Spindles...runout...solutions

[John Hart]

Hey ya'll....I just made a discovery. My lathe has a 1"-8 TPI spindle and folks were talking about putting a nylon washer on the spindle to resolve some runout and wobble problems with their chucks and faceplates. Well, one of my technicians was tearing up some old hard drives the other day and asked me if I wanted some of the magnets and other various parts to play with. Well, each hard drive platter is held in place by aluminum washers that happen to be exactly 1" on the inner diameter. They are precision washers....perfectly flat...and they are thick. So I took them home to see if they'd fit on the spindle.....and whaddaya know....perfect fit.....not even a little play. I screwed on my chuck and now the wobble is gone.

Just thought I'd share this little discovery. Old hard drives have very little use....And with the increase in technology....they are everywhere.

Oh....and the magnets are super strong and useful for tons of things.

[David Fried]

Now you tell me!! I just took two to the dump yesterday! I had disassembled these so the kids could see the platters and other internals. Maybe they will still be there next week.

[Ken Fitzgerald]

Nice recycling job John!

I recycled some of those little rare earth magnets too! I was doing an installation on an MR scanner and had another one to do. The 2nd MR scanner was a 3.0 Tesla magnet. I had a piece of steel embedded in my arm since I was age 15 working on oil rigs for my Dad. I knew from experience when I worked up inside the 1.5 Tesla magnets I could feel the steel twist in my arm. I was really concerned it would be a serious problem when working around a 3.0 Tesla MR magnet. So I called my personal physician to get the steel surgically removed.

I had recently installed a cat5 hub on the MR scanner I was working on and there were some spare small rare earth magnets used to mount the hub to the top of the computer chassis. Just before leaving the hospital to walk across the street to my doctor's appointment, I picked up one of the spare rare earth magnets and placed it over the piece of steel that had been in my arm for 40 years. Yup......It caused the piece of steel to pull out ........looked like I was pulling on some hair on my arm. You could see the steel through the skin because of the steel's painted blue color. I took the rare earth magnet (circular about 3/8" diameter and 1/8" thick) with me to the doctor's office. His nurse placed me an examination room and said we'd probably have to have an x-ray to localize the piece of steel before the doctor could remove it.....I said I didn't think that was necessary and reproduced my science experiment. She was astounded and got the doctor who was so impressed he asked if I minded if his staff saw it. 15 minutes later I was out the door without an x-ray and with the sliver of blue steel out of my arm after 40 years.:D

[joe greiner]

Ken: I hope the doc gave you a discount on his fee to recognize your contribution to the effort.

Joe

[Don Orr]

I would have been very concerned about that fragment of steel in a 3T magnet. I've seen things pull on peoples skin at work. Things like BB's are VERY magnetic!

Glad to hear it came out easily.