Overview

These are common language which can be used to indicate certain processes during the manufacture of a part. The prefix indicates that any drawing note number may be used.

Machining

X. MACHINE PER BEST SHOP PRACTICE

This not is used when you don't actually care how the part gets made, as long as it is made to dimension. This leaves the exact method of manufacturing up to the machinist or technician. The alternative to this note is to specify a process in a drawing note or specification.

X. USE MCMASTER-CARR PN: (YYYYYYYYY) AS STOCK TO FABRICATE THIS PART

If you're making a firebolt, god-nut, or similar part which is a modified version of a COTS part, use a variation of this note to indicate where to get the part to be modified.

X. MACHINE FROM PN: ASNNN

Use this note if the part is manufactured from another Rocket Team part. For example AB101 (Payload Bulkhead) is machined from a waterjet blank which is part number AB101-M01, and the AB101 drawing would use this note.

X. THIS IS A DIGITALLY MANUFACTURED PART. ALL DIMENSIONS ARE FOR REFERENCE ONLY. THE CAD FILE SHALL BE THE MASTER FOR ALL DIMENSIONS NOT LISTED HERE.

Use this note if you're using CAM to make a part. This note technically lets you be lazy and only include a few dimensions for reference on the drawing. All dimensions must be reference dimensions if you use this note.

X. DRILL AND TAP PER UNC #4-40

This is a flag note which should be added before hole callouts with tapped holes, specifying the use of a unified national coarse thread profile, the team's standard.

X. SURFACE IS SEAL BEARING

Typically a flag note, this points out where an o-ring or gasket goes. These surfaces are extra important to pay close attention to.

X. BREAK ALL EDGES

This note requires all edges be deburred. This can be accomplished after manual machining or as part of a CNC operation. The chamfer is typically not modeled.

Part Marking

To maintain traceability, every manufactured piece needs a part number and a serial number. These notes are usually flag notes calling out where to apply the part mark. The aerospace standard controlling part marking is AS478, and is available through MIT libraries.

X. MARK PART NUMBER AND SERIAL NUMBER PER AS478 4.1.15

Use this note when you want to laser etch the part mark in. Works well on anodized aluminum and some composites.

X. MARK PART NUMBER AND SERIAL NUMBER PER AS478 4.1.7.4

Electro-etch the part mark in. Requires a vinyl mask, a current supply, and an electrolyte solution (salt water usually). Works well on stainless steel, unanodized aluminum and titanium.

X. PART IS MARKED PER AS478 4.1.1 ENSURE INFORMATION IS UPDATED PRIOR TO FABRICATION

4.1.1 is the 'integral' part mark and would be used when you cast a part with the park mark, machine in the part mark or 3d print an embossed part mark. You need to ensure you have updated the serial number and part revision prior to printing.

Finishes

X. ANODIZE TO CLASS II, TYPE 2 (COLOR) PER MIL-A-8625F

This note specifies a colored anodize. This note may be amended to specify a minimum or maximum coating thickness.

X. ANODIZE TO CLASS III PER MIL-A-8625F

This note specifies a 'hardcoat' anodize which is thicker and tougher than a normal anodize, and has a dull gray color.

X. PRIME, FILLER, AND SAND TO FINISH PER BEST SHOP PRACTICE

This note gives the manufacturing individual broad authority to apply primer, bondo, and sand in layers to achieve a good surface finish. This note may be amended to specify that the substrate (underlying) material may not be sanded into, or the number of layers which may be sanded into (important for composite laminates)

X. PAINT RED

Duh. May also specify a pantone color, a brand of paint, a minimum paint thickness, or similar. Can include masking instructions

X. APPLY CLEAR COAT

May specify a brand or chemical formulation of clear coat.

Testing

X. TEST PER MIT ROCKET TEAM FIREBOLT HYDROSTATIC TESTING PROCEDURE

Any Rocket Team standard or document on the wiki may be called out as additional procedures to follow while creating a part.

X. VERIFY RESISTANCE OF AT LEAST (OR LESS THAN) XXX OHMS

Flag note identifying two sites to perform a resistance check across. Useful for ensuring avionics/e-matches aren't accidentally contacting each other.