u/PAPaaaaJIIII

I’m designing an automated sliding door system for a small lab. The requirements are a quiet operation (under 40 dB), smooth acceleration and deceleration, a door weight of about 45 kg, a travel distance of 1.2 m, and reliable soft-start and soft-stop control. I’ve tested a brushed DC motor, but it is too noisy. A stepper motor gives jerky motion at low speeds, and a cheap BLDC motor produces inconsistent torque at startup.

I’m now considering either a BLDC motor with encoder feedback or a servo motor system. My main concern is achieving smooth motion without overshoot, vibration, or instability.

My 72-year-old father has had a hard time following television dialogue and group conversations for quite a while now. It has gotten so bad that he often just checks out during family meals because he misses so much of what is being said. The major hurdle is that he is extremely cheap. He visited an audiologist once, saw a quote for over $4,000, and immediately walked out the door. He stubbornly insists he would rather suffer in silence than hand over that kind of cash.

I am planning to surprise him with some Over-the-Counter (OTC) devices, but the market is completely flooded. Between Sony, Jabra, and countless cheap knock-offs online, I am lost. I desperately need something practically foolproof—ideally a set that doesn't require a complex smartphone app to function—but still provides clear audio so he won't just toss them in a drawer. Has anyone found an OTC model under $1,000 that a stubborn, tech-averse parent actually tolerated and continued to use?