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Robot Base Kit (#28976 and #28977)
The Robot Base Kit is available in either White (#28976)
or Black (#28977) high-density polyethylene (HDPE).
Ideal for medium-sized autonomous robotics system
development, this sturdy platform can handle indoor
and outdoor environments.
This kit includes the Base plate, Acrylic Battery Shelf,
and a set of mounting hardware for attaching the
12 V Motor Mount and Wheel Kit (#27971), and two
Caster Wheel Kits (#28971); kits sold separately.
Features
Precision machined HDPE Base plate with
pre-drilled mounting holes
Laser cut ¼” thick Acrylic Battery Shelf
Mounting hardware 7/64” Hex Key included for
quick assembly
Designed and pre-drilled for use with the
12 V Motor Mount and Wheel Kit (#27971), and
two Caster Wheel Kits (#28971), sold separately
Pre-drilled for use with up to ten PING))) Ultrasonic Distance Sensors and Protector Stands;
Ping))) sensor (#28015) and Protector Stand (#725-28015) sold separately
HDPE Base plate is virtually indestructible, yet easily drilled, cut, or modified to suit your design
preferences and application needs
0.375” (0.95 cm) thick x 17.75" (45.09 cm) diameter HDPE Base plate
0.250” (0.64 cm) thick x 4.5” x 13.25” ( 11.43 x 33.66 cm) Acrylic Battery Shelf
Sturdy but not heavy; 3.15 lbs (1.43 kg)
Bill of Materials
Part #
765-28977
765-00002
710-00024
710-00025
712-00005
710-00032
710-00006
713-00001
725-00021
Quantity
1
1
4
4
8
6
6
6
1
Description
Robot Base Top – Black (or White #765-28976)
Transparent black ¼” Acrylic Battery Shelf
¼” x 20, ½” long stainless steel socket button head screws
1/4 x 20, 3/4” long stainless steel socket button head screws
¼” stainless steel washers
#6-32 x 3/8” stainless steel socket head cap screw
#4-40 x ½” Pan Head Screw
#4-40 x 5/8” Standoff
7/64” Ball End Hex “L” Key
Copyright © Parallax Inc.
Robot Base Kit (#28976, #28977)
v1.0 1/18/2011 Page 1 of 4
Additional Items Required
Safety glasses
Drive motors and casters. The 12 V Motor Mount and Wheel Kit (#27971) and two Caster Wheel
Kits (#28971) work well, and are used in the assembly instructions below.
Alternatively, you may provide your own drive system, in which case the HDPE Robot Base Milling
/ Modifying Tips on page 4 may be of help.
Assembly Instructions
Step 1: Attach the two 12 V Motor Mount and Wheel Kit Bearing blocks to the bottom of the Robot Base
using (4) ¼-20 x ¾” long stainless steel button head screws and washers.
(The “bottom” of the Robot Base is the side that has the two sets of (3) caster mount holes
showing. These are ‘blind’ holes, because they do not go all the way through the material. This
results in a cleaner look, and eliminates the need for washers and nuts on the top side of the
Base plate).
Step 2: Attach the Battery Shelf to the bottom of the bearing block using (4) ¼-20 x ½” long stainless
steel button heard screws and washers. Be sure that the Parallax logo is facing away from the
bottom of the Base.
Step 3: Attach the front and rear Caster Wheel kits to each of the two sets of blind holes, using (6)
6-32 x 3/8” socket head cap screws. There is no need for nuts or washers. Use the (included)
ball end hex wrench for this operation. Retain the hex wrench for future use—it works well if you
decide to install Ping))) Ultrasonic Distance Sensor Protector Stands around the perimeter of the
Base using the pre-drilled holes.
Step 4: Your battery should be well secured to the battery Shelf. Several methods can be used, including
zip-ties or double-sided sticky foam tape. If you’re using a standard 12 V, 7.5 Ah sealed lead
acid (SLA) Battery, then refer to Figure 1. The (included) 5/8” F/F standoffs and #4-40 x ½”
long pan head screws can hold your battery securely as shown. The staggered hole patterns
accommodate slight dimensional variances between different brands of batteries.
Step 5: The additional holes in the Battery Shelf can be used at your discretion, or as mounting locations
for additional computer/control boards, or future hardware enhancements. See Figure 2 and
Figure 3.
Copyright © Parallax Inc.
Robot Base Kit (#28976, #28977)
v1.0 1/18/2011 Page 2 of 4
Figure 1
Figure 2
Copyright © Parallax Inc.
Robot Base Kit (#28976, #28977)
v1.0 1/18/2011 Page 3 of 4
Figure 3
Step 6: You can drill additional mounting holes in the Battery Shelf as required. Begin by drilling a small
pilot hole, and then use ever-increasing bit sizes until the desired diameter is reached. Acrylic is
much more brittle than HDPE, so use caution when drilling or cutting the Shelf.
HDPE Robot Base Milling / Modifying Tips
HDPE is a non-brittle form of plastic. The White version (#28976) is FDA approved for direct
food contact (not that it matters unless you’re going to place raw food on your robot). Although
Black (#28977) is not FDA approved, it can be machined in the same manner as the White
version.
Most common woodworking tools can be used to drill, cut, carve, and tap (cut screw threads in)
HDPE. Jigsaws, circular saws, standard drill bits, routers and router bits, all provide various ways
to customize your Robot Base.
Although you can tap HDPE, in most cases this is not necessary. Simply drill a thru-hole that is
slightly under-sized compared to the screw itself. As you insert the screw into the hole and twist
it in, the screw will cut its own threads. Go slow so that you don’t strip out the threads.
You’ll notice that the HDPE will act as a lock-nut. That is, when you stop turning the screw, the
HDPE will tend to bind and hold the screw tight.
If you do over-tighten and strip out the threads, remove the screw. Then, using a small straight-
blade screwdriver and hammer, simply tap around the perimeter of the hole to “cave in” the
material a bit. Now re-insert the screw, and it will tighten right up as it cuts a new set of
threads.
Resources and Downloads
Check for the latest version of this document and additional resources on the Robot Base product page.
Go to www.parallax.com and search “28976”.
Copyright © Parallax Inc.
Robot Base Kit (#28976, #28977)
v1.0 1/18/2011 Page 4 of 4
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