Laser Scanning

Corinthian Data Capture is the laser scan metrology division of Corinthian. Its purpose is to provide accurate and timely documentation of existing conditions; whether it is an entire building, its façade, a construction site or an architectural artifact. To this end Corinthian Data Capture owns and employs multiple types of laser scan metrology devices each deigned and used for a specific purpose.

The end result is faster and accurate measurements that can be converted into 2d drawings in any file format or 3D models that can be used for an architect’s approval, an owner’s visualization tool or be directly exported to one of our cnc machines for reproduction of architectural artifacts from simple moldings to elaborate carvings.

Generally, Corinthian Cast Stone or other companies (i.e. terracotta manufacturers, fiberglass manufacturers or natural stone companies) are called in to replicate existing architectural ornamentation on building that is often 75 or 100 years old. There are no prints available and if there is documentation there certainly are not any AutoCAD or 3d files from which to work. Thus the normal course of action to replicate one of these pieces of history would be to:

• Document the artifact. – This step is critical, since most restoration practices have the inherit possibility of damaging the stone or terracotta unit; it is everybody’s best interest to extensively document any unit to be replicated. In order to properly do so the following steps would be done:
  • Scaffold the site or area where the documentation is to occur.
  • Photograph the unit, using simple 2d digital cameras to record the shape, color and condition of the unit and surrounding area.
  • Measures the unit, measurements are usually done with a tape measure, straight edge and a sketch pad. If you get lucky the field technician might have a profile maker or a pair of calipers. While this methodology will suffice for Architectural drawings, the level of detail is not nearly enough to replicate parts from.
• Make a mold of the unit. – This can be achieved in one of two ways:
  • Make a field mold. – Making a field mold requires a tremendous amount of coordination between trades and weather,
    • Scaffolding: both suspended scaffolding and pipe scaffolding have their own set of safety concerns and OSHA guidelines to be followed for safe use by the mechanics as well as passersby. The mold makers (usually a team of two or three) must have the proper OSHA certifications to be on either type of scaffold.
    • Site protection: Since most materials used in the field are petroleum based, protection of the adjacent areas is crucial. The surrounding areas as well as the plant material and ground below should be covered with plastic to prevent harmful chemicals from damaging the adjacent areas.
    • Weather & time: all field mold chemicals will need heat and time to complete the curing process. Ambient heat is not only necessary but the building wall must also be warm- thus the need to encapsulate the area to achieve a wall warmth of 45 degrees F for the period of the field mold – 1 day before and 3 days during, must be considered. Additionally this must be considered for each area where field molds are required.
    • Sclupting: from the field mold a plaster casting is made. The quality of the part now is only as good as the field mold, generally 85% or so. The next step is to spend time from days to weeks re-carving and sculpting the part to bring it back to the original state as expected by the architect and owner.
    • Production Mold: the re-sculpted carving is now ready to be cast as a production mold with a mother mold back up. This process will take up to a week dependent upon the number of split-lines the mold has and the material the mold is made from.
  • Remove the unit from the building – The process of making a mold from a piece of masonry removed from the site is similar to making a mold in the field. This course of action may seem to save time and money but subjects the project to a different set of issues.
    • Removal: the first step is to “surgically remove the stone from the masonry wall” the intent is to ship the architectural artifact to the manufacturer in as good of condition and in as few pieces as possible.
    • Sculpting: “all the kings’ horses and all the kings’ men couldn’t put Humpty Dumpty back together again” yet that’s exactly the task beholden to the pattern and mold maker. While the masons in the field will do their best to minimize the damage and number of pieces a artifact may be in when brought for replication, invariably there is much time lost in restoring the artifact to its original glory.
    • Production Mold: the re-sculpted carving is now ready to be cast as a production mold with a mother mold back up. This process will take up to a week dependent upon the number of split-lines the mold has and the material the mold is made from.
    • Issues that arise when removing the artifact from the masonry wall:
      • Damage to the artifact. Simply put it is a difficult task to remove a unit embedded in the masonry veneer. Commonly the surrounding area is disturbed and the artifact is damaged. The removal leaves a void in the building envelope which must be addressed.
      • Temporary shoring & water proofing. Both of these activities cost a fair amount of money and have variable results, dependent upon the mechanic actually performing these duties. The result of poor workmanship is best noted at 3am when the building manager calls the restoration company and the architect to report water damage.

