Data Sheet

ManualsBrandsParallax ManualsBrushed DC MotorsParallax Aluminum Motor Mount & Wheel Kit

Web Site: www.parallax.com

Forums: forums.parallax.com

Sales: sales@parallax.com

Technical: support@parallax.com

Office: (916) 624-8333

Fax: (916) 624-8003

Sales: (888) 512-1024

Tech Support: (888) 997-8267

Motor Mount and Wheel Kit –AL and –MP

–AL (#28962, aluminum) and –MP (#28963, molded plastic)

Each kit includes a 36-position Quadrature Encoder Set (#29321)

The Parallax Motor Mount and Wheel Kit –AL (aluminum) and –MP (molded HDPE plastic) are complete

mechanical drive systems for sturdy and robust mid-sized mobile robots. Each kit is comprised of two

independent drive assemblies that are mirror images of each other. Each assembly contains a right-angle

worm-drive gear motor, axle and ball bearing unit, a six-inch pneumatic tire with tube, and an integrated

encoder system that provides feedback to the microcontroller or processor of your choice.

This kit is designed for direct compatibility with our Arlo Robot Base Kit (#28960). It can be mounted to

your own custom robot platform using the pre-tapped holes in the machined 6061 aluminum mounting

blocks (-AL version) or in the pre-drilled holes on the injection molded High-density Polyethylene (HDPE)

mounting blocks (-MP version). These kits are not backwards compatible with the previous Motor Mount

and Wheel Kit with Position Controller (#27971). Please see the Product Compatibility section, page 13.

Features

Both drive systems

 Conveniently located mounting holes for

easy mounting to the Arlo Robot Base

Kit or your own robotic platform design

 Rugged pneumatic tires well-suited for

indoor and outdoor terrain

 Powerful and strong, yet light weight

Aluminum drive system (#28962)

 Powerful worm-drive DC gear-motors

mount on precision machined 6061 solid

aluminum Motor Mount Blocks

 Able to carry up to 60 lbs. of payload

HDPE drive system (#28963)

 Powerful worm-drive DC gear-motors

mount on precision injection molded

High-density Polyethylene (HDPE) Motor

Mount Blocks

 Able to carry up to 20 lbs. of payload

Encoders

 36-position Quadrature Encoders

provide up to 144 pulses per revolution

 Dual-signal, out-of-phase outputs

indicate direction

 Pulse widths indicate speed; number of

pulses indicate distance traveled

 Easy to integrate with your robotic

system designs

Key Specifications

Drive system

 DC Motor nominal operating voltage:

12.0 VDC

 No load current: approx. 1.50 A

 1.5 lbs. per drive assembly (two

included in this kit)

 Approx. 100 RPM @ 12.0 VDC, 1.50 A,

no load

Encoders

 Power requirements: 2.5 VDC @ 3.5

mA, 3.0 VDC @ 5.0 mA, 11.6 mA @

5.5 VDC max.

 Communication: dual-channel high/low

pulse output

 Dimensions: 2.0 x 1.1 x .25 in

(5.1 x 2.7 x 0.6 cm)

 Operating temp: 32–158 °F (0–70 °C)

Summary of content (13 pages)

