Hi..It was good to see your photos. I have been collecting old hard drives for a year or so..very hard to get as people are paranoid about data and privacy. However, I have about 50 or 60 intact magnets (as well as the 10 or 15 that got broke..no matter whose advice I followed). I also just picked up another dozen 20 to 80 Gb Fujitsu drives from a mate, so I'll be extracting the magnets from them tomorrow.
Its so bloody hard to get sets of matching magnets. Does anyone know how many I should have to start a reasonable project. If I am using my mill to..say, charge my mower battery and a few NiMH batteries, do the magnets all have to match?
The voice coils from the hard drives have me thinking as well..the great thing is that they are already very neatly, tightly wound, exactly to match the magnets. I ran the trusty old Fluke over a couple and got resistances of 30 or so Ohms. Is that too much? Can the fineness of the wire be overcome by using a lot of them in parallel?
Their perfect shape means that the airgap can be absolutely minimal. The hard drives also have great sets of bearings for small projects. I can imagine the bearing the arm carrying the heads pivots on being the basis of my tail pivot. Actually, it wouldn't be hard to use the whole arm.
The bearings in the actual disc drive mechanism must be awesome...if a bloke could only separate them from the drive motor. I have dissected and experimented with a few of those motors and they are a total mystery. Seems like a radial flux, permanent magnet motor with laminated cores in the coils, (like the "Smart Drive"..but tiny)...but there must be some tricky circuitry in there.
In the process of dissecting the hard drives, I also now have enough highly reflective discs to make a great heliostat. Heh, heh, if 120 or so suns focussed on a 95 millimeter diameter target won't run my still, there's something wrong!!! I have an old door that I figure I can hotmelt glue one edge of each disc to, and put a couple of screws through at 60 degrees round the diameter to focus each disc on the same spot..
I've also been scavenging microwaves ever since I discovered this forum...I now have 22 of those ferrite ring magnets..but only about 14 matching. There's a shirtload of copper wire in each one...fine stuff in the cooling fans, then a couple of heavier grades in the big transformers, and occasionally intermediate sizes in other transformers. I have had virtually no problem unwinding the transformers..even tho the wire has been sort of glued together, the windings seem to come apart ok without losing insulation. Just have to get onto the laminations with an angle grinder to separate them.
But..with my wife complaining about an ever-increasing collection of stuff in the garage, I need to start a project soon...any suggestions?
If anyone can tell me when I should stop collecting and start building, both my wife and I would be very happy.