Low Shelf Pocket Block

generate an actual .STEP file—and export the CAD to use in Fusion360 So, I can walk through modeling this quickly in Fusion 360, ## Quick Fusion 360 Modeling Steps **For the Low Shelf Pocket:** 1. **Create a new component** for your lower receiver 2. **Sketch on the XY plane** (top of receiver): - Draw a rectangle centered on origin - Width: 1.250" - Length: 1.800" (or match your specific lower's FCG length) - Position rear wall at X = -0.100" (behind takedown pin) 3. **Extrude Cut downward**: - Distance: 0.625" - Direction: -Z 4. **Add corner fillets**: 0.125" radius on vertical edges 5. **Cut selector hole**: - Center at intersection of pocket centerline - Diameter: 0.375" - Through-all **For the full lower**, you'll also need: - Pistol grip threads (1.250"-18 UNEF, depth ~0.600") - Buffer tube threads (1.1875"-16 UN, depth ~0.750") - Takedown/pivot pin holes (0.250" diameter) - Magazine well geometry ## Open Source Resources You can find existing open-source lower receiver CAD files that you can modify: - **FOSSCAD Repository** - Has various lower receiver designs in .STEP format - **Deterrence Dispensed** - Open-source firearm CAD files - **Ctrl+Pew / Are We Cool Yet** - Hosts open-source lower designs **Machining note for 7075-T6:** Use carbide end mills, aggressive feeds/speeds (7075 machines well), and consider leaving 0.010" finish passes on critical surfaces like the pocket floor. The fire control group needs a flat, smooth surface to function reliably.

Parameters

Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.