About this part
BSD License. !!! DO NOT EVER, EVER, EVER! PRINT CAR PARTS WITH PLA !!! PLA WILL reach glassing temperatures on hot sunny days, no matter WHERE in the car the part goes. PETG, ABS, or other similar higher-temp filament is REQUIRED With that safety disclaimer now out of the way, a comprehensive write-up to answer every question you might have, before you even think to have it :-) FEATURES ADJUSTABLE DESIGN via OpenSCAD – if this doesn't fit your car, you can very easily change parameters as needed so that it does. File includes a TEST_FIT mode with adjustable height so you don't need to print off an entire bracket to confirm fitment. As currently coded, it's limited to three screw tabs for the car door itself, however you could jury-rig something up M3 or M4 speaker-securing bolt options, and an option to use either captive nuts or brass heated inserts as well! PLEASE NOTE: M4 heated insert dimensions must be supplied in the M4HeatsertDia and M4HeatsertDepth variables for this to work correctly. I've never used M4 so I don't have a good hole size offhand. Brass heated inserts are installed at the top of the bracket, while captive nuts are installed at the bottom. Both have fully pass-through holes for their respective bolts to go through. CLEAR AND COMMENTED CODE thanks to being a senior full-stack systems architect a.k.a. code monkey. No unhelpful variable names or confusing blocks of code here! :-) EXTRA PADDING FOR NUTS – ever see a design where the securing bolt holes are exactly as deep as the bolt is long, so the bolt could in theory scratch up whatever it's attached to? Or a captive nut hole that sits exactly on the same surface that's supposed to fit on something else? This avoids both issues, thanks to a 2mm-deep gap between the nut and the bottom of the bracket, and a 1-2mm gap between the bolt and the bottom of the bracket when using an MX Designs MX-7. DESCRIPTION Speaker adapter spacer bracket for a variety of Subaru vehicles with potential fitment for Toyota, Scion, and Lexus vehicles. The Metra 82-8148 bracket was ever so slightly too tight for the 6.8" CDT Audio “MX Designs” MX-7, so I decided to design and print this bracket off instead. Bolt pattern matches up exactly with Subaru part #86301AL61A – click here for a full list of Outbacks that fully confirmed to fit, and Legacy years/trims that the bolt holes are confirmed to fit, i.e. you still need to verify the mounting depth. The windows on the rear doors of 2015 thru 2019 Subaru Outbacks don't reach down far enough, but I can't confirm if the same holds true for the Legacy. This bracket MIGHT also fit additional vehicles (like Imprezas, Crosstreks, XV's, etc.) supported by the Metra 82-8148 bracket, however the Metra bracket bolt holes include slots that appear to fit variations that are slightly off, so I cannot confirm other makes/models. For all makes/models that the Metra 82-8148 fits and to see if the adapter has the potential to fit your car without modifications, click here for the MetraOnline product page with partial list of fitment applications and/or check Crutchfield's “Does it fit your car?” feature on their product page for the Metra 82-8148 here for a far more comprehensive list. Again, these are cars that it MIGHT fit due to the Metra bracket including slot holes for the screws and are NOT guaranteed to fit. TO FULLY CONFIRM, print off the “Test fit” STL and see if the holes etc. line up and screw in correctly. If it doesn't, thanks to the parametric design, it should fit a LOT more vehicles with minor tweaks :-) If you are using a different speaker, but the car door screws line up correctly, you only need to adjust any variables starting with Woofer_ -- do NOT forget to adjust Woofer_Ring_Depth with the mounting ring thickness in mind so that whatever bolts you use will still work without going through the bottom. It's currently set to 22mm, i.e. a mounting bracket thinner than 3mm will NOT work as the bolts will stick out the bottom and into the metal of the door frame. SPECIAL NOTE If you use captive nuts, you WILL need to use 25mm-long bolts!!! Brass heated inserts can accept up to 25mm in length, but no more than “long enough to be threaded in fully” is necessary. Wiring is behind-the-door ONLY – Due to differences in how speaker wiring can be run and the sizing of connectors thereof, I opted to force wiring to exit the back, and modify my Metra 72-8104 harnesses to use ferrules instead of spade connectors. I then took off the pop rivet securing the wiring to the front of the panel, fed it back into the door along the main harness, wrapped it around once or twice, and then into the speaker terminals. If you want to run wiring through the side of the bracket, you'll have to either boolean “difference” the STL itself (either in the slicer, by editing the OpenSCAD file, or making adjustments via other CAD software), or drill a hole where needed or file/dremel a slot where needed. For maximum strength of the part, print with three or more perimeters, five or more top shell layers, and enough bottom shell layers so that the car door screw tabs finish printing before the bottom shell layers are done. For the included setup – 4mm tabs @ 0.2 layer height, this amounts to OVER 20 shell layers. Remember, INFILL IS NOT STRUCTURAL!!! Plastic does not deform, it cracks, and infill has negligible impact on this. I wound up using 35 bottom shell layers, 5 top shell layers, and three perimeters. Remember, out of all the things 3D printing is used for, a 300W peak mid-bass woofer in a sealed door chamber pushing exactly in the Z direction where not only do the raw mechanical forces create a profanely easy ability for layer separation failures, but internal air pressures aid and embed them from the sides as well. This bracket is supporting a juggernaut of the worst kinds of destructive forces ANY 3D printed part can endure – the more solidified you make the part via shell layers, the more peace of mind you'll have that it'll never fail at all. While it might be overkill, I'm not willing to test and find out (especially with how said strength ages), and neither should you. Injection-molded plastics are one thick piece and not prone to failures as a result, whereas FDM plastics are an outer shell with some structurally-meaningless filler and a tendency to fail along the layers, which is exactly where the stress of this part is. If you read through all of the above in full without missing a thing, you're the kind of person I write this for! We all know most will skim, and that's why the emphasis is where it is :-) REQUIRED PARTS (for pre-configured STL, per door) 6 x M4 nuts 6 x M4 25mm bolts 3 x 1.25" #10 screws (as of V2) 1 x CDT Audio / MX Designs MX-7 and wiring Double this if you want to print two spacers (12 nuts, 12 bolts, 6 screws, etc.) CHANGELOG V1 - 2023-04-02 Original Upload V2 - 2023-08-24 Mounting tabs thickened to ~3/4" to increase strength, which now requires 3 x 1.25" #10 screws per ring. Thinner tabs of V1 had a tendency to snap off with higher loads. Fixed DXF generation and commented the relevant line to do so in the .scad file DXF uploaded – due to OpenSCAD generating polygons rather than true geometric cylinders, the DXF itself uses polylines. I do not currently have a way to fix this.