How many POUNDS of the good stuff have you put on that so far? Only Reason I can see for the build. Not like you’re weighing babies after birth… oh and send me a pound too…

what the heck is it??

Well, this is an idea that is all kinds of bad for reasons that admittedly aren’t readily obvious.

For reference, I work in the scale industry.

Perhaps the most chilling (or stupid) part of this is the bit at the end about finding a manufacturer. Here’s a clue: the first thing you will need to do, whether you find it aesthetic or not, is print “not legal for trade” in some place where it is prominently visible when you are reading the “display.”

You don’t get to not do this. It is very illegal almost everywhere to build a scale, much less to market it, without placing a prominent notice that it has not undergone the usual testing and calibration procedures.

There is long-standing reason for this; it’s always been more profitable to build a cheating scale than to supply product at better cost. So modern industrial countries get a bit picky about the tech. The ancient egyptians deified scales (in person of the goddess ma’at) because of their role as revealer of hidden truths, but they can also be the teller of hard to reveal lies if misused.

I won’t even get into all the things that would be wrong with this design if it were meant to perform more than a decorative function; the bearings in casters are not up to the job of substituting for pivots and bearings, nor are the rolling surfaces of casters dimensionally stable enough to be trusted in this function.

Scales are very subtle; if they’re properly working they don’t move much and things can easily go wrong with them that aren’t immediately obvious, but cause their readings to become totally whacked. My job has gotten me hauled into court more than once over such things.

Build it as a toy if you want, but make very sure nobody ever thinks it’s anything other than that.

as a functional scale, it is very simplistic and not very accurate, but having 2 daughters that love to try things on their own, this is wonderful! kids love to get involved in my projects and love to help. I gave my oldest (12) an old VHS camcorder so she could do her own documentaries. homebrew and antique is great for kids, cause no one else at school has anything like it.

kudos on the scales!

So why this “hack” isn’t described as merely kids’ playground, as a demonstration of working principle?

And no, calibration here almost has no sense, unless you don’t mind of having an accuracy of ~3 kg. (FIY, calibration also involves non-trivial switching between various loads, and I’m sure that this thing will behave differently after (unloaded) => 10kg w.r.t. 6kg => 10kg.) If you ever disassembled a commercial scale, you already saw how sturdy and simplistic those pivot points are — minimum possibility of deformation, wobbling, etc.So why this “hack” isn’t described as merely kids’ playground, as a demonstration of working principle?

And no, calibration here almost has no sense, unless you don’t mind of having an accuracy of ~3 kg. (FIY, calibration also involves non-trivial switching between various loads, and I’m sure that this thing will behave differently after (unloaded) => 10kg w.r.t. 6kg => 10kg.) If you ever disassembled a commercial scale, you already saw how sturdy and simplistic those pivot points are — minimum possibility of deformation, wobbling, etc.

I like the clever pivoting system made of casters. I’ll have to try to commit that one to memory for future projects.

I would replace the wood counter balance, though. It would have to be adjusted based humidity change.

Guus, i looked through your websight, did see a lot of neat ideas, I like the coat hanger/cloths pin light. way cool and love your work. I’m happy giving my kids old laptops to play with. keep up the good work!

So, all the big mouth people with their accuracy talk and highwindedness, let’s see some links to a scale you made from an inverted table leg and some furniture wheels and using bolts only to connect stuff why don’t you.

And no this not a hack…… sure it isn’t…