Although it feels like meat grinders have been around since the beginning of time, they are a relatively new toy. The first one was built in the 19th century, by Karl Drais; the same guy who created the velocipede - a proto-bicycle.
Every time I have to use one of these, I am facing the meat grinder's dilemma. In plain English:
Which way does the knife go in?
Aaaaah! You've been there too, haven't you?
It doesn't matter if it is an old-school hand-powered unit, or a fancy electric one, they all share a design flaw - only one of the 2 ways to assemble it is right.
If the knife is plugged in the wrong way, the meat won't be minced properly, while the machine will continue to work as if everything is fine.
There are several ways to solve the problem:
- Empirical - install it one way, then turn it over if you see that it doesn't go well;
- Theoretical - try to figure out how the blades will rotate and how they will interact with the rest of the machine and the meat.
Last time I faced this dilemma, my enemy was a Bosch meat mincer, which had two deceptive solutions to this problem:
- The sticker - a large one the front of the machine. My mom decided to keep it there, fearing it won't peal off without leaving traces (if you're reading this on a laptop, take a look at your keyboard and you'll know what I mean).
- The shape of the metal - the knife has a hole in the form of a frustum (think of a pyramid with its top sliced off). The cylinder to which it is attached has a base of the same form - so they look like they should "click" together.
The sticker was useless, as it depicted many things, except a diagram of how to install the knife correctly. "Frustum on frustum" appeared to be the only logical solution.
Moments later, my dad showed up and mentioned the "obviously right way" to install it, which was the opposite of what I thought. He made a point by emphasizing "obviously". I politely reminded him that just 6 minutes ago he was asking me about which button to click in a program he was using; I answered his question without using the word "obvious", but I digress.
Having thought about it, I figured that there is a simple solution to this problem. Take your time to think about it before moving on. Really, don't read further until you think of a way to fix this.
- Feedback - make a buzz or turn on a light if the knife was positioned incorrectly. It is too complicated and it increases the cost of the unit, it also adds multiple points of failure. Once the signal is generated, the person using the machine will realize something isn't right, but they won't know what exactly is wrong and most importantly - they won't know how to fix it. The assumption that they read the manual before using the machine is a bad one.
- Information in the interface - replace the sticker with a helpful one that shows how the knife must be placed. This is much better than forcing people to keep the information in their heads, or read the manual every time prior to using the mincer.
These solutions are only partial, because they still make it possible to install the parts the wrong way.
A better solution is to add some asymmetry and eliminate the problem altogether. Add a little pimple to the base, and make a little hole in the knife - such that it "clicks" when installed correctly, and it remains tilted when set up the wrong way. By adding a constraint to the design, we make it obvious which way it should go.
There's no need to have a degree in contact mechanics and friction to figure out how that works. As an added bonus, the meat mincer designer won't go to bed wondering "how many people use my product the wrong way and are unaware of it?".
Comment from: Constantin [Visitor]
had the same technical issue about a week ago :)
although I didn’t make a big fuss over it, I chose the empirical way and in less than a minute had it installed correctly. nevertheless I had to go through the theoretical stuff as well, since my wife totally disagreed with me on this matter (for her, putting the knife the other way around made much more sense :).
there has to be a way to report this bug :)
i didn’t read further after you said I shouldn’t. you know, this was as other-wordly as your programming posts:) I’m vegetarian. (comment contains hint on how to solve the dilemma)
Comment from: gr8dude [Member]
Well, if one of your non-vegetarian savage friends ever asks you to assemble one of these killing machines, you should know that the blades must be close to the thing with the holes.
Otherwise, continue operating in non-vegetarian mode :-)
i’ve noticed the smiley, but still, to make sure: i didn’t imply that the non-vegetarian mode implies savageness, barbarity, a penchant for mass murder, an awful taste in music, bad breath etc etc:)
my friends know better than to charge me with practical tasks. in highschool my clique was drawing utopian plans to move in together, the lot of us, into a house with a nice view. it was said that X. would express her artistic genius by decorating the place, Y. would delight us with her cooking, Z. would be in charge of administration, and m….well, m. would better just stay out of the way and watch tv or something.
:) The anti-spam word is “Cannibalism”
Comment from: gr8dude [Member]
Your story reminds me of “Never let me go” (there’s a book and a movie), the names of the characters were in the form “First name, first letter of last name", such as “Kathy H.” or “Tommy D.".
At some point, they moved out into houses where they lived on their own.
yeah, i keep hearing it’s less than stellar. apparently The Remains of the Day is still Ishiguro’s best work. I’m not sure I’d want THAT book to be the story of my life, though. on the other hand, whether it would make a good novel is a fair enough test of how awesome a life has been.
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