Page 1 of 4 123 ... LastLast
Results 1 to 10 of 32

Thread: Keystock

  1. #1
    Join Date
    Jan 2003
    Location
    On the Oil Coast,USA
    Posts
    16,778

    Lightbulb Keystock

    I have been seeing a lot lately here and other places on the subject of keystock and just thought I would put my two cents in,I started years ago using cold rolled square stock instead of keystock #1 its a lot cheaper,you can get six feet for the price of one #2 you don't have to file it, keys should fit by either pushing in or lightly tapping in anyway,if it fits too tight it will swell the shaft either side of the slot.#3 it is usually stress relived keystock is not,using it has made things nuch easier for me and the people I build things for.
    I just need one more tool,just one!

  2. #2
    Join Date
    Jan 2003
    Location
    Deep in the Heart of Texas!
    Posts
    5,645

    Question

    I think key stock is supposed to be a little softer isn't it? ... So that it shears instead of the shaft or gear. Down here on the farm, I'd hate to twist an axle or shaft just because I wanted to save $2 (or less). I just bought a piece of 7/8 key stock for $3.50. The shaft it goes to cost over $1,000 and the gear drive it fits into is over $6,000. If there was a jam, I'd hate to be buying new parts.

  3. #3
    Join Date
    Nov 2002
    Posts
    296

    Post

    Keystock can be made from brass, stainless, 1018, high carbon or several other types also.
    It all depends on the application. If you are looking for a light shear load, use brass.
    For most uses I like the zinc plated keystock. Plain steel can make it a little tougher getting things apart when it rusts up a bit.
    Even from McMaster-Carr the stock isn't that expensive.
    Les

  4. #4

    Post

    I read one time how a "farm hand" fixed a key that would shear every other day.
    He used a dowel pin you know tool steel case hardend. he said it never sheared a key again. yeah and it won't till the shaft twists it self off.
    Figure out why the thing is shearing the key in the first place then fix that. Most machines were made right to begin with who the heck was he to think he knew more then the people that built it.
    Kerry
    Rule #1 be 10% smarter then what you\'re working on.
    Rule #2 see Rule #1

  5. #5
    Join Date
    Apr 2003
    Posts
    9

    Post

    Les mentioned using zinc plated key stock. I sometimes work on fishing winches (salt water) and beside using zinc plated, put the "Never Seize" to it. I coat the shaft, the keyway, and the key after it's seated. It's a good idea to do this on any kind of machine that will be out in the weather or together for a long time.

  6. #6
    Join Date
    Jan 2003
    Location
    On the Oil Coast,USA
    Posts
    16,778

    Post

    Well it first dawned on me when I saw them supply it with new electric motors,the zinc plated stuff I hate with a passion,the zinc is usually about.003-.005"thick and is soft,it also causes galvanic action,I coat everything I assemble with never-sieze or paste wax makes disassembly a lot easier later.If you shear a key you are overloading the shaft in the first place,if it does shear it usually screws up the bore anyway.But I will still use it anyway because sometimes I cut 20 or so keys a week and I hate filing zinc off!
    I just need one more tool,just one!

  7. #7
    Join Date
    Jan 2003
    Location
    Deep in the Heart of Texas!
    Posts
    5,645

    Post

    I usually get the uncoated keystock. I've seen the coated in hardware stores and home centers but I don't use that stuff in anything that's important. It's not that hard to get the zinc off--all you have to do is heat it and burn it off.
    I had forgoten to mention before but most lawn mower engines have very soft keys in the flywheel. In case you hit a stump, it's supposed to sheer the key and spin the flywheel instead of twisting or braking the crank. (Of course this has never worked for me though.)

  8. #8
    Join Date
    Apr 2003
    Posts
    9

    Post

    Ken, DON'T burn galvanizing off anything! Zinc fumes are not good for you. Don't weld, don't burn anything galvanized unless you're outside in a stiff wind - and then only if it's absolutely necessary.

  9. #9
    Join Date
    Feb 2002
    Posts
    2,362

    Post

    Soft keys in lawnmowers flywheels. On the light duty, direct drive mowers with the potmetal flywheels- the actual flywheel is the blade. No blade? the "flywheel" splits when the engine fires. Been there, done it like five times in as many days. I kept telling Brother in law that he was not getting the "flywheel" seated. Then I made excuses about why my seating was no better, Bought so many used engines (just for the flywheel) that we sent sis to shop to buy another used engine (just for flywheel). Saleman says to sis "you with those two guuys that keep breaking flywheel? they could have bought a new engine chaeper by his time." sis says something like "can't buy their pride " saleman says "they ain't seating the flywheel right"> Brother in law figured it out- woke up knowing what we were doing wrong. So we put the blade on and no more problems. I have seen engines with cranks twisted when they hit a stone. Why did not the flywheel break? No idea! But it is hard to think that coming up to speed is able to snap a flywheel, and slowing down is not. Another of lifes mysteries. Any speculation?
    Steve

  10. #10
    Join Date
    Jan 2003
    Location
    Deep in the Heart of Texas!
    Posts
    5,645

    Post

    Nick - So that's what is wrong with me.... Oh yes, I know about zinc fumes.

    Steve - I've broken a few cranks in my days. Two on the same stump! At the time, lawnmowers were cheaper than having a stump cut out ($39 vs $200). I've also spun a lot of flywheels on B&S 5hp horizontal engines. I used to build these for go karts. Easy to get 10-12hp @ 5,000rpm, if you could keep the flywheel keyed. On the 20hp models, we used diferent cranks and a 16oz. flywheel. Never did loose one of those. Lost a few heads though! Kept blowing the casting out between the "two" plugs.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •