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Thread: Tough pulley removal - need suggestions

  1. #1
    Join Date
    Dec 2005
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    Tough pulley removal - need suggestions

    Iíve removed and pulled my fair share of pulleys over the years but Iím stumped on this one. The bandsaw is a 1980ís Vintage Centauro 600 CO, and to remove the motor the pulley needs to come off first.

    Problem is, I canít find a set screw that would lock the pulley to the key. Iíve looked everywhere about 6 times. Peeking on the motor side you. An see the shaft and the key/keyway. But no where is a hole for a setscrew, either on the inside part of the pulley or through the belt area. I tried pulling off the pulley with my big puller but didnít want to force it and break something.

    Any ideas? Just hit it with PB Blaster for a while and try to pull again?

  2. #2
    Bottom of the shive in line with the key?

  3. #3
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    Assuming you meant sheave, thatís the first place I checked.

  4. #4
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    Do you think it is a 2 piece sheave? From the pics you have very little room to work on that. Almost looks like it is a press fit one piece pulley. Sorry no right ideas for your dilemma!

  5. #5
    Heat it with a blowtorch?

  6. #6
    Join Date
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    Matt,

    I would measure the outside diameter of the motor shaft on the side between the pulley and motor. Then compare this to the diameter of the round center portion of the pulley on the outside of the pulley (side away from motor) to see if they are the same. If this second dimension is larger, then perhaps that small round area (the one that has a small hole in it) is actually a removable cap that if removed might reveal some sort of bolt retaining the pulley onto the shaft. This would mean that the center of the motor shaft is drilled and tapped for a retaining bolt. This is only speculation and my best guess based on the photos. Also - the first photo showing the exploded view seems to show that the keyway does not extend all the way to the outer end of the motor shaft.

    Otherwise - perhaps the pulley (sheave) is actually a press-fit onto the motor shaft and there is no retaining setscrew. As and aside: Early Chevrolet 283 (and some 327) engines simply used a press fit to retain the harmonic balancer/pulley to the nose of the crankshaft with a woodruff key to lock the balancer to the crankshaft nose rotationally. Later versions of the 327/350 engine added a retaining bolt. These versions had the center of the crankshaft nose drilled and tapped to accept the bolt. I know this because I have drilled and tapped some of the early crankshafts to accept a retaining bolt.

    David

  7. #7
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    I would not recommend heating with a torch (unless you are not worried about damaging the motor). It would probably be best to apply penetrating oil ("PB blaster") for several days and then use your large gear puller (or a bearing puller) to remove it. It does look like the end of the motor shaft (if that is indeed what I am seeing in photo 2) has a small hole for centering the nose piece of a gear puller. So I guess now that I think about it - the presence of that small hole might indicate that the sheave/pulley is indeed pressed on.

  8. #8
    If you're absolutely sure that there is no grub screw! Spray it with WD-40 or (brake fluid) for a couple days, then put the torch to it. Many fitters use Loctite as a setting compound. Only heat will turn this to a Caramel sludge to reduce the hold. As well only adding heat to the sheave in a uniform fashion quickly Will allow the sheave to grow. a puller Will work great in these conditions. Many many motor rotor are assembled this way.

    In some rare situations the key has a taper to it. Try to knock the key out a we bit before adding any heat. If the key is a taper fit there will be most definitely Loctite, and heat will be needed.
    Last edited by Matt Mattingley; 04-24-2019 at 7:00 AM.

  9. #9
    Join Date
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    use a bearing splitter or you will bend the pulley. the diagram does not show a setscrew so I think it is a taper shaft press fit.
    I would enlarge the opening to pull the motor with the pulley attached then look at it up on the bench. You can make a sheet metal shield later if needed to keep sawdust out.
    Bill D.

  10. #10
    Too often the mechanic applies heat in close proximity to the shaft because that's where it's stuck. Big mistake because that also heats the shaft plus the sheave can't expand because the outer diameter is still cold. Attach the puller with a reasonable amount of torque then apply the heat to the outer periphery of the sheave allowing the heat to conduct to the center portion. With this method I've had 4ft. diameter bull wheels release heating with 2 rose bud torches for bout 20 minutes, while the portion contacting the shaft is still at a temperature we could comfortably touch.

  11. #11
    It almost looks like you could unfasten the motor and then lift it up and angle it to slide pulley out the opening while still attached. That would make it a lot easier to work on. Of course, your photos don't show the motor side so I don't know if there is clearance to do this.

  12. #12
    Red stuff on the shaft behind pulley appears to be Loctite or some kind of adhesive? With no mechanical fastener on the pulley, perhaps the adhesive to "fasten" pulley was used . Use a puller set, preferably with a bearing separater tool behind the pulley. Is this pulley original to the machine?

  13. #13
    Join Date
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    Quote Originally Posted by Bill Orbine View Post
    Red stuff on the shaft behind pulley appears to be Loctite or some kind of adhesive? With no mechanical fastener on the pulley, perhaps the adhesive to "fasten" pulley was used . Use a puller set, preferably with a bearing separater tool behind the pulley. Is this pulley original to the machine?
    If red indicates Loctite, they put it everywhere. It's on the machine and the motor housing. A big puller and bearing splitter is the best option, but I bet it will take some heat as well.

  14. #14
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    Quote Originally Posted by Paul F Franklin View Post
    It almost looks like you could unfasten the motor and then lift it up and angle it to slide pulley out the opening while still attached. That would make it a lot easier to work on. Of course, your photos don't show the motor side so I don't know if there is clearance to do this.

    Paul you were right. I had to lift the motor and remove the motor mount, then tip the motor and barely got it out. So good news is the motor is out and I have easier access to work on the pulley.


    I needed to get the motor off to lighten it but also for clearance down the steps and around a couple turns and into my shop. Saw is stripped to bear frame now.

    Better pics are below. You can see that theyíre definitely is not a set screw anywhere. Shaft measures 28mm. I will likely stop by the hardware store and pick up some MAPP gas and put some heat to the pulley, on the outer parts, not the shaft as has been pointed out.
    Attached Images Attached Images

  15. #15
    Good to hear. But if pulling the motor was the only reason you needed to get the pulley off, I'd leave that sucker on there......

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