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View Full Version : Digital Photo Laser Tachometer check Motor RPM


PNracing
2011.01.24, 06:47 PM
I bought this item from Amazon.com to test my 33T motor

Input 4.8V 43000rpm
In the Mini-Z with battery full throttle output around 5.3V 48000rpm
Tape the white stickers in the tire, gear ratio 5.73, full throttle is 7700rpm

http://www.amazon.com/gp/product/B001N4QY66/ref=ord_cart_shr?ie=UTF8&m=AFLT987H7WA7G

blt456
2011.01.24, 07:32 PM
Cool, thanks Philip! Time to test out my handwound motors :)

lfisminiz
2011.01.24, 09:25 PM
Philip,

Nice find...will check it out.

EMU
2011.01.24, 10:24 PM
Thanks for the info Phlip.

Are you calculating the motor RPM from the wheel RPM, or measuring from the motor itself? I was thinking about getting it, and glueing a pinion inside the hub of a wheel to take the readings....

PNracing
2011.01.24, 10:50 PM
Thanks for the info Phlip.

Are you calculating the motor RPM from the wheel RPM, or measuring from the motor itself? I was thinking about getting it, and glueing a pinion inside the hub of a wheel to take the readings....

The last testing to check the Wheel RPM, then you can compare the car speed with others.

HaCo
2011.01.25, 10:38 AM
There are cheap ones on ebay too!

arch2b
2011.01.25, 11:51 AM
atomic (http://mini-zracer.com/forums/showpost.php?p=402259&postcount=268) has something very similar if not the same thing. just in case this was not picked up on when posted.

bermbuster
2011.01.25, 12:39 PM
Thanks for the info Phlip.

Are you calculating the motor RPM from the wheel RPM, or measuring from the motor itself? I was thinking about getting it, and glueing a pinion inside the hub of a wheel to take the readings....

all you need is a large pinion to attach the reflective tape too...
a pinion from an overlandor mini monster will do. This way you get motor speed....
I made a hub from delrin.

bermbuster
2011.01.25, 12:40 PM
atomic (http://mini-zracer.com/forums/showpost.php?p=402259&postcount=268) has something very similar if not the same thing. just in case this was not picked up on when posted.

I dont know what the Atomic unit sells for but a non contact lasertach can be bought for under $20....and then you make your own hubs from old pinions etc....

arch2b
2011.01.25, 01:55 PM
don't disagree, just sharing information sai posted not to long ago on the very same technology.