A unique laser scan metrology based approach to the recreation of our architectural history, borne from the absolute necessity for exact replication with minimal penetration to the building envelope and NO damage to the architectural artifact.

As a matter of fact the only penetration required is that of a probe for depth of the artifact being replicated. So how does Corinthian Data Capture do it? And what make us uniquely qualified to be your and other manufacturers’ choice “go to guy”? Our laser scan metrology division started out as a way for Corinthian Cast Stone to accurately and quickly field measure projects without the need for ever going back to a site for a missed dimension. Once we coupled the information gathered with our CNC departments’ capabilities, we had a winning solution. We scan, we draw, we cut, we cast, we deliver- right the first time. Corinthian Data Capture is here to provide you with solutions whether we are the cast / natural stone fabricators or not.

Our project management format is simple and outlined below:

Objectives

1. Maintain historic and architectural intent of the units to be replicated
2. Provide existing conditions documentation and archiving with high precision Laser Scanning Metrology
3. (if required) Replace existing elements with new artifacts that replicate with exactitude the original units.

Existing conditions documentation:

1. Deliverables:
   1. 3 dimensional model of the building, site or each unique element as required.
   2. Archive file for the use of the Owner and Contractors
   3. 2 Dimensional set of existing conditions drawings
2. Execution of the Existing Conditions Documentation:
   1. Prior to the removal of existing stones from the site, we document the existing conditions to achieve the stated deliverables by way of the following means:
      1. Documentation shall include laser scans, digital color photos, drawings, profiles, and location of stones used for impressions to replicate existing elements.
      2. Laser Scanning – existing conditions documentation using two types of laser scanners. In order to protect and preserve our history, objects or buildings of interest are scanned with the either the field scanner or hand scanner, this is non contact, line of sight technology. The information collected is used in conference presentations as supporting evidence of the subject presented by specialists and historians as well as reverse engineering applications.
      3. The Field Scanner:
         1. Fast and Accurate (within 1/25th of an inch) field measuring / recording of existing conditions in dense 3D point cloud models,
         2. The entire project digitally captured, which will be used to develop highly detailed and accurate plans, elevations and sections in CAD format.
         3. Corinthian Cast Stone owns the first Photon Laser Scanner in the world with an accuracy of +_ 2mm over a 240ft radius measuring distance while capturing a 360 degree 3 dimensional model
         4. Fast and Accurate inspection tool for analyzing and reporting geometric dimensioning and tolerancing (GD&T)
         5. Facilitates: Surface reconstruction, class A surfacing, 3D modeling
         6. Corinthian Cast Stone owns the first self-positioning and only truly portable handheld laser scanners. This technology combined with the latest 3 dimensional software will be utilized to create the 3 dimensional surface texture matching the original, weathered stone with face intact and have a variety of tooling’s (as selected by the Restoration Engineer) to replicate the existing finish.
      4. Capture a 3 dimensional model of each unit and assembly
         1. Mobilization – a means of access will be placed on site and the Restoration Engineer will be requested to spend time at the site with the Laser Scanning crew to mark each stone to be replicated. All units will be scanned to within ½ millimeter, ensuring that every detail is captured and can be re-created.
         2. Create a 3 dimensional model of each assembly as required.
         3. Create an archive file including the 3 dimensional model for the use of the Owner. This file will be available to all contractors working on the project on our FTP site (think BIM), allowing them access to the most accurate existing conditions documents available.

Laser Scanning? How do 3D scanners work?

