Handheld Tachometer - Laser & Contact - Review & Demo

[@millie19301]

Ron, another great video. I appreciate the things you test, Cheers!

[@stevel227]

Ron ... If you want a new tachometer project, it is pretty easy to add a digital-readout tach on the front of your drill press. I built mine using a Hall proximity monitor triggered by a button magnet epoxied to the underside of the drill press pulley attached to the chuck. The proximity monitor sends a counting signal to a counter/clock mounted on the front of the drill press head. Easy peasy, and pretty cheap.

[@victork3397]

I’d love to see a video of this in action and how you put it together

[@Robonza]

Hey Ron, good to see a new video. If that tape is retro reflective you may find you get better results holding it farther away. Also with the lights off you may get cleaner results too.

[@RonaldWalters2010]

Good advise. Thanks! Ron

[@Chris_Grossman]

When you use the contact tachometer you are putting a small load on the engine and I would expect a slight reduction in speed. Just because you got a different reading does not make either one wrong.

[@thenri99]

What makes you say the contact tachometer is more accurate? I would expect that the contact induces a small load on the engine which slows its speed, so I would expect the laser tachometers to have a more accurate reading (~2000 rpm) because the act of measuring affects the phenomenon less.

[@AlloyedFrequencies]

Don't you get a wrong reading for rpm when the shaft is a different size then the piece on the tachometer? thank you

[@RonaldWalters2010]

No, not as demonstrated. The "rubber cup" on the end of the tachometer centers itself on the motor shaft so the motor shaft and the tachometer shaft are concentric with each other... turning on the same centerline. You do need to hold the tachometer parallel to the motor shaft while taking the reading. Thanks for watching. Please subscribe! That is what keeps this channel running. Ron

[@XPFTP]

how far from wheel do you have to be for it to be right? i testing a 12hp motor and 6 inchs was way high. far away was closer to idle rpm.. like 2ft away. its with the 12 buck one in this video.

[@RonaldWalters2010]

As you see in the video, I am fairly close to the flywheel. Measuring off a larger diameter will give better results (a pulley rather than a motor shaft). A non-reflective surface with the reflective tape will be more accurate (a reflective or polished surface will reflect the laser as does the reflective tape, giving some false readings). 2 ft away is probably too far away. If you can rest the tachometer on a solid, non-vibrating surface it will give better readings than trying to hand hold it and it is being waved around a bit (the steadier the better). Think of it as looking through a rifle scope... only as accurate as it is being held steady. Also, the tachometer needs to be held square to the rotating surface (square in both directions). The more accurately (and steady) you hold the instrument the better the readings will be. Usually, the closer the better (as long as it is safe to do so) as fewer false reflections should be detected. Truth be known... I still prefer the old fashion, analog, contact tachometers. Thanks for watching. Please subscribe. That's what keeps this channel going! Ron

[@XPFTP]

@@RonaldWalters2010 went out to retry how i was doing it.. after you saying about the reflective surfaces. found it worked much better. also sun light doesnt help to much lol... but i wish i could use contact rpm. but old kohler 12 hp motors sort of tough to touch anywhere to get reading.. be nice if someone made a tach for 1 cyl motors. but ty for responding and info it helps for sure.. good vid..