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Step 12Wheel Mounting
Hey, since this IS a "hub motor", there ought to be a way to mount a wheel on it or something. You might have picked a wheel out already to build your motor within, or are building the motor to eventually mount a tire to.
Let's clear up some terminology first. The tire is what contacts the ground. The rim is what the tire is mounted to, just like in a bike or car. The hub is what the rim mounts to. We are building a hub motor.
It is perfectly reasonable to integrate "rim" and "hub" in a small motor. We will see that the integration was my choice for RazEr.
Wheel mounting generally comes in one of several flavors, just like everything else. The exact method you might end up using depends strongly on your available space and existing wheel specifications.
ý Car style. The hub is distinct from the rim. If you literally are building a hub motor for a car (why are you reading this?) then it offers the most flexibility in terms of wheel placement and choice. Welded or stamped studs usually emanate from one endcap so you can mount the rim.
ý Bike style. In the case of bicycle motors, the rim is still distinct from the hub, and radial spokes emerge from flanges on the case of the motor, usually the endcaps.
ý Scooter style. A degenerate case of the bike motor, the rim is small enough to be directly bolted to the endcap projections. The rim is still distinct and removable.
ý My style. Illustrated below in Figures 2 through 4, this just puts the tire (in my case, a chopped and screws push scooter wheel) directly between the endcaps, sitting on the motor can. Not serviceable without removing a motor endcap, which really constitutes taking apart the motor. Thus, RazEr's motor isn't very suited for public release.
ý A modified version of "chuxx0r style" is removable rings that are logical (but not physical) extensions of the rotor endcaps, which are now completely inside the can, and attach using radial screws. This means I can undo one of the rings, slip the wheel off, put a new one on, and reattach everything.
ý Just glueing rubber to the outside of the can. Yeah, it can be done. You'll make steamroller tires and you better be sure the glue is strong!
Wheel gutting
If you're building small motors like me, it's usually hard to find just "a tire" for the motor. You'll have to cut it out of another wheel.
This is a tricky machining operation because you can't fixture to rubber tires- they'll just deform. If you can securely clamp the wheel to a machine surface, then by all means, cut away.
ý If the wheel is sufficiently small, you can use a machininable fixture collet on a lathe to grip the entire outside at once. That will usually gain enough stiffness to let you cut the center out. These things are made up to 6 inches or so for common, import-grade fixtures.
ý Make a mandrel that bolts through the center of the wheel. Now you have the wheel secured by its strongest point.
Casting your own tires
Certainly an option, and for the truly hardcore DIY addicts, the most productive. I have no experience with urethane or rubber casting, so can only tell you to read Instructables more.
Let's clear up some terminology first. The tire is what contacts the ground. The rim is what the tire is mounted to, just like in a bike or car. The hub is what the rim mounts to. We are building a hub motor.
It is perfectly reasonable to integrate "rim" and "hub" in a small motor. We will see that the integration was my choice for RazEr.
Wheel mounting generally comes in one of several flavors, just like everything else. The exact method you might end up using depends strongly on your available space and existing wheel specifications.
ý Car style. The hub is distinct from the rim. If you literally are building a hub motor for a car (why are you reading this?) then it offers the most flexibility in terms of wheel placement and choice. Welded or stamped studs usually emanate from one endcap so you can mount the rim.
ý Bike style. In the case of bicycle motors, the rim is still distinct from the hub, and radial spokes emerge from flanges on the case of the motor, usually the endcaps.
ý Scooter style. A degenerate case of the bike motor, the rim is small enough to be directly bolted to the endcap projections. The rim is still distinct and removable.
ý My style. Illustrated below in Figures 2 through 4, this just puts the tire (in my case, a chopped and screws push scooter wheel) directly between the endcaps, sitting on the motor can. Not serviceable without removing a motor endcap, which really constitutes taking apart the motor. Thus, RazEr's motor isn't very suited for public release.
ý A modified version of "chuxx0r style" is removable rings that are logical (but not physical) extensions of the rotor endcaps, which are now completely inside the can, and attach using radial screws. This means I can undo one of the rings, slip the wheel off, put a new one on, and reattach everything.
ý Just glueing rubber to the outside of the can. Yeah, it can be done. You'll make steamroller tires and you better be sure the glue is strong!
Wheel gutting
If you're building small motors like me, it's usually hard to find just "a tire" for the motor. You'll have to cut it out of another wheel.
This is a tricky machining operation because you can't fixture to rubber tires- they'll just deform. If you can securely clamp the wheel to a machine surface, then by all means, cut away.
ý If the wheel is sufficiently small, you can use a machininable fixture collet on a lathe to grip the entire outside at once. That will usually gain enough stiffness to let you cut the center out. These things are made up to 6 inches or so for common, import-grade fixtures.
ý Make a mandrel that bolts through the center of the wheel. Now you have the wheel secured by its strongest point.
Casting your own tires
Certainly an option, and for the truly hardcore DIY addicts, the most productive. I have no experience with urethane or rubber casting, so can only tell you to read Instructables more.
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