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Thread: Attaching sprockets to motor shafts?

              
   
   
  1. #1
    Senior Member __Tango's Avatar
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    Attaching sprockets to motor shafts?

    So, all of my experience is with hub motors, so I've never dealt with attaching a sprocket to a motor shaft. I'm looking at the Revolt RV-120 Pro or RV-160 Short. These have motor shafts where I'd have to attach a sprocket. This motor normally has either a 15 or 20mm shaft with a slot cut out for some sort of set screw. I'm wondering if it's standard to find a sprocket with this type of connector. What other options do I have for setting up the sprocket?
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    What kind of sprocket do you want to use?
    Farm supply and industrial supply store tend to have sprocket hubs that slip on the motor shaft with a key.

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    That slot is called a keyway. The sprocket should have a matching keyway. The sprocket should have a set screw directly over the keyway to hold the key in place. Sometimes you can't find a sprocket with the same sized keyway. This is where stepped keys come in handy. The best way to affix a sprocket is with a taper-lock, if you can find one that fits your shaft, has the right tooth profile, count, etc. A taper-lock eliminates any play between the parts, which could eventually lead to failure.

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    Senior Member Hugues's Avatar
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    Taper-lock is good. But also make use of your keyway if you can, that's what I did, both system.
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    Check on YouTube for how the Taper-Lock and other tapered bushing systems work. They're far superior systems for attaching sprockets to shafts than the standard set screw over key system. If you do use the set screw system, use a bolt or nut on the end of the shaft to keep the sprocket from working its way off the end of the shaft.

    Sprockets are available from the power transmission supply houses, Grainger, McMaster Carr, and many others. Motorcycle chain sizes may vary from the industrial sizes, so you need to be careful matching chains and sprockets.

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    Seņor Member podolefsky's Avatar
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    If you can't get a taperlock in the size you need, you can use shaft collars on either size of the sprocket (as long as there is enough room on the shaft).
    - Noah Podolefsky -
    The GSX-E

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    Motor sprockets have 2 set screws, one holds the key in place (rotation control) and the other is to keep the sprocket from sliding on the shaft (linear control).

    In my ( some what limited ) experience, If the rear sprocket is aimed correctly, And the motor shaft is exactly perpendicular, the chain will keep the front sprocket centered on the shaft.
    "obstacles suck but challenges are fun"

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    Quote Originally Posted by Ken Will View Post
    Motor sprockets have 2 set screws, one holds the key in place (rotation control) and the other is to keep the sprocket from sliding on the shaft (linear control).

    In my ( some what limited ) experience, If the rear sprocket is aimed correctly, And the motor shaft is exactly perpendicular, the chain will keep the front sprocket centered on the shaft.
    In an ideal world, this would all be true. More often with dirt, water, rust, slight unavoidable misalignment, and time this is what can happen with non-taper bushing sprockets: https://www.google.com/search?q=bad+...eyway+&imgrc=_

    In my somewhat vast experience, I've never seen this happen with a properly installed taper bushing sprocket. My suggestion is to set up the final drive ratio with the cheaper set screw sprockets. You will probably be buying different sized sprockets to get it right. By all means, use an end bolt to cinch the sprocket (with spacers, if needed, as suggested by Noah) to the motor shaft. If there's any sign of set screws loosening or fretting corrosion (like this:http://club4ag.com/forums/viewtopic....16665&p=109765), you should seriously consider changing to a taper bushing sprocket like the Taper-lock design.

  9. #9
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    I used the taper bore system on my belt drive pulleys. I bought everything from Royal Supply, its all heavy industrial stuff but it works
    Mike Pipes
    - Currently under analysis paralysis.

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    Seņor Member podolefsky's Avatar
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    Quote Originally Posted by Ken Will View Post
    Motor sprockets have 2 set screws, one holds the key in place (rotation control) and the other is to keep the sprocket from sliding on the shaft (linear control).

    In my ( some what limited ) experience, If the rear sprocket is aimed correctly, And the motor shaft is exactly perpendicular, the chain will keep the front sprocket centered on the shaft.
    It might stay centered, but the set screws will inevitably fall out, followed by the key. I've had every set screw fall out, no matter how much thread lock and tightening I did. I don't know if it's because those industrial sprockets aren't made for high RPM or what.

    Shaft collars lock to the motor shaft, so with one on each side it will hold the sprocket and key in place. I used them instead of taper lock because with a #50, 12 tooth, 7/8" bore there isn't a lot of material in the sprocket. I've broken sprockets trying to use taper lock. Getting the torque just right would do it, but it made me nervous about the extra stress when a 12t is already pushing it.

    They look like this:

    shaft_collar.jpg
    - Noah Podolefsky -
    The GSX-E

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