All,
I wanted to share my Seagate hard drive experience with all who are interested in salvaging some very strong magnets.
I obtained several old full height segate harddrives (SCSI) type with a manufacturing date of 1987.
The housing was very large and required the use of some very tiny star driver bits, but luckily I had a drill bit that appeared to be just the right size.
Once the rear of the unit was removed... I was amazed to find what appeared to be two curved 2" + nickle plated magnets.
After much digging, bending, hammering, etc. I got the rear of the unit off with the aid of a 5lb. sledge.
The mags are glued into place and I followed the recommendation of boiling water. This worked, but handling the beast afterwards proved a bit difficult.
The end result of removing the mags consisted of using alen wrenches to place down inside the holding mechanism and using a pair of channel locks like a vice. If you stacked multuple alen wrenches on top of eachother you could obtain enough distance to push the mag out so it could be grabbed.
Once the mages poked out a bit... A 6" C clamp was attached to the mount and one person held the clamp while I pulled with a pair of channel locks (used rag cushion to protect mags).
It required at least 50lb of pull to get these things out.
Once out... The fun began!
Don't get mags closer than 6 inches!!! They will slam together with great force and despite the warnings in the group... My silly but wound up with a great respect for magnets of this strength via a blood blister.
One mag attached to a ruler with string and placed on our mantel could be slighlty moved from 17' away with the other magnet!!! Movement was slight, but it was there!
Some of the magnets in the other 8 harddrives appeared to be epoxy coated (black) VS that of nickle... But the strength was the same.
I am not sure if I can use these curved mags for the Volvo mill project (because of their curve)... But they are great for experiments.
Summary:
If you have not had a chance to rip apart an old hardrive... DO IT! It's way better than a cracker jack prize and I estimate those 8 free drives saved me about $160.00 in mags. Found harddrives on a local recycling group called www.freecycle.org.
Also... Has anyone attempted to use the bearings out of these old drivers for a vertical axis mill? If so, what type of results did you see with respect to weather, resistance, etc?