Hacker News Reader

Comment by Animats | Hacker News Reader

Is Samsung making washing machines without out-of-balance detection? That was figured out by 1960. Today, a 3-axis accelerometer chip is $0.86, quantity 1. If a microprocessor is running the machine, the way it should operate is to back off the spin speed if it detects excessive vibration. As water drains out, the maximum speed at which vibration appears should increase. If that doesn't happen, shut down and sound the out of balance alarm.

View on HN

Mine is later than 1960 (but not by much), with all-mechanical controls, and I don't think it has out-of-balance detection since it will jump around and make loud banging noises long enough for you to notice and stop it. It's happened to me once or twice. A search of the Internet for "walking washing machines" reveals that this isn't uncommon, and there are many others discussing the balance problem with stories of machines moving several feet and shaking loud enough to be heard throughout the house --- but not any mention of "explosions", and very little mention of similar damage to the machine or its surroundings.

That really makes me wonder what's happening with these Samsungs --- the article has quotes like these...

One Georgia mom was pulling clothes from the dryer, with her 4-year-old son nearby, when she heard the boom and saw the damage.

...which make it sound like the machine was behaving perfectly normally, and then spontaneously self-destructed with no signs of vibration beforehand. That is very unusual. Even in the destructive videos on YouTube where the machine is deliberately unbalanced with an extremely heavy piece of non-clothing, they still shake loudly and viciously for some time before disintegrating.

> it will jump around and make loud banging noises long enough for you to notice and stop it. It's happened to me once or twice.

My first thought was https://www.youtube.com/watch?v=t2WmpsrVrTg

I'm surprised there's not a regular event.

If you buy sorbothane pads and put them underneath the washer's legs, they will dampen the vibrations and prevent it from walking.

I've a Samsung washing machine, and it usually spends about 15 minutes dicking about, spinning slowly in random directions, before actually starting to wash clothes. If it can't balance the clothes, it complains loudly. I've rarely ever heard it knocking while spinning dry.

Granted, it seems European machines are smaller and faster compared to US so maybe they spend a little more effort here, becase they would explode if misbalanced and spinning at 1400 rpm.

But if there's a bug in the software, all bets are off.

This is really what concerns me about their patch for the Note 7 that attempts to reduce the chance if the battery exploding by limiting the charge to 60%. We've go no reason to trust their software engineering any more than their hardware engineering.

I think the reason for the 60% limit is to "motivate" users to do the exchange, not to prevent the failure.

Maybe the problem is not the missing technology but just about finding the right balance between preventing explosions and keeping the machine running. If the machine plays it too safe, consumers are likely not satisfied.

Reply on news.ycombinator.com