MTD-3 Mechanical Testing Device

Available for passive and active marker systems, this is an inexpensive and vital tool for any lab that performs 3D and force measurements.

The new MDT-3 (Mechanical Testing Device) is a precision-machined tool that can be assembled in less than a minute to create a force plate test object suitable for a number of 3D biomechanics laboratory tests and supports the addition (optional) of a standard load cell at the lower end.  It allows the user to apply a pure force vector to a force plate within the Motion Capture environment, determine the alignment of the force plate within the calibrated 3D measurement space and optionally measure the applied force.

The MTD-3 is comprised of the following items supplied in a plastic storage case:

• Five wands
• Five retro-reflective markers (for passive systems).
• Five mounting disks (for active marker systems).
• Calibration testing rod with a 3/8-16 NC threaded conical tip and US 3/8-24 thread dummy load cell with matching lower conical tip.
• Test plate with dual bearing points.
• Handle with recessed bearing surface

Laboratory calibration tests are conducted in order to ensure the accuracy and reliability of kinematic and kinetic data which are essential to the appropriate application of movement analysis data and research purposes. Thorough laboratory calibration includes the accurate determination of the positions of the force platform(s) and cameras in the laboratory coordinate system, as well as correct setting of force platform parameters such as analog scale factors and origin offsets.

Any errors in the parameter settings or calibration measurements can lead to incorrect values of kinematic and/or kinetic variables calculated during a movement analysis.

The calibration test incorporates data derived from the force platform and data generated from the camera measurement system. The degree of spatial and temporal agreement between these two sets of data provides an assessment of the joint working status of the kinetic and kinematic systems.

A small number of variables are calculated and presented for inspection – these enable the user to detect the presence of errors from a large number of potential sources.

A simple test using the MTD-3 in any gait analysis lab can document relationship of any force plate within any 3D data collection volume. The device is simple to use - just assemble and use it to apply a force to the plate that you wish to test and then analyze the data using the CalTester software package available from C-Motion.

Load cell Support

The MTD-3 includes a dummy (non-functional) Load Cell that is dimensionally identical to a standard Futek LCM200 Load Cell. The standard MTD-3 does not include the Futex load cell or load cell amplifier but supports any load cells that use a standard US 3/8-24 thread at both ends.

The MTD-3 is designed so that the load cell attaches to the bottom of the rod and tip. The physical characteristics of the MTD-3 are identical to the original MTD-2 with virtually the same mass and identical dimensions. Although the MTD-3 is designed specifically for the Futek LCM200 Load Cell, any other load cell with similar dimension that uses a standard US 3/8-24 thread at both ends of the load cell should work.