Attachment 6 - Q and A - 4 March 22 - CO Signed.pdf

DEPARTMENT OF THE AIR FORCE

AIR FORCE LIFE CYCLE MANAGEMENT CENTER (AFMC)

WRIGHT-PATTERSON AIR FORCE BASE OHIO

4 March 2022

FROM: AFLCMC/PZIBC

1940 Allbrook Drive, Room 109

Wright-Patterson AFB, OH 45433

SUBJECT: Response to Inquiries regarding FA8601-22-R-0018

QUESTIONS

QUESTION 1: Would a cuboid made of stainless steel be a suitable sample print to send in for your team?

ANSWER 1: The cuboid would provide information about the capability of the machine, but is not required.

QUESTION 2: One of the requirements states the following: "Powder recoater assembly allowing the utilization of hard and/or soft wiper blades. Assembly shall allow between 1 and 3 blades to be utilized at once." Our standard setup is we supply 15 silicone blades (Shore 30).

We would like to understand if you'd expect us to supply you with the blades of different rigidity (for example, ranging from Shore 10 to 30) or if you plan to prepare these using your own means (for example, by using molding).

If you'd expect us to supply these, could you please indicate how many blades and what rigidity shall they have (for example, 5 blades Shore 10, 5 blades Shore 20, 5 blades Shore 30)?

ANSWER 2: We would prefer that wiper materials could be readily purchased as consumable items from the manufacturer or a 3rd party after the initial machine purchase. The requirement for utilizing multiple wiper blades refers to the desire to use up to 3 wiper blades in the wiper assembly at one time to give each part multiple wipes.

QUESTION 3: The additive manufacturing system is supplied with our proprietary slicer that makes full use of the machine's firmware and hardware. If your team expects to also use other slicers such as Netfabb or Materialize Magics, we can add them to the quote. If that is a requirement, please advise which third-party slicer is preferred by your team.

ANSWER 3: A proprietary slicer is acceptable.

QUESTION 4: The manufacturers of the thermal tomography camera recommend installing the camera outside of the build chamber, so that electronics won't be affected by the high temperatures inside the chamber.

Would that be acceptable for your team?

ANSWER 4: It is assumed that the thermography camera would reside outside of the chamber and view the build area through an IR-spectrum window.

QUESTION 5: In addition to this, they would like to better understand, what should be the maximum frame rate of the camera. If there is no clear answer, perhaps, it is worth discussing at what velocity you're planning to run the laser. Our standard solution assumes the laser is moving at a speed of up to 1m/s. (It is theoretically possible to set the speed at 30+ m/s, but it's only practically viable to test speeds of up to 3m/s, if you are planning to explore the upper limits).

ANSWER 5: No specific answer for frame rate, laser speeds utilized in our past and current work fall under 1m/s.

QUESTION 6: The slicer we developed is cloud-based. To connect to it, one needs the following:

• Stable Wi-Fi connection

• A modern version of the Google Chrome browser with Web_GL support

• Computer mouse

• Keyboard

The slicer can work with other browsers, but we believe Google Chrome provides the best experience.

The slicer can also be launched from mobile devices (with limited functionality).

I know that some government institutions have certain security restrictions over data processing and their

Wi-Fi network.

I would like to clarify the following:

– When uploading an STL file for slicing, the file will be sent to an external server to slice the model with the parameters set by you, then be returned back to your browser for download. Would this be acceptable for your team? Are there any restrictions (for example, only US-based servers can be used or your institution requires us to set up a local server at your facility (not the most budget solution))? Please advise.

– Once the sliced file has been downloaded to your PC, it can be passed over to the Machine Control

Computer via a USB drive, Ethernet or the local Wi-Fi network. If your security policies do not allow one of these connection methods, please advise, for example, we can disconnect the Wi-Fi module.

– As mentioned earlier, our solution assumes that you will be using two different computers, a Machine control computer to control the printing process of the 3D printer and a separate computer to prepare computer-aided design (CAD) models for printing. The machine control computer is supplied with the 3D printer. The cloud-based slicer to prepare computer-aided design (CAD) models for printing can be operated from any PC. Would you like us to supply you with a separate PC for that task, too, or do you plan to use your current PCs. If you'd like us to supply you with a separate PC for that task, please advise if there is a model of preference.

ANSWER 6: The use of separate computers is fine, but security requirements surrounding the files being processed sometimes excludes any data handling outside of government controlled networks. FOUO, CUI etc.

QUESTION 7: The requirements state: "The software shall allow conditional programming to modify laser processing parameters for each 3D printed part based upon user defined conditions without user interruption of the build."

Could you please give an example of a conditional programming task your team plans to set up? If we know the details, we will try to show, how the planned task will be executed in the software.

ANSWER 7: Simple case: If build height > 25 mm

Then increase the laser power on all components by 50 W

Our current machine would require a user to stop the build and change the laser parameters. We could also cut the part into 2 pieces and assign 2 different laser parameters.

Neither solution is ideal for this simple case.

A more useful case:

We have used an IR camera to log the steady temperature of a part after the laser exposures.

We suppose that it can be used as an indication that the time between melting passes is too short, or if the energy density is too high.

So we envision a system that could do the following:

If the thermography camera detects average temperature of the component rises above some set temperature. Then modify the laser parameters to decrease the energy density supplied to the part OR introduce a time delay to allow parts to cool further

Zachary Huffman

Contracting Officer