QA_3D CT Scanner_7 January 2021.pdf

FA8126-21-R-0002 3D CT Scanner

Questions and Answers – 7 January 2021

No. Issue Description and/or Question/Recommendation Government Response

1 For the larger part/assemblies, does the User intend to scan the entirety of the part/assembly or only a portion of the part/assembly?

The User requires both as some applications will require the inspection of a whole assembly (e.g. turbine disk) or a portion of a part/assembly (e.g. HPT shaft). The anticipated workload is variable and comprises looking at aircraft structures and engine components as necessary. Please see related Q&A No. 9 and 17.

2 Is the delivery date a hard date, or is it flexible? The delivery date is the requirement. However, please propose what is realistic for company. The delivery date is not a factor to determine technical acceptability.

3 Regarding Scanning Capability 3.1.13.1: As flaw detection is ultimately dependent on sample geometry, what is the size and geometry of the 17-4PH CT Standard Samples?

The Government has chosen to remove this requirement from the SOW due to an inability to produce unique, Government manufactured phantom sample.

4 Regarding Scanning Capability 3.1.13.2: What is the material, size, and geometry of the referenced samples?

Also is the +/- 0.0001 inches referring to a length measurement precision value?

Please see Q&A No. 3.

5 Regarding Scanning Capability 3.2.3.1.4. Minimum focal distances: are these the desired maximum focal distances (source-to-detector)?

Per revised SOW 4.3.3.4 Focal Distance (Tube to DDA):

450KV – minimum 80 inches maximum spacing 225KV – minimum 80 inches maximum spacing

6 Regarding 3.9 Enclosure: 3.9.1 constrains the enclosure to a maximum footprint of 10’ deep by 15’ wide by 11.5’ tall. Will larger enclosures be considered, granted they still meet the perimeter spacing and area requirements in second part of 3.9.1? This would allow all offerors to effectively utilize the entire space with their available designs, while still meeting the perimeter and electrical enclosure stand-off requirements.

Yes, larger enclosures will be considered, but the maximum ceiling height is 15 feet. If exceeding 11.5 feet, please ensure that the added height does not interfere with the ability to assemble the enclosure. Additionally, the height of the system must be no higher than 18 inches from the maximum height of the room to allow for an operating fire suppression system.

7 Regarding 3.10.2.13 under Software: This statement is unclear, could you please clarify this requirement?

This was a typographical error. See revised SOW 4.4.1.9.2

8 Regarding 5.2 Vibration Dampening System: Have any vibration analyses been performed in this area previously? Are these reports available to offerors?

Analyses were performed two years ago that may not be representative of current building conditions. Analyses will be made available with the release of the solicitation amendment.

9 Regarding 3.2.3.1.1. System Motion: Are the vertical and horizontal travel limits based on the desired maximum part size of 60” x 60” (see 3.3 Chamber Size)? Will slightly shorter travel limits be acceptable if they still guarantee full radiographic imaging of the maximum part size listed in 3.3 Chamber Size?

Yes and yes. Please see SOW for revised references.

10 Regarding 3.7. Safe and Ergonomic Loading…(please see 10.a-10.c)

Please see below.

10.a What is the maximum weight and part size to be used with the loading system?

The User anticipates a weight of up to 400 pounds for some stacked engine rotor part assemblies, and the User expects to draw in a variety of part sizes and weights. There is no set workload or production item planned, but the User needs this capability based on parts historically received for other inspection purposes. See revised SOW 4.2.2.

10.b Is there a reason the loading system must be contained within the shielded enclosure?

It does not have to be within the enclosure as long as the lifting device can reach into the enclosure or have a retractable table to load parts outside of the enclosure and then slide into the system.

10.c Would an externally mounted loading system, capable of moving parts into the room be acceptable?

Yes, as long as it does not extend outside the perimeter of the allowed space.

