Featured throughout this catalog are motion and manipulation instruments which are
suitable for motorization. Motorization options for specific instruments are listed on
the page in which they appear. Specifications for each motor option are
identified with a single letter code ("A" through "F") listed as “Motor Spec” in the
options description table. Detailed specifications for each motor are listed in
this section and are arranged alphabetically by letter code.
MDC reversible AC motors are an economical motorization solution for
continuous motion applications. These motors are equipped with a load limiting
clutch rated for 50 oz-in of torque to prevent instrument overload conditions. Motors
come with three wire leads and a capacitor which must be wired by the customer to suit
application circuit requirements. Motor direction reversal is accomplished by wiring
reversal. Current applied to the blue and red leads produces a clockwise rotation while
applying current to the blue and black leads produces counterclockwise rotation.
MDC 90 volt direct current reversible motors are of the permanent magnet type featuring
high efficiency, no field supply requirement, low heat and linear speed-torque
characteristics. Two leads with integral connector provide easy mating with 90 volt
motor controller. These motors are furnished with an integral gear unit with 180:1 gear
reduction. The gearing is of the helical-spur design with helical gears in
the primary stage for quiet operation and hardened spur gears in the secondary stages. Mounting
dimensions conform to NEMA 2-11 standards.
Miniature DC motors are used on all MDC motorized miniature rotary and linear motion
instruments. The built in gear head with a 262:1 gear ratio gives this motor a
maximum torque load of 20 oz-in. Devices fitted with these miniature
motors are constructed with a load limiting clutch to prevent motor burnout. Motors are mounted
to motion instruments inside anodized aluminum housings with inline or side mount
drive geometries. Inline geometries can also be purchased with a 16 pulse per revolution
Stepper motors are devices which position loads by operating in discrete increments or
steps. The stepping action is accomplished by switching the power to the motor
windings so that the motor phases are energized in a specific sequence.
Stepper motors are capable of very precise positioning without the use of complicated
and expensive feedback devices. MDC uses SLO-SYN® DC stepper motors on
all motion and manipulation instruments fitted with stepper motors. These are
brushless, permanent magnet motors that have full-step increments of 1.8°. They can
also be made to operate in increments of 0.9° to 0.014° when half stepping or
microstepping techniques are employed. SLO-SYN® motors have permanent magnet
rotors and eight-pole stators. They do not have brushes, ratchets or detents to
wear out and they use shielded, lubricated-for-life ball bearings to insure maximum
reliability and long life. Tests indicate a typical minimum life of five years. These
stepper motors operate on phase-switched DC power. The motor shaft advances in
steps of 1.8° (200 steps per revolution) when a four step (full-step mode) input
sequence is used and in steps of 0.9° (400 steps per revolution) when an eight-step
(half-step mode) input sequence is used.
Microstepping is a method of stepper motor control that allows the rotor to be positioned
at places other than the 1.8° and 0.9° positions provided by the full-step and halfstep
methods. Microstepping occurs between these two angular points in the
rotation of the rotor. These stepper motors are suitable for 1/10 and 1/125 microstep
increments. A benefit of microstepping is that it reduces the amplitude of the
resonance which occurs when the motor is operated at its natural frequency or
subharmonics of that frequency.
In-vacuum stepper motors are ideally suited for the precision movement of delicate
specimens such as silicon wafers in ultrahigh vacuum. The use of in-vacuum
stepper motors results in considerable savings in mechanical complexity with
resultant gains such as cost reduction, improved reliability and decreased backlash.
In some cases the use of in-vacuum motors can mean the complete elimination of edge
welded bellows. The particulate generation of these stepper motors is
minimized by the total absence of metal to metal sliding surfaces. This and their low outgassing
characteristics make these motors especially suitable for sensitive semiconductor
handling applications. Other applications for which these motors have been employed include
precision in-vacuum UHV manipulators, monochromator mechanisms for synchrotrons, ion beam lithography and
sample transport in UHV.
All motor controls are sold separately and are not included in the motorization option
Alternating current (AC) motors do not require motor controls since they are
designed to be wired directly into an alternating current wall circuit.
DCM-SC-90 controllers are designed for use with 90 VDC motorized instruments. This
controller provides bidirectional motor control in continuous and jog
modes. Motor speed is adjustable from 0 to 10 rpm via voltage regulation. Feedback circuitry uses
the motor’s “Back-EMF” to provide a flat torque-speed curve. Additional
features include transient and surge protection, line voltage compensation, soft start, discrete
silicon-controlled rectifiers and diodes for higher amperage output and better heat
dissipation. Controller is wired for 115VAC input and is provided with a 2 conductor
cable for direct connection to MDC 90V motorized components.
DCM-SC-12 controllers are designed for use with 12 VDC motorized instruments in this
catalog. This controller provides bidirectional motor control in continuous and jog modes.
It provides motor speed adjustment from 0 to 20 rpm via voltage regulation. Feedback
circuitry uses the motor’s “Back-EMF” to provide a flat torque-speed curve. The
controller is wired for 115VAC input and is provided with a 2 conductor cable for direct
connection to MDC 12V motorized components via a standard 2.5-mm plug.
Rear panel voltage switch allows the DCMSC- 12 to accept 110 or 220 VAC line
To learn more about these options, email inquiries to firstname.lastname@example.org or contact MDC Technical Sales team by phone at 800-443-8817.