Good morning all,
What sensor would be best to use to get a length measurement?
I have screws that need to be separated into two categories, ex Length A or Not Length A.
The screws are small, thread major around 1mm and OAL ranging from 6 - 20mm.
The screws will be introduced one at a time and standing still when the measurement needs to be taken.
I have thousands to sort through so a simple "use a caliper" is not going to help.
Is ultrasonic feasible for this?
Is there a laser or something else that would be better?
I'd use a hall sensor + permanent magnet installed close to screw passing. Then alteration on magnetic field caused by the size of the screw 'd depends on size, and you can read from hall sensor by arduino.
assuming the screws are stood on end or hanging thru a plate or conveyor use a proximity sensor
It would seem to me that if you have the mechanism to arrange them nicely in order to be measured then you could just roll them over a series of increasingly longer slots such that the smallest ones fall into one bin, next largest into another bin and so on. No actual length sensor needed. Perhaps I don't understand the problem...
rw950431:
It would seem to me that if you have the mechanism to arrange them nicely in order to be measured then you could just roll them over a series of increasingly longer slots such that the smallest ones fall into one bin, next largest into another bin and so on. No actual length sensor needed. Perhaps I don't understand the problem...
You're definitely right. Infact I did just this to sort those screw, simple mechancal mechanism.
I have a little bit of a harder task now, same thing sorting screws. Very tiny though. 3mm head diameter, 1.5mm major diameter, 3.5 and 4mm overall length. Just the two screw types, only difference is the .020" on the tip. The head diameter being so large and the length of screw so sort, the previous method can't work, the staggered distance between rails can not be long enough to let the head pass, yet still make contact with the body of the screw. These damn things are tiny!
tl;dr anything that can sense a length change of .020"?