The ones I grabbed look kinda like brake-pads.
Yep that’s exactly what they look like
Here are a couple. Often the holder has bends in it and makes it less handy to play with.
You can pry the magnets off the plates, but the magnets are way brittle and I often end up breaking one when doing this.
If you want a really strong magnet to play with, seek out an old 5.25” floppy drive - one of the early ones. They have a circular magnet that was used in the motor. So strong, it’s difficult to remove one from a fridge without divine intervention.
I’ve used the HD magnets to make clasps for woodworking projects. Good for holding “stuff” in place when a third hand is needed.
All the Best,
Jeff
Scallywag, I’ve also been collecting HD platters. I started when clients needed a data wipe on a drive that wouldn’t spin. Pulled the platters rather than smashing or drilling.
Not sure why I started putting the platters in a drawer after hitting then with the degausser, but there I go again collection “stuff”.
Some of the platters are more silver colored. They make great first surface mirrors as they are VERY flat.
For some reason I also stared stacking old CD disks from software releases Etc. Stuck a dowel in a hunk of wood and started piling them up. About 3’ tall by now.
For those interested in harvesting HD magnets, you will need a few smaller Torx drive screwdrivers. Be sure to look under labels for hidden fasteners.
Good quality stainless steel screws and aluminum (from the chassis) for recycling if you are so inclined.
All the Best,
Jeff
Yup. I have one of the $25 iFixit miniature screwdriver sets (well, it was $25 when I bought it, $35 here ) and it’s all I need for the screws. Some of the labels/stickers are a bit tough on just fingernails, so I’d recommend some kind of metallic spudger tool for those. As mentioned the magnets are quite strong so have fun with ferrous-metal tools occasionally snapping over to the magnets :+1:
The best platter I almost had showed significant head-crash damage. Along the inner half-inch the coating was mostly completely removed (some rings here and there remained). However, that platter technically belonged to an old employer and had to go to their secure data destruction procedures… (they drilled holes in the platters). My plan for my shiny platters is to mount them all in a frame as a cute artsy “mirror”.
That’s cool re: 5.25” floppy drives. I’m not old enough to have ever used one myself, though I’ve encountered them (and the actual floppy floppy disks) as scrap occasionally over the years.
salvaging magnets from old tech was something we did for several years.
now, we check out the recyclers on Craig’s List when we need some more.
regarding mirror-like platters: we used the hole as an aiming device
for signaling in Cub/Boy Scouts. it was harder to do as opposed to
using a dedicated signal mirror, but it can and was done.
fragility forbid inclusion in our load-outs.
Forgive my ignorance, it can be harm to the eyes look direct a Led driven by about 5 mA but with PWM?
the driver is AMC 4*7135.
A friend ask me if there will be eyes issues with PWM.
PWM itself will not harm eyes. However, if it’s slow enough, it can be unpleasant to see. Even disorienting, I think.
If the driver is 4*7135 the current should be 1400mA, so it’s unlikely to be 5mA unless there are 280 of such LEDs in parallel. I guess you mean 5W.
I don’t think it makes any difference if the LED is PWM controlled or current controlled as far as looking at it is concerned.
Too bright is too bright no matter how you get there.
As Scallywag said, a too slow PWM coupled with a short duty cycle makes for a very unpleasant light to use in almost any circumstances.
Some lights have truly awful PWM running in the 100Hz to 300Hz range with 5% to 25% duty cycles.
One of these will cause eyestrain and headaches for me and many individuals. Yet some folks seem immune to truly awful PWM.
There are several threads about PWM that are buried in the general info category.
I made a video of the LT1 PWM charactistics and duty cycle here:
That might help explain the relation of PWM to brightness.
And another looking at PWM vs camera shutter speed.
All the Best,
Jeff
Scallywag, Here are a few of my platters. 2.5”, 3.5”, 5.25”, and Big’en out of an old IBM mainframe disk pack.
All the Best,
Jeff
The big one is amazing. I don’t even have any 5.25s, and I expect within a few years there won’t be any active spinners in the house anymore.
.
Thanks Jeff :+1:
I will check this out. Is there a way to improve the duty cycle time ?
.
CNCman,
PWM and the duty cycle is baked into the firmware.
So unless you can get hold of the code and flash the driver you are stuck with the OEM settings.
In another thread TK told me that the 5K PWM at the lowest levels was to provide enough ” on time” pulse to light the LED.
I (think) I can detect PWM into 3K realms if the conditions are right.
Total dark and spinning fan blades that I can vary the RPMs.
5K and up and I’m good.
All the Best,
Jeff
Is it possible to modify a Halogen light bulb spotlight to use a XHP 70.2 led. I am concerned the reflector is not designed correctly for a led.
A good friend uses a cheap Q beam on his early morning fishing trips in his Bay boat to navigate to open waters. I thought maybe it could be improved since he is disappointed in its output. I wanted to