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(/member/orksecurity/)
3 years ago Reply (C5BGGTIGLWQX8OU)
(/member/LiquidLightning/)
2 years ago Reply (C3P1T02GUCF4O5R)
(/member/rickharris/)
3 years ago Reply (CUOSHM3GM552H4X)
(/member/orksecurity/)
3 years ago Reply (CWWAFIWGM7E9ZQB)
is there any way to measure rpms cheaply?we are making wind
turbines in one of my classes and my team is making a teslaturbine
as ours. we want a way to measure how fast the disks are spinning.
pleasehelp.
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orksecurity (/member/orksecurity/)
Attach a gear to the shaft. Hold a card against the teeth of the
gear and listen for themusical note produced. Find that note on a
piano. Look up or calculate itsfrequency to get teeth per second.
Divide that by number teeth on the gear to getrotations per second.
Multiply by 60 to get rotations per minute.
Not hugely accurate, but you're looking for cheap rather than
precise.
LiquidLightning (/member/LiquidLightning/) orksecurity
Creative!
rickharris (/member/rickharris/)
put a white dot/bar on the disc, look at it with a photo
transistor. the output willbe proportional to speed.
IF you can attach something to the spinning shaft then a DC
motor will give anoutput proportional to speed - all you need is to
calibrate it.
orksecurity (/member/orksecurity/) rickharris
Photodetector does have theadvantage of minimum added dragon the
system.
seandogue (/member/seandogue/) rickharris
q=tesla+turbine+school+RPMs+wood+workshop+wo
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About This Topic
Posted:Apr 6, 2011
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(/member/seandogue/)
3 years ago Reply (C0O6CP1GM552HO6)
(/member/LargeMouthBass/)
3 years ago Reply (CQCUH8EGM4N19DW)
+1
LargeMouthBass (/member/LargeMouthBass/)
If you are willing to spend a littlemoney, you could get a
device likethis one, which sells for $30.
http://www.harborfreight.com/digital-contact-tachometer-66400.html(http://www.harborfreight.com/digital-contact-tachometer-66400.html)
I have an older version of this device,and it has proven handy
onoccassion. You basically hold theshaft up to the shaft you want
tomeasure. The device comes withvarious tips to help couple to the
shaft.
I don't know much about Teslaturbines, but I believe that
theytypically operate at high rpms. Thedevice at the link above
claims towork to 20000rpm. I have only usedmy meter for speeds of a
fewthousand RPM.
If your measurement also has to beused as feedback to some
otherdevice, then you would be best usingan approach like those
suggested inthe other answers.
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DehLeprechaun(/member/DehLeprechaun/)
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