How to read bandsaw speed?

[Bill Gruby]

I didn't say the method was no good, I said it maybe a problem as the line flashes by in a very short time. Further more If I recall the question was how to determine band speed without calculations!

What I said was no good was the chart in the link if 60 flashes/sec were used! In the write up the author claims florescent flashed at a 60 flash/sec rate which is wrong! And if the chart is calculate on that rate it too must be wrong!

It seem to me everyone was off topic and your laser checker was the only on topic answer alnog with me and Rbeckett offering a cheaper way.

Frank;

My challenge has nothing to do with lights or even a tach, and it is NOT off topic. It has to do do with you simply putting a line on your blade and tell us whether or not you can see it when the blade is moving. According to your previous statement it moves too fast to be seen. This will either prove us or you wrong. I can see it on all three of my saws.

"Billy G"

 

[Bill Gruby]

Taking into account that this is a Hobby Forum not an Aero Space Forum. this method would give a ballpark figure that could be used by the Home Shop Machinist, correct. Remember also that three professionals have said that they have used this method with success. So I am asking you again could this method be used with some success. No samantics, just a yes or no is all I want to see. I already know why it is used.

"Billy G" :nono:

PS -- I don't look at the stop watch when using it. I just press start then stop when I see the line a second time. Then I look at the elapsed time.

One very important thing here Frank, a good machinist is not rated by the number of nor the manufacturer of his equipment. It is the end result using the equipment he has. Yes I have the hand tachs by both Starrett and B&S. You know, the ones that look like a pregnant fish. I also have a Hasler Bern. Somebody forgot to tell you That I am also a collector.

 

[Tony Wells]

I am modifying a bandsaw to slow the speed down.
Other than doing the math - motor speed X pulley ratios etc - how can one determine the blade speed?
Is there a way to read it directly?

Actually, the math referred to in the OP is NOT required for this method, and therefore does fulfill the request.

 

[Bill Gruby]

I will accept that Frank, thank-you. Most of it anyway. You see without having the set-up that Steve has we answered the original post the best we could. So in all fairness, yes we answered the first post. He said is there another way, that can be answered YES or NO.

There were no wrong answers givin on this thread, just some very clouded ones. :lmao::lmao::lmao::lmao::lmao::lmao:


"Billy G" :whistle:

 

[Hawkeye]

Steve, the diagram you posted shows the older magnetic ballast. It will indeed produce the 120 flash/second result.

While an incandescent bulb won't give a clean flash like a discharge lamp, it does 'wobble' enough to be detectable. I have an optical tach I built years ago for tuning RC engines. The tach is calibrated by aiming it at an ordinary light bulb running on 60 Hz AC. The scales have bugs marked at 3600 RPM for calibration (60 Hz x 60 seconds/minute). And before anybody goes all "Yeah but" on me, all my planes have 2-blade props - 2 pulses per revolution, just like 60 Hz AC.

I just tried an experiment. I aimed the tach at a newer fluorescent fixture. It read 3600 RPM on both scales. I would have expected a higher reading if the electronic ballasts were running at a higher frequency. So newer lights may actually work fine with that scale.