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Download RevC Testhead Tilt Adjustment.pdf 7 pages (5 Mb)


Paper version included with hardware.

Product CatalogMVRPPV1A Test Head Lock (Rev C) Retrofit Kit - Upgrading the Rev A&B Infrastructures with Rev C Rotational Lock

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The Cassini 16 Test Head allows for tuned adjustment to the swivel joint assembly used to center the total 5° of front and back swivel based on the weight of the installed TIMs and Fixture. Without the adjustment, added weight on the Test head may cause it to lean forward, preventing the easy alignment of the Testhead with the Handler's docking mechanism.

Tilt Compensation Tuning

Tilt Compensation can be adjusted to set the center 0° neutral postilion for tilting the Test Head forward and back, optimizing the Test Head for additional loading. Tuning is intended to be performed by an authorized Roos Instruments agent. A pair of set screws are adjusted until the maximum tilt is desired. Since the adjustment needs to be made with the Testhead unloaded, a couple of angle measurements and simple calculations must be performed.

Please contact [email protected] to schedule an adjustment.

Tools Needed
#1 Philips Screwdriver
3/32 Allen Wrench (TODO: Confirm tool size)
"Measure" App on RiPad or Bubble Level

Infrastructure Model Required
RI8568C or later, or MVRPPV1A - Test Head Lock (Rev C) Retrofit Kit (specifically MV1FFZ5B Pivoting Head Arm retrofit)

Field Upgrade Procedure
This is intended to be performed by an authorized Roos Instruments service technician. The goal of this adjustment is to raise or lower the Test Head until the center forward and back tilt is near 0 degrees. The head should stop tilting at +/-2 degrees when pressed forward and back to allow for automatic alignment while docking. Instead of balancing the Testhead to neutral 0 degrees, we will be tilting it forward to the maximum position, thus creating a reliable set point to make our angle measurements.

NOTE: This procedure can be performed after the new rotational lock and arm are installed but immediately before re-installing the side panels, see Service Bulletin - RI8568C Cassini 16 Rotational Lock Assembly Upgrade (https://roos.com/docs/RBEH-AZPTND)
  1. With a fully loaded Test Head (including all TIMs, Fixture and additional docking hardware), use the Measure app on the RiPad (Bubble Level) to measure the tilt angle with the head fully tilted forward and document as 'X'. Pull the front of the Test Head down with your hand and measure
    Loaded Max Angle X = _____ (target after alignment should be -2°, fully loaded angle should be less than "-2",i.e. "-5")
  2. Remove all TIMs and Fixture, leaving any custom docking hardware that may be permanently attached to the Test Head.
  3. (If not already removed) Unscrew and remove the Test Head access panel, keep all parts for later re-installation.
    Diagram A
    shows the 16 screw locations needed to remove the access panels for either the Test Head, 3 on the back, 12 on the top, and 3 on the front.
  4. Rotate the Testhead so the Fixture side (top) is facing to Up (0 degrees). Lock the Testhead rotation.
  5. With the Testhead unloaded, pull the front of the Test Head down with your hand and measure the angle again. (should be approx. "-2")
    Unloaded Angle Y = _____
    (See pic of testhead pushed down in forward)
  6. Compute the Target Angle (Z) by subtracting the Unloaded Angle (Y) from the Loaded Angle (X).
    X - Y = Z _____
    For example, if Loaded Angle is measured as "-5°", and unloaded angle is measured as "-2°", then the result would be "-2" - "-5", or -2 + 5 = 3.
  7. Identify the two screws that need to be adjusted to set the angle range.
  8. Adjust the two set screws until the Unloaded Target Angle (Z) is reached when the Test Head is pressed down forward. Try to perform the same number of rotations on both screws.

    To raise the front of the Test Head, loosen the front screw first and then tighten the rear screw.

    To lower the front, loosen the rear screw first then tighten the front screw.

    Repeat the process until the Target Angle (Z) is reached.

    For example, we want the angle to measure +3°, so we have to adjust the arm angle from -2° to +3, a total of +5° of change. This requires raising the front. So loosen the front screw 5 times and tighten the rear screw 5 times. Repeat that 10 times and make an angle measurement.
  9. Test the adjustment by adding all TIMs and Fixture. Measure the Front/Neutral/Rear tilt angles and confirm they are approximately -2°/ 0° / +2°. If not, remove all the TIMs and Fixture repeat step 7.

Diagram A

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