Engine Bay Platform Questions.docx

The questions below came in. Please see the answers in red.

The drawing provided in the data package calls out a tolerance of +/- 0.010” for essentially every dimension in the drawing, including the raw dimensional lumber/plywood. By nature of the stock sizes on the shelf, the 0.500” Plywood would already fall outside of that allowable tolerance.

The question is, will a waiver or variance be granted for stock size material thickness etc?

It is possible that a waiver could be granted on a case by material case basis, however the dimensional tolerances are as is. +/-.010”.

Questions:

1. Non-Wood Materials Fabrication and Sourcing:

o Are the non-wood materials specified in the drawings, such as the rubber wrap and steel brackets, expected to be fabricated by the contractor, or are there NSNs for these items that we should source from? If NSNs are available, could you please provide them?

-The contractor is not required to fabricate the rubber wrap. COTS rubber edge trim is acceptable. Edge trim can be purchase through Mcmaster-Carr. Note: it is acceptable to wrap the edges in the specified areas with a non-slip rubber matting and fastened with staples on the reverse side.

-The steel brackets (made from mild steel) are to be fabricated by contractor.

-NSN parts are not required, and most non-wood material may be purchased from suppliers like: Mcmaster-Carr, Grainger, MSC, Industrial Supply, etc.

2. Rubber Wrap Plastic Specifications:

o The documents mention wrapping edges in rubber and covering faces with a rubber coating. Could you please provide more details on the type and thickness of the rubber required?

- SBR or neoprene traction mats, ribbed, textured, non-slip surfaces, approximately ¼” thick. Rubber edge trim is acceptable.

o If the plastic parts are to be fabricated can we 3d print them out of Carbon Fiber Reinforced Nylon filament instead of plastic?: This combines the strength enhancement of carbon fiber additives with the toughness and durability of nylon, making it generally the strongest 3D printing material.

-Impact resistant plastics, Acetal, UHDPE, Polycarbonate or ABS material are preferred. It is not necessary to 3D print or fabricate these parts.

3. Previous Round of Questions:

o Could you provide the answers to the questions submitted by other vendors before the solicitation date was extended? This information would help us avoid duplicating questions and ensure we address all relevant aspects of the solicitation.

See below.

4. Construction History and Warranty Responsibility:

o Have these platforms been constructed before? If not, why is the Navy Airforce holding the contractor responsible for warranting the design? We are willing to warranty the craftsmanship and materials but not the design if it is new. If these platforms were previously fabricated, could you provide information on their longevity and performance?

This statement appears to be from a template document. In essence, this statement attempts to hold the contractor responsible for producing a product that will function safely and reliably. The contractor, using best industry practices and the drawing parameters, should have confidence in their ability to fabricate platforms capable of supporting the weight of people. Examples of these platforms have been in use safely for over 8 years and have required little maintenance or repair.

5. Warranty Term:

o What is the term of warranty the Navy is looking for with respect to materials and defects? Will they be put to use right away?

The warranty terms are as specified in the SOW. Yes, the platform will be released to production after acceptance inspection and approval.

6. Environmental Exposure:

o Are these platforms expected to be subjected to moisture, such as oil and other substances, during use for repairs? This information will help us select the most appropriate materials and finishes.

The platforms may be staged outdoors and exposed to acclimate weather on a limited basis. They will be exposed to occasional light hydraulic oil spills.

7. Tee Nuts Installation:

o Are tee nuts expected to be counterbored? There is no callout for this in the drawings, so I would assume not, but confirmation would be appreciated.

Counter bore or drill through is acceptable. Tee nuts may be purchased through a supplier such as Mc Master-Carr. The size is determined by the contractor’s selection of hinge and the material thickness of wooden and/or rubber stack-up thickness. Example part number: 90975A027 Steel Tee Nut Insert. The hinges maybe purchased through a suppler such as Mcmaster-Carr as well.

8. CF Callout:

o What is the meaning of the "CF" callout on several dimensions (e.g., on -17)? Is it related to a specific manufacturing or inspection process?Continuous Feature (CF) meaning the alignment or smooth transition across these interrupted parts is important and must be maintained. or Continuous Flat (CF): meaning that the surface needs to be flat and smooth across the entire area, without any bumps or dips. The flatness must be consistent everywhere on the surface.

“CF” stands for “continuous feature.” This requirement is indicated when features need to be geometrically treated as a single feature. This note is referencing the dimensional interface of the mating parts. They are to fit and match dimensionally.

9. Tagging Method:

The documents specify identifying the Engine Bay Platform Assemblies as per drawing X201416739. Could you please clarify if the tagging should be done using a laser or a sticker or something else.

The platform is to be identified per MIL-STD-130, giving the contractor a variety of marking options. A method used on existing platforms is by tagging each section with a metal name plate or “dog tag” adhered or fastened to each “part” 1 through 3, including part number, section (forward, middle, or aft). For example, X201416739-30, Forward, Part 1 of 3.

Previous Vendor Questions

1. Is there a specific grade of plywood? ACX or CDX? Smooth, dry, dimensional stable ACX plywood.

1. Is there a specific species of wood? (typical build with group 2 includes Douglas Fir, Southern Yellow Pine for gov’t contracts) – not to be confused for grade 2. Prime Grade (1), smooth, dry, Douglas Fir, Pine OK for weight savings.

Notes #4 and #5 – What type / spec of rubber – and how should it be fastened onto the wood? SBR or neoprene traction mats, ribbed, textured, non-slip surfaces, approximately ¼” thick. Fasten using best practice, adhesive or staples acceptable.

1. Note #11 – What direction is forward? The -30, detail 1 is the forward section.

1. Note #12 – is there a preferred hole size? Sufficient to clearance the correctly sized allen wrench, approximately ½ dia.”

1. FN #13 and FN #14 – what type of plastic / plastic spec? Impact resistant plastics, Acetal, UHDPE, Polycarbonate or ABS.

1. FN #20 – What steel material / spec / coating requirements? Mild Steel, Acrylic or polyurethane with suitable primers.

1. FN #29 and FN #30 – is there a specified hinge? or any other requirements? FN #29- medium duty piano or equivalent. FN #30 - Heavy duty door hinge (3-hole OK) or equivalent.

1. Sheet 6, detail F shows a 135 degree angle – this is a hinged part – is it supposed to be fixed or limited at 135 degrees? (the hinge will allow it to move anywhere from 0 degrees to 180 degrees) 0 to 180 degrees, limited to 180 degrees.