Payload considerations, Adjustments – Nor-Cal Precision Manipulators Version 1.5 User Manual

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Information in this manual is subject to change without notice.


The EMT Series instruments have a 20# equipment payload for standard vertical (NOT inverted) operation. This payload is based upon the total equipment load
on the traveling flange with the base flange securely attached to the customers chamber, providing a strong and stable mounting. The payload center of gravity
must be within the diameter of the traveling flange OD (Normally 2.75”) and within 8” of the flange face.

Special models are available for special mounting and payload requirements. If you unit is such a special one, verify the unit you have is correct for the applica-
tion. If not, consult the factory if your application requires:
Payload greater than 20#
Center of gravity beyond above limits
Mounting orientation other than standard vertical
(angled, horizontal, inverted, etc.)


Your EM manipulator is correctly adjusted prior to shipment. This section is included to aid the user in making changes in these settings if he so desires.

LINEAR BEARINGS: The linear bearings are not adjustable on the EM manipulators.

TRAVEL LIMIT STOP COLLARS: Some models come equipped with stop collars clamped to the guide rods or the Z axis lead screw. These stops limit

travel to the specifications of the device, such that the bellows is not extended beyond its operating parameters. If a need arises to move these stops,

measure their locations prior to their removal, and replace them accurately upon re-assembly. Over extension of the bellows will cause premature failure of

the bellows and/or mechanical damage to the manipulator or other equipment.

MICROMETERS: Micrometer play is affected by two micrometer adjustments.

1. Micrometer thread engagement is adjustable by removing the micrometer handle and tightening or loosening a knurled nut on the barrel. This

normally does not need to be adjusted in the field.

2. The micrometer to stage coupling is adjustable via the approx. 1” diameter knurled cylinder around the end of the micrometer spindle.

At the end of the micrometer spindle, under the 1” dia knurled cylinder, is a small, chrome plated, dome anvil. This must be finger tight to

properly load onto the cross shaft. These are properly adjusted at the factory, and should not require further adjustment.

When re-installing the micrometer/ micrometer block assemblies, the following procedure will assure the best alignment.

1. Install and snug the two 1/4-20 SHCS. Back each screw off 1/8 to 1/4 turn.

2. Assemble knurled collar/bearing at end of micrometer spindle into receiver on guide rod. Tighten firmly finger tight. This will align the

micrometer assembly.

3. Tighten the two 1/4-20 SHCS. Back off the knurled adjustment collar to a light tension, without axial play. Test operation for smoothness.

Z DRIVE: The two main bearings in the gearbox assembly are pre-loaded at assembly via the main drive gear. This is locked into place by the main

setscrew in shear. Shimming should be used if adjustment is ever required. The spiral drive gear set is adjusted by positioning of the upper gearbox housing

before locking down the two 1/4-20 SHCS mounting bolts. A slight force toward engagement is usually best to minimize gear cogging. If smooth Z drive

cranking is not obtained under load, this placement should be repeated. This alignment should not be disturbed unless necessary.

BELLOWS ASSEMBLY REMOVAL: The bellows assembly is held by its flanges in the traveling and base stages. The base is held by socket button head

bolts. Four socket head cap screws (SHCS) installed at 45 degrees to the X & Y axis hold the top flange. The manipulator should be placed on a clear work

surface, and the Z drive adjusted to approximately one half travel. With a bellows protector wrapping in position about the bellows, the base bolts can be

removed, leaving one installed loosely for control. The SHCSs should then be un-threaded from the flange. The X & Y Stages may need to be moved to gain

access to the pins. The bellows/flange assembly then can slide along the Z axis, out of the driving stages.

RE-ASSEMBLY: One must be careful not to over flex the bellows during re-assembly. This is especially true of the longer stroke units. When re-fitting the

top flange to the X-Y stage, the SHCSs should be securely tightened into place. One must position the 2.75” OD flange both in orientation and axial position