• Laser Scanning Metrology (LSM) will be used to gather all necessary measurements. LSM involves using high-speed computer-aided laser scanners to generate high-accuracy measurements that are automatically plotted onto point clouds for 2-D and 3-D modeling, visualization or reverse engineering.
• Scanning at a rate of 120,000 points-per-second, CCS’s Laser Scanner builds a 360 degree point cloud of a scanned surface by sending an infrared beam into the center of a rotating mirror. Using encoders to measure the vertical mirror and horizontal axis of the Laser Scanner, the X,Y,Z coordinates of each point can be registered and modeled.
• 3D laser scanners send trillions of light photons toward an object and only receive a small percentage of those photons back via the optics that they use. With that technique, 3D scanners can build a 3D modeling object very quickly. 3D scanners produce a picture describing the distance information of each point to an object. Moreover, the 3D scanner photon’s probes the object surface at the speed of light.

Laser scan metrology services

• The documentation of entire facades
• The documentation of entire sites
• The documentation of architectural artifacts for replication

So does it work?

Corinthian has used this technology on over 100 projects to date. These projects ranged from replication of a single stone to a wonderful stories at George Washington HS, Washington Heights NYC. Or a MTA Maintenance Facility in Queens NY (click here for a case study).The simple fact is with the onset of BIM (building information modeling) it is critical to have the information ascertained by Corithian Data Capture.

Services are available for procurement with either a fixed fee structure or an hourly rate.

Corinthian Digital Capture’s effective capabilities are based in our strong synergy of certified technicians, hardware and software. This allows us to provide you a deliverable of data in a form suitable for your specific needs.

Our long range scanners have numerous applications:

• 3D Measurable as-built Information
• BIM and Facility Maintenance Archives
• Hazardous areas and equipment rooms
• Historical archive and Building restoration
• Roadway or bridge analysis
• Structural analysis
• Forensic scene documentation
• Accident scene reconstructions
• Virtual Tours or animations
• World Heritage and Archeology sites

Our hand held scanners have numerous applications:

• Architectural Artifacts documentation
• Ornamental cornices and building details documentation
• Interior plasterwork imaging in lieu of direct molds
• Non-invasive data collection of art objects and artifacts
• Reverse engineering of small parts and objects
• Replication of museum artifacts

Architects, Conservators, Contractors and Tradesmen realize many benefits through the use of laser scan documentation, including:

• Accurate as-built drawings for shop drawings, clash detection and contract closeout.
• Ability of remote examination of the site and close-up viewing of details and objects, minimizing field visits.
• Capture data for recreating ornamental details. Digital information is easily transformed into CNC machine code for mold or positive reproduction. Additionally these files are available in 10, 20 or 50 years from now to produce parts or information as needed for future restoration work.
• Dimensions can be extracted for use in creating shop drawings for fabrication of components, such as fiberglass cornice, windows, flashings, metal panel and masonry veneer. This allows the submittal process to start prior or independent of scaffolding or rigging.

Does Accuracy of Documents Effect Cost?

There is an adage ‘Garbage in – garbage out”. Perhaps this was never truer than in the construction world. Often Restoration projects are severely lacking in accurate construction documents and construction as built drawings from various trades. The result is a very costly project just to create the existing conditions drawings that will serve as the foundation for the new construction often without the need for elaborate scaffolding, decreasing project cost.

Laser Scan information captures everything with in the line of sight. This allows simple and easy creation of existing conditions plans, elevations and sections which in turn allows for:

• easy trade coordination,
• construction clash identification and mitigation
• inclusion into the project BIM program
• Considerably lower cost when compared to conventional surveying in measuring buildings to obtain dimensional information adequate for creating architectural drawings. Additionally, on historic facades conventional surveying will almost always allow for only diagrammatic elevation production because there are no means for capturing ornamental details.
  • Conventional surveying does not provide three-dimensional data for use in producing wall sections, parapets or other building component profiles. On projects where both scanning and conventional survey proposals were obtained, we consistently found that the cost of conventional surveying will almost cover both the cost of scanning and the CAD work necessary to create the architectural elevations.