I received a request to repair a vintage Neumman U87 in non-functioning condition that had unfortunately been abused by students in an audio program for 20+ years. The capsule carrier plastic was completely shattered and the capsule couldn’t attach to the main body of the mic. Fortunately, the electronics are in great condition, so it’s just a matter of cleaning the capsule and restoring the plastic pieces.

I back-engineered these 3D-printable parts and you can find the files here:

3D printing STereoLithography (stl) files

TOP U87 CAPSULE CARRIER PLASTIC .STL

BOTTOM U87 CAPSULE CARRIER PLASTIC .STL

3D CAD STEP files

U87 CAPSULE CARRIER PLASTIC (BOTH PARTS) .STP

• I used PLA, 100% infill, and it’s quite strong. Supports are a must, so make sure your support settings are dialed in. Alternatively, you could use a site like Xometry and sinter them from Nylon if you don’t have a 3D printer or want a stronger material.
• The capsule pin holes I put at 2.4mm, even though I measured a 1.5mm hole. A few reasons: I’m going to use the original pins and JB-weld them in place. Also, my 8-year-old old FDM 3D printer kind of sucks, and I intentionally oversized the holes because my printer tends to print through holes about 10% small.
  Alternatives include shaping some brass socket head cap M1.6 or M2 screws, or brass pin nails, but that would require a different hole size. I’ve included the STEP files as well so you can modify them rather easily.
• I’m doing something similar for the riveted-in switches. I had to drill out the old rivets. Instead of tube riveting and cracking the old plastic on the switches, I’m going to use the old rivets and JB weld those in as well. I also thought about tapping in new plastic-threaded screws, but I’m worried I’d break the old plastic on the switches, which already is showing some fatigue.
• I’ll probably tap in an extra set screw or two to hold the capsule rubber in place.
• This is for the opaque plastic of the early 70s mics. The clear plastic ones are a bit different.

if you have a vintage mic that needs some TLC, shoot me an email – derek@vanguardaudiolabs.com!