PAGE 1
Web Site: www.parallax.com Forums: forums.parallax.com Sales: sales@parallax.com Technical: support@parallax.
PAGE 2
Bill of Materials for #28962 (Aluminum) Part # 750-90005 750-90006 29321 34030 34015 34016 34031 700-00100 710-00015 710-00031 710-00105 713-00030 721-00006 724-00001 725-00023 725-00024 Description Motor, 12 VDC (left) Motor, 12 VDC (right) 36-position Quadrature Encoder Set (contains 2 encoder assemblies) Motor Bearing Block 2 Aluminum Wheel, main rim – 6061 Aluminum Wheel, rim ring – 6061 Aluminum Robot Drive Axle 2 1/8 x 1” Roll Pin Screw, #4-40x1/2”, FH, SS Screw, M6,1 mm x 50 mm SH, Black Screw, #1/4
PAGE 3
Step 1: Axle Align the axle’s socket with the motor’s square drive shaft and press-fit it into place. Although the axle is precision machined to fit with the motor shaft, sometimes the axles will slide on effortlessly, or they may require a very gentle tap from a non-steel hammer to seat them as shown below. This is due to manufacturing tolerances on the motors. When you first put the axle on the shaft it may seem loose and wiggle around a bit…this is normal.
PAGE 4
Step 2: Encoder Disk Next, remove any debris from the internal fins on the encoder disk (a toothpick, fingernail or tiny screwdriver work well). Slide the encoder disk onto the drive shaft. The internal teeth on the disk will deform slightly and grip the shaft. Step 3: Bearing Slide the bearing onto the drive shaft. Copyright © Parallax Inc. Motor Mount and Wheel Kit -AL(#228962) –MP(#28963) v1.
PAGE 5
Step 4: Bearing Block Insert the motor and axle assembly into the Bearing Block. The Bearing Blocks are interchangeable, and therefore can be used on either side of the device. Be certain that the bearing is completely seated within the cavity – it should be a very snug fit. Step 5: Bearing Block and Drive Pin Insert the drive pin into the axle. Use a non-marring hammer (or be very careful with a regular hammer), and tap it in gently. It should be a “friction” fit. Copyright © Parallax Inc.
PAGE 6
Step 6: Bearing Block and Axle Assembly Using (3) 50 mm hex-head socket screws, and (3) 1” x 0.5” standoffs, attach the motor/drive axle assembly to each of the motor bearing blocks as shown. Step 7: Encoder Cables Plug the encoder cables into each of the encoder boards as shown. Be sure to match the wire color with the B-R-W color-coding on the boards. The white wires will be adjacent to each other in the center of the connector. Copyright © Parallax Inc.
PAGE 7
Step 8: Mount Encoder Boards Carefully mount the encoder boards in the cavities as shown. You should position the encoder boards over the encoder disks such that the disks fit in the center of the slot on the encoder sensor. Fasten the encoder board to the motor bearing blocks using the flat-head Phillips screws provided. When mounting the encoders to the HDPE blocks, be careful not to over-tighten.
PAGE 8
Step 9: Drive Wheel Assembly Parts The HDPE and Aluminum drive assemblies have the same shaped pieces. The aluminum version utilizes tapped holes in the rim sections to hold the pieces together, whereas the HDPE version relies on additional #4-40 acorn nuts. Only HDPE plastic version includes nuts Step 10: Inner Tube Begin by inflating the inner tubes with a bicycle pump. Add just enough air to make them round, but not under any pressure. Insert them into the tires as shown.
PAGE 9
Step 11: Rims Place the main rim over the valve stem, being sure to line up the stem notch as shown below. Push it down tight so that the rim is well seated into the rubber tire. Align valve stem with notch in main rim The aluminum wheel kit uses #4-40 x ½” long flat head bolts which screw directly into tapped holes on the aluminum Main Rim section. The HDPE wheel kit uses the #4-40 x 1” long screws and acorn nuts that fit into a recess on the plastic Main Rim section.
PAGE 10
Step 12: Inflate Tires Inflate the tires; 20–25 psi is optimum for traction, load capacity, and shock absorption. HIGHLY ADVISE using a bicycle hand pump to inflate the tires since the air capacity is so small, or a regulated air compressor set between 20 and 25 psi for safety and best results. DO NOT EXCEED 35 PSI as this may cause the tube to rupture and/or break the inner rim of the HDPE version of the kit.
PAGE 11
Step 14: Mounting to a Robot Platform If you are using your Motor Mount and Wheel Kit with the Arlo Robot Base Kit (#28960), follow the mounting instructions in that product’s documentation. Go to www.parallax.com and search “28960.” To mount this drive system to your robotic platform of choice, you can use the mounting holes shown below (wheels removed for clarity).
PAGE 12
36-position Quadrature Encoder Operation The 36-position Quadrature Encoders provide a convenient means to reliably track the position and speed of each wheel at all times. With the (included) Encoder disks, each Encoder assembly has a basic resolution of 36 positions per rotation. However, because there are two sensors in each assembly, this results in a potential resolution of 144 positions per full tire rotation. This translates to a linear resolution of approximately 0.
PAGE 13
Product Compatibility Notice The original Motor Mount and Wheel Kit (#27971) contained Position Controller Kits (#27906). The current version of the kit includes 36-position Quadrature Encoder Kits. The 36-position Quadrature Encoder Kit is NOT an electrical drop-in replacement for the Position Controller Kits. The communication protocols and electrical connections are substantially different. Microcontroller code written for one system would not be compatible for the other.