Estimating chuck speeds

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LouStule
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Estimating chuck speeds

Post by LouStule »

I put a small yellow dot sticker on my lathe chuck and then used a tachometer app on my Iphone to estimate the chuck speed. I'm not convinced that the results were all that accurate. I don't have a belt/speed chart for my lathe. Are there any good methods to figure out how fast your lathe is spinning? Thanks.
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tornitore45
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Re: Estimating chuck speeds

Post by tornitore45 »

Look at the Motor Nameplate it shows the RPM most likely 95% x Line frequency X 60 / No of Pole pairs (either 1 or 2)
Typically 1750 RPM

Then measure the pulley Dimeters or gear ratios.

Try a reflective sticker possibly on all jaws
An unsophisticated app may get confused by the flicker of the jaws and count Jaws/minutes instead of RPM or be so crappy to just dream up some number since crappy software is the rule rather than the exception.
Mauro Gaetano
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John Hasler
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Re: Estimating chuck speeds

Post by John Hasler »

LouStule wrote: Tue Sep 15, 2020 5:51 pm I put a small yellow dot sticker on my lathe chuck and then used a tachometer app on my Iphone to estimate the chuck speed. I'm not convinced that the results were all that accurate. I don't have a belt/speed chart for my lathe. Are there any good methods to figure out how fast your lathe is spinning? Thanks.
Put a piece of 2" black pipe or similar in the chuck. Put the sticker on that.
LouStule
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Re: Estimating chuck speeds

Post by LouStule »

The app is basically a strobe light that you adjust with a slider until the rotating dot appears stationary and then the app displays the speed. Maybe I should borrow my buddies real strobe light and see if I can make my own belt/speed chart.
LouStule
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Re: Estimating chuck speeds

Post by LouStule »

John Hasler wrote: Tue Sep 15, 2020 7:09 pm
LouStule wrote: Tue Sep 15, 2020 5:51 pm I put a small yellow dot sticker on my lathe chuck and then used a tachometer app on my Iphone to estimate the chuck speed. I'm not convinced that the results were all that accurate. I don't have a belt/speed chart for my lathe. Are there any good methods to figure out how fast your lathe is spinning? Thanks.
Put a piece of 2" black pipe or similar in the chuck. Put the sticker on that.
Good idea!
John Evans
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Re: Estimating chuck speeds

Post by John Evans »

Welll according to the pictures you posted of your lathe in the other thread you HAVE a speed chart!! With standard pulley setup those lathes went from 28 to 2000 spindle RPMs. 2 ranges of motor to countershaft and 4 on the spindle plus backgear.
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tornitore45
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Re: Estimating chuck speeds

Post by tornitore45 »

A strobe light can give harmonic results. The dot is steady at the RPM but also at 2 X RPM
Mauro Gaetano
in Austin TX
armscor 1
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Re: Estimating chuck speeds

Post by armscor 1 »

20 Bucks on Ebay, LCD display with a magnet and sensor.
Use this on my Lathes and Mill, all have VFD'S.
Easy.
LouStule
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Re: Estimating chuck speeds

Post by LouStule »

John Evans wrote: Tue Sep 15, 2020 9:06 pm Welll according to the pictures you posted of your lathe in the other thread you HAVE a speed chart!! With standard pulley setup those lathes went from 28 to 2000 spindle RPMs. 2 ranges of motor to countershaft and 4 on the spindle plus backgear.
Are you sure you are looking at my lathe? I don't see it anywhere. Plus, I want to verify the chuck speed at different belt/pully arrangements. Thanks.
LouStule
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Re: Estimating chuck speeds

Post by LouStule »

armscor 1 wrote: Wed Sep 16, 2020 6:16 am 20 Bucks on Ebay, LCD display with a magnet and sensor.
Use this on my Lathes and Mill, all have VFD'S.
Easy.
I found it. It looks like a perfect solution. Thanks!
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Steggy
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Re: Estimating chuck speeds

Post by Steggy »

LouStule wrote: Fri Sep 18, 2020 6:41 pm
armscor 1 wrote: Wed Sep 16, 2020 6:16 am 20 Bucks on Ebay, LCD display with a magnet and sensor.
Use this on my Lathes and Mill, all have VFD'S.
Easy.
I found it. It looks like a perfect solution. Thanks!
Found what? Do you have a link?
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ctwo
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Re: Estimating chuck speeds

Post by ctwo »

I think the search term is

hall tachometer

and a quick demo (there is another yootoob video showing a complete install on a mill)

https://www.youtube.com/watch?v=6AFuz_HkO8M
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