So, for the last couple of months, I've been working on a saber with an FDM 3D printed removable core, and a 3D printed pommel, to fit an all aluminium hilt. Last weekend, I finally got around to soldering it up, and things were a little... underwhelming, shall we say. Aside from a bit of Arduino troubleshooting, the main thing that I noticed was that even at full volume, the usual 28mm speaker makes my Saber sounds fairly quiet compared to my other sabers. Now, I left a fair amount of space between the chassis and the pommel for a resonance cavity, but it barely seems to have any effect.
After scratching my head for a while, I suspect that the resonance cavity being made entirely of PLA is having a negative effect on the sound. my guess is that the steps created by the FDM printing process, even with a fine layer height (0.1mm, in theory) is creating a series of baffles that is muting the sound waves. That, or the PLA just doesn't resonate as well as aluminium does.
I'm not sure how to go about solving this problem. the obvious solution would be to machine a custom aluminium pommel, but as I don't have access to a lathe, that's (unfortunately) right out. I'm toying with the idea of plating the inside of the pommel with metal, or using some gap filling primer/bondo and sanding to smooth over the rough internal surface of the pommel.
Either way, before I started messing around, I thought it best to ask if anyone else has encountered this problem or anything similar, and if anyone has any solutions to offer.