SPECIFICATIONS The basic MP1 package includes:
  • Steel main chassis: 24W x 3H x 6.16D, 14ga
  • Four pivoting outrigger struts with suspension springs for stabilizing wheels
  • Four stabilizing wheels, either 5 swiveling casters (MP1-2) or 8 fixed rubber tires (MP1-3)
  • Two 8 dia. rubber drive wheels
  • Two motor/gearcase assemblies
  • Two 12V/7AH rechargeable Sealed Lead-Acid (SLA) batteries
  • Dual channel motor controller with overload protection and two regulated 5VDC outputs for customer electronics
  • 6A Battery charger


OPTIONS (at extra cost)
  • Dampers (Hydraulic shock absorbers) Improves stability and reduces spring rebound bounce when operating on rough terrain or with heavy payloads. To order, specify option D.
  • Tandem Drive Wheels Improves traction and flotation on soft and loose surfaces. To order, specify option T.
  • Radio Control Provides speed (forward/reverse) and direction (right/left) control of the MP1. Includes 3-channel handheld transmitter, compatible receiver and antenna mounted on MP1. One transmitter/receiver trim channel is unused by the MP1 and is available. Also included is a small servo that may be driven by the third radio channel. Line of sight range is about 100 yards. To order, specify option R.



USAI plans to offer control, sensor, actuator and telemetry packages for the MP1 in the future. At present, however, you will have to roll your own. The speed controller that is included in the basic MP1 package has two inputs for controlling the speed and direction of each main drive wheel. The required control input is a Pulse-Width-Modulated signal that is compatible with common R/C signals: A 0-5V nominal (4.2-6V) pulse, 1-2mS in duration, repeated every 20mS. The pulse width specifies the speed and direction of the motor, with the shortest pulse giving maximum speed in one direction while the longest pulse will result in the maximum speed in the opposite direction. As the pulse width approaches about 1.5mS, the motor will slow and stop.

There is space inside the MP1 for mounting your own control electronics and up to 300mA (x 2) of regulated 5VDC for power, in addition to the 12VDC from the batteries.



The MP1 is designed to easily integrate additional electronic and mechanical components. The steel chassis can be drilled to mount additional components externally or internally. Holes for cable access to the center control section are provided. The battery holders raise the batteries about .125 from the surface of the chassis to allow cables to be safely run under them, from one end of the chassis to the other and to provide clearance for external fasteners

Bottom view, access plate removed, shows battery and motor/gearcase assembly  

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2002 United Service Associates, Inc.  16608 Arminta Street  Van Nuys, CA 91406

Phone 818-780-1886  FAX 818-780-1978 Email