Dimensional Measurement Systems

Dimensional Measurement Systems

  There are 3 primary applications for the GapGun Pro when used for automotive exteriors; End of Line Audit, In-Line 100% Measurement and Random Audit.

  The operator has a choice of using two standoffs, one standoff (either upper or lower), or no standoffs with no loss of accuracy.  Inserting a standoff into a soft plastic gap or into the gap of a glove box can change the gap and flush of the surface you are measuring.  The GapGun head can be rotated in order to reach features which are difficult to see.  It also has advanced capabilities for hard-to-read surfaces and unusual shapes.

Automotive Exteriors

  End of Line Audit is typically used to check a large number of features on a car (50 to 200) once or twice a day.  A program is developed putting in the correct location where the feature is to be measured as well and as the nominal and tolerances.  A picture of the vehicle is displayed to the operator with an X indicating to the operator exactly where the feature is to be measured.  The operator continues to move from feature to feature, then from one area of the car to the next area, automatically recording both gap and flush measurement at a rate of approximately 6 to 7 per minute. The results are displayed in Red or Green on the color PDA on the GapGun Pro and are also displayed on the Presentation Package in green (in tolerance) or red (out of tolerance).  The result from the last several vehicles is displayed along with an SPC chart.  The results are also automatically downloaded to your SPC package.  This same method is used to check part(s) before installation while still in the fixtures.

  In-line 100% Measurement. The GapGun Pro is well suited to be used in-line for automotive checks.  The most common setup for this application is two GapGun Pro systems  running simultaneously from the same computer and providing results directly to the Check plan and an SPC package.  Usually these measurements are taken with the body in white or while still uncoated.  A one minute cycle time provides up to 16 points per vehicle using two GapGun Pro systems.  Among the many advantages of this setup is the ability of the GapGun Pro to be configured in such a way as to know what type of vehicle is coming up next on the line and to change to that program with no loss of time.  The GapGun Pro system also allows you to easily change the program for a particular vehicle if you want to change the area you are concentrating on.

Automotive Interiors

  With complex plastic components, imitation leather, high polished or reflective components assembled with extremely tight tolerances, the automotive interior is one of the more challenging applications for traditional gap and flush measurement.  GapGun Pro has several characteristics that make it idea for this application. 

  The versatility of the GapGun Pro is ideally suited to short-run evaluation.  An example is to measure three glove box locations for 30 cars in-line in order to view individual gaps and determine that none of those gaps vary more than .5 mm for the left to the right.  This can be easily done on our base check plan, which will not only record the reading but will also calculate the maximum change in the gap size from side to side.

 GapGun Pro automotive Excel Measurement check plan


  The GapGun Pro is used throughout the aerospace industry.  Some applications are the panel to panel assembly, wing components, engine cowling, passenger door(s), and the landing gear door.  Customers have seen dramatic improvement in productivity and accuracy, with the added advantage of having permanent records.

  The GapGun Pro system offers several advantages. It has the ability to measure complex geometric shapes. Measuring on surfaces from carbon fiber to a reflective surface of aluminum is routinely accomplished.  Frequently the programs are called on to do additional calculations on a set of features such as a door tolerance of .080” bandwidth where no individual side can see more than a .040” deviation between the points. 

Feature Measurement on Precision Parts

  The GapGun Pro is also available in an ultra-high accuracy version, the FOV7/BSE.  The FOV7/BSE has a field of view of 7mm. It is not normally used for gap and flush measurement due to its small field of view.  The GapGun Pro BSE is designed to measure small features and forms.  Some examples of these features are on-edge chamfer, small radii or burrs.  It can also measure scratches both in depth and width.  This GapGun Pro BSE is specially designed to handle highly reflective and shiny surfaces as well as carbon fiber.  The resolution on this system is .0005”.

  Third Dimension's GapGun Pro is a handheld device which projects a laser line projected perpendicular to the gap onto a feature visible by a high resolution CCD camera.  Measurement is initialed when the operator brings the GapGun Pro closer to the surface until it is within operating range (approx. 2 inches from the surface) indicated by green LEDs or when the standoff is used, contacts the surface.  It can be completely non-contact or with removable standoffs to center the device.  When the correct position is reached, the system will automatically collect images of the laser line using an embedded digital camera.  During this process, the line is digitized, the desired calculations are made, the nonconforming images are discarded, and the remaining images are used to calculate the gap, flush or form measurements.

 GapGun Pro V-change allows for versatle measurement head swap

 GapGun MX non-contact gap and flush on car door profile measurement

Gap and Flush Measurement Automotive and Aerospace Applications