8" Pneumatic Wheel (am-0970)
Product Overview:
Here is a high-traction wheel which includes a grippy rubber tire, an pneumatic inner tube, and a strong plastic hub. These parts are shipped to you in kit form. The unique aspect about this product is the competition-ready hub. The hub accepts any 200x50mm tire and inner tube, 1.125 inch (outside diameter) ball bearings (2 per wheel are needed), and the mounting holes needed to install hardware to be sprocket-driven or hub-driven. This wheel ships as a separate tire, inner tube, and hub halves. Assembly is required.Important Notes:
- Diameter: The nominal diameter for this wheel is actually 7.65 inches when inflated normally.
- Tube pinching: When assembling the tube within the two hub halves, be careful not to pinch the tube rubber between the plastic hub halves. If assembled with the tube pinched between the hub halves, the tube may puncture and leak.
RPM Rating and notes:
These wheels are designed to be propulsion wheels for driving a robot or wheel chair. The design intent is to be contacting the ground, being driven by a gearbox at a maximum speed of approximately 500 rpm (which results in 17 feet/sec).
Within some applications, this wheel has been used as a shooter of objects, spinning at a very high rpm. For these applications, a higher rpm shows that the wheel may wobble, since the valve stem is mounted off to one side of the center of the wheel hub. We have seen properly balanced wheels, using securely mounted hardware (longer screws, washers) that can handle 5,000 rpm. When spinning this wheel at speeds up to 5,000 rpm, please take proper safety precautions.
Specifications:
- Diameter: 7.65 inches
- Width Across Middle: 1.8 inches
- Bore: 1.00 inch thru hole, with 1.125 inch x 0.375 inch deep bearing pockets
- Bolt Pattern: 6 holes, 0.20 diameter on 1.875 inch diameter bolt circle
- Body Material: black polycarbonate
- Load Capacity: 120 pounds
- Maximum inflation pressure: 35 psi
- Coefficient of Friction, Forward/Backwards on tight pile carpet: 0.93 (fully inflated)
- Coefficient of Friction, Sideways: (to be determined)
- Weight: 1.13 pounds
- Tread Material: gray rubber
- Tread Width: 2 inches
- Valve Stem: The valve stem may stick out up to 0.375" from hub
- Tire for 8 Inch Pneumatic Wheel (Metric Size 200x50mm)
- Inner Tube for 8 Inch Pneumatic Wheel, with 90 Degree Stem (for 200x50mm Tire)
- Hub Assembly for 8 inch Pneumatic Wheel, which includes two (2) black plastic hub halves and six (6) 4-40 x1 Pan Head Phillips thread rolling screws
- Bearings
- #10 Screws and Nuts Needed to Mount a Hub (2 Inch Long Screws are Needed) or a Sprocket (2.25 Inch Long Screws are Needed)
- Aluminum Hub, if Driven by a Shaft
The hub halves are held together with the #4-40 screws. This wheel can accept #10-32 screws for mounting sprockets or hubs, but these are NOT included since different length screws are needed to mount hubs or sprockets. These #10 screws can be mounted to the included 1.875 inch diameter bolt circle. The hub halves need to be assembled together so that the valve stem clearance holes line up. Locating features are present for easy alignment.
Usage:
With Axle and Hub:
- In order to drive this wheel with a hub, use Hardware Kit 11, which includes #10-32x2 screws (6) and #10-32 nylock nuts (6)
- In order to drive this wheel with a plate sprocket, use Hardware Kit 12, which includes a 550 Sprocket Spacer, #10-32x2.25 screws (6) and #10-32 nylock nuts (6).
- Two (2) bearings are needed for this wheel, if being driven by a sprocket. Use bearings with a 1.125 inch outer diameter. No flange is needed on either of the bearings.
- If you want to let this wheel spin without being driven, you will need to install two (2) bearings with 1.125 inch outer diameter.
