSite

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    BFH assembly is my favorite method. Don't take all the fun out of it! I used to call it the 'ford tool'

    Is this shaft built yet?A beaver could have gnawed one out by now
     
  12. Team FAST

    Team FAST ArboristSite Operative

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    You know, i was gonna knock this out because I was feeling charitable, but then I went out of town. Then I read all the posts by impatient curmudgeons who think they know better, and stop asking questions, just grab some re-bar and a bench grinder and a big freakin' hammer and go at it. Nevermind that he wants to fit bearings and keys. Nevermind that I have pride in parts leaving my shop are always to print and if the print is correct than they can rely on my ability to make it correctly. So, nevermind. I have plenty of projects.:msp_mad:
     
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  13. Bob Wright

    Bob Wright Addicted to ArboristSite

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    Or just a lathe and use it like a mill. I do it all the time. Here is how i make sure the shaft is on center with the cutter. I put in a center and press the part up against the center with my steel rule pinched in between. If it leans to the right at the top its too low. If it leans to the left its too high. If the rule is plumb its just right. It works on a mill or drill press also except the rule will be flat and the ends will tip down, so crank it until the rule lays flat.
    [email protected] if you still need it...Bob
     
  14. LegDeLimber

    LegDeLimber Addicted to ArboristSite

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    I was going to say check out the lindsay publications books,
    but I just looked at the site and he's shutting it down to retire.

    One of My favorites in those old books
    had a pic of a guy holding a lit match to the fuse of a section of dynamite
    which was packed into the oil hole of a journal of a large crankshaft.

    It was an "old school" method of getting that broken drill bit out.
    ("hey boss, can we order some nitro and try it for getting out broken taps!?)

    there were a lot of handy gadgets, tooling ideas
    and methods of getting things done in those books
    that could be built on a low budget and build it with what you've got
    yet would get a job done.

    edit: actually found a patent listing for the bit blasting method.
    http://www.freepatentsonline.com/2429967.html
     
    Last edited: Apr 2, 2013
  15. Bob Wright

    Bob Wright Addicted to ArboristSite

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    I posted again at 4:30 am after my 2 am but it didn't show up. Here is a a few things i though of. Use a good grade of tool steel like WH or 1144 Stressproof don't just use any old steel you need some strength where its turned down. Increase the 1/2" turned down to 5/8" for some more strength even if you have to get a bigger lovejoy or bore yours and rekey. Plus where its turned down add a radius where the turned down meets the 1" for some strength in the corner. Just my thought and an easy project if you need it done...Bob
     
  16. kevin j

    kevin j Addicted to ArboristSite

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    Are you going to cradle mount the saw engine and measure the torque reaction that way, or measure the torque on the fan/alternator/ pump you are driving?

    I think, given the amount of torque a saw engine puts out (like a couple of ft-lbf), that too much will be lost in the drive and bearings to try and measure the output end. It would compare two different engines, but not be an absolute meausred torque or hp value number. I think it will have to measure the reaction of the saw to be effective.

    Shaft torque certainbly won't be an issue. Stiffness may be, to prevent whip and vibration at certain speeds.

    Madsens used to have an air dyno but I don't know more than seeing a picture 15 years ago.

    I would REALLY like to see this succeed and see some actual numbers measured with porting or mufflers or other mods. Really like to know how much is performance and how much is noise. It sure was that way in the motorcycle world for a long time.
    You realize it may be like feeding a stray puppy: once this works you will have all sorts of friends asking to just check this will ya.... Sure, for a fair price.
     

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