My suggestion would be to buy some of the scales which operate in your rangeand sell for about $10 on ebay, and try to hack into their circuit somehow.Otherwise, it doesn't seem like an easy problem. There are force sensors thatexist, I don't know how sensitive they are, and you would have to rig somekind of platform on top of them to hold the object being weighed, and thencalibrate it somehow. Doesn't sound very easy.
However, their precision in that price range is a little lacking.
QuoteHowever, their precision in that price range is a little lacking.Not sure why you think that. Think you can do better ?
But since I found a $7 load cell as a component with known specs and that meets my requirements, I think that's a better option than going with an unknown salvage.
Quote from: michinyon on Jan 26, 2013, 07:53 amThe other components of the project will be a geared-down DC motor to rotate a dispensing tube, and there will be an automatic dump when the correct weight is achieved.Go to a gun store and buy a powder trickler.
The other components of the project will be a geared-down DC motor to rotate a dispensing tube, and there will be an automatic dump when the correct weight is achieved.
because I require 0.005 gram precision
Measuring weight isn't that difficult: a strain gauge for example.Measuring mass is very challenging, electronically.
and the $10 scales I found provide 0.1g or 0.05g precision.