11 Regarding 3.10.1.10-11. GPUs & 96 GB Video RAM: Is this tied to a specific software requirement, or to the reconstruction software performance of a specific offeror? Are offerors being evaluated on meeting the hardware specification, or on overall reconstruction and visualization performance? Will hardware not meeting this specific requirement be acceptable if comparable reconstruction performance is met on a reasonable scan volume? Multiple vendors have an acquisition and a reconstruction computer.

The SOW has been revised to state that two workstations are requested, one for acquisition and one for data reconstruction/processing. Although the User expects demanding computing power for the workstations, the Government asks that the computer specifications for each to meet the minimum operating requirements to operate efficiently and error-free by the OEM system and third party add-on software necessary to fully operate all aspects of the system at the same time. See revised SOW 4.4.2.

12 For requirements pertaining to the Time and motion analysis, are offerors being asked to include any load frames or other in-situ hardware accessories in their proposals? Are digital volume correlation (DVC) software packages desired as part of the time and motion analysis? These capabilities generally require a high level of customization, as additional interfacing may be required for the most effective implementation.

Is there a specific application in mind that has already been shared with any potential offerors?

No special hardware needed. Real time imaging to be provided by software of internal parts movement. Applications for this capability include heat exchanger assemblies and fuel nozzles that cannot be disassembled without cutting to find blockages.

13 Reference: The CT scanner shall be capable of conducting time and motion analysis utilizing X-ray computed tomography.

Question: What type of application is required for time and motion analysis with the CT system? Is there really a need for 4D CT?

The Government has determined that the time and motion analysis is acceptable but is not required. A system with this capability will not be rated higher than a technical proposal without time and motion analysis. However, the User requires a system that can scan 3D-printed metal parts with all moving parts built into an assembly. These parts should not require disassembly and would benefit from scanning to confirm proper internal functionality or identifying where potential defects/binding exist during actuation in support of protoypes and reverse engineered parts.

14 Reference: The CT Scanner shall utilize geometry tools to determine system geometry for reconstruction of CT scans.

Question: If the CT system did not require geometry tools but had automatic reconstruction would this meet the requirement? This would save additional reconstruction time.

Yes, it will meet the requirement.

15 Reference: The CT scanner will, at a minimum, be capable of accurately and precisely capturing 95% of flaws in USAF unique 3D printed 17-4PH steel CT Standard Samples.

Question: What are the size and the maximum material thickness of the 3D Metal printed samples?

Please see Q&A No. 3.

16 Reference: The CT scanner will, at a minimum, be capable of accurately and precisely measuring samples/revealing defects at a resolution of 0.001 inches +/- 0.0001 inches. Please see below questions 16.a-16.e.

Please see Q&A No. 3.

16.a Are the sample defects imbedded in the test samples a true .001”?

Please see Q&A No. 3.

16.b What method of accurately measuring is required for the sample?

Please see Q&A No. 3.

16.c What types of gauges should be used in the study? Please see Q&A No. 3.

16.d Will there be cut analysis with the CT scan data to confirm MPE (maximum permissible error) and Measurement system uncertainty?

Please see Q&A No. 3.

16.e Is this system being used for Metrology purposes and be temperature controlled?

Yes, and Metrology is one application. The facility will be at 68F +/- 2 degrees.

17 Reference: The CT Scanner must be able to accommodate a part size of up to and including 60x60”.

Question: Does the CT scanner have to CT scan an object of 60” x 60”, or just fit in a part of that size for imaging?

The CT Scanner should accommodate parts up to 60”X60”, but it is not required to scan the whole area. Please see Q&A No. 1.

18 Reference: Contractor shall be ISO 9001 certified.

Is there an equivalent certification that would be taken into consideration that DR/CT systems have been audited to of which is applicable more toward Aerospace and Defense? Ie. AS9100, or Nadcap?

Yes, equivalent certifications will meet the requirement. SOW has been revised.

19 Reference: T.O. 33B-1-1, 33B-1-2.

Question: Are these documents available for review?

