I was asked to help the operators verify the speed of a shaft. I was told that they couldn't do it because their strobe read fpm only. Their strobe is a Shimpo DT 725. I pulled up the manual on the Shimpo website, but I didn't see anything that told if it could or could not be switched between fpm and rpm.

Are any of you familiar with Simpo strobes?

David Eason

David,
Actually we have 3 different types of the Shimpo Strobes; the DT 725, DT 900 and the DT 315a. Now the FPM on the display stands for flashes per minute, people sometimes confuse this thinking it means feet per minute.
Now for measuring feet per minute a tachometer with a contact wheel works well like the DT 207L.
Hope this helps.

Ken

David

I do strobe analysis training and the first thing you have to do is keep it simple.
Tell them fpm means flashes per minute.

Mark
alertanalytical.com

Har, har, har!!! This is good. I can't wait to go back over there and see those guys.

Thanks,
David Eason

David,

Once I witnessed a skilled millwright take a hand held tachometer with the meaasuring wheel on it and press it up to the surface of a paper machine lineshaft. He set it on rpm and read it as about 1900. I couldn't convince him that he was measuring the rpm of the wheel due to the surface speed of the shaft. Unknown to me, he reported it to the Plant Engineer who had requested the Line Shaft rpm in order to get a recommendation on what bearings would be needed for the future speed-up of the machine.

After much study, no bearing manufacturer could come up with a bearing that was economically feasible until I happened to talk to the Engineer and he asked me how fast the line shaft ran and I said usually about 300 rpm.

Good instruments in the wrong hands can be a dangerous combination.

David, before you laugh at these guys too much, could you explain how YOU thought a strobe could be calibrated in feet/minute?!?

Danny,
That's a good story.

Rusty,
I was afraid somebody was going to ask that question. My only defense (read excuse) is that they called and asked for help, so I grabbed my toys and went. I found out later what they had and looked it up on the net. It didn't seem right, but you never know what you can learn if you keep an open mind. That's my story and I'm sticking to it. Oh well, if a person can't take a laugh and even laugh at himself sometimes, he's living way too up tight.

David Eason

David, good attitude. I learned long ago that taking myself too seriously was a big mistake. Stay in this business very long, and sooner or later you will be wrong in a most embarrassing fashion... if you don't laugh about it, no one else will either.

This message has been edited. Last edited by: rustythevibeguy,

David, I have a customer that makes snack bags. If they are running a 12" bag, then the strobe light will actually be calibrated in feet/minute. So if the strip on the machine has a 12" repeat, then FPM is actually feet/minute! Hey, as the little boy says on Angels in the Outfield, "It could happen!"

Rusty,

I thought you would be reading in Bags/minute!

Walt

Rusty,
Thanks for rescueing me. Now maybe I won't look like such a goof.

David Eason

Talk about strobes in the wrong hands. I had a new employee working with me on a vibration route. I took a strobe and stopped a coupling to read the size. My helper said "cool" and reached for the coupling. I had to knock him back just before he touched it. It was the first time he had ever seen a strobe work. Now we often joke about stopping a coupling with the strobe so we can tighten the bolts. Watch your helpers and keep them safe.

Have a good one,

Gary B