Yes, these documents are publicly available and may be found at https://www.tinker.af.mil/Portals/106/Documents/Technical%2 0Orders/AFD-101516-33B-1-1.pdf

The Government has chosen to remove T.O. 33B-1-2 as it is not a current/active document.

20 Reference SOW section item #’s 3.2.3..2 & 3.4 - Tilt and Weight – What is the maximum weight requirement for the tilt stage? Is it also 400lbs

Yes, it needs to have the ability to tilt a part that is already on the stage.

21 Reference SOW Section item # 3.3 – Chamber size is specified as needing to physically accommodate a 60” x60” part. What are the respective DR and CT scanning envelope sizes? Is the RFQ intent to provide full CT scan coverage for an object that is 60” x 60”?

No, the intent is to be able to place a large part on the stage to inspect certain features. The User needs the CT Scanner to accommodate parts such as military jet engine disks and cases.

22 Reference SOW section item # 3.2.3.1.4.1 – Minimum focal distances for 450kV and 225kV sources. Are these minimum or maximum SDD specifications? Is there a range of SDD adjustment that is required?

See Question No. 5

23 Reference SOW section Item # 3.2.3.1.1 – Minimum of 65 inches of vertical and 36 Inches of horizontal travel.

What axis or axes is this specifying? Detector travel?

Object Travel? Is vertical and horizontal travel defined as +/- from center of detector?

Up to 60 inches vertical travel and up to 36 inches of X (front to back) direction of the part being inspected. See revised SOW 4.3.3

24 Reference SOW section item # 3.9.1 Can you clarify statement 2 stating “A minimum of 180” of overhead clearance will be required for assembly”? We believe there may be a typo or possible mis-wording … is this statement stating we must have at least 18” (not 180”) of clearance above the enclosure to allow for assembly?

This was a typographical error. The intent of the sentence was to note that there is only 180” (15 ft) of height clearance for installation and assembly of the enclosure. Please see corrected SOW and Q&A No. 6.

25 Reference SOW section item # 5.2 – Are there any further detailed specifications on the vibration levels to be expected in the “system installation” environment?

We can fully comply with a number of approaches but do not wish to over-specify and increase costs needlessly.

There is a considerable amount of vibrations with nearby passing cars, forklifts, and industrial equipment. There are vibration analyses test previously performed. Please see Q&A No. 8.

26 Regarding 4.3.3.1: Is the minimum travel distance specified in the requirement equal to the travel range of the source spot in the vertical direction, or simply the available rail length along which the source can move?

The optimal mounting position of a 450kV mini-focus tube limits the overall travel of the tube, even if the rail length meets the requirement.

This is the vertical travel available for the source and detector along its manipulator/rail system. Theoretically, no matter how you mount the source or detector, systems needs to provide a range of 60 inches of vertical travel.

27 Regarding Answer 6 and 4.2.1 (REVISED): The answer provided states that larger systems will be considered, however, the requirement still contains a maximum enclosure size. Could you please clarify specifically if

The SOW has been revised to clarify the maximum enclosure size. All sizes will be considered so long as the system fits within the 25’ X 12.5’ foot print to include all external system accessories and part loading mechanisms (if external). It should https://www.tinker.af.mil/Portals/106/Documents/Technical%20Orders/AFD-101516-33B-1-1.pdf https://www.tinker.af.mil/Portals/106/Documents/Technical%20Orders/AFD-101516-33B-1-1.pdf cabinets that exceed the maximum width of 15 feet specified in the requirement will be accepted, so long as they include the perimeter standoffs provided in the

SOW.

be noted there is a 15’ height max clearance for assembly purposes. Ancillary hardware outside of the enclosure would need to fit within the 312.5 square feet. Enclosure alone cannot occupy the whole 25’X12.5’ area.

28 Will the SOW be modified to reflect the agreeable responses to the room?

The SOW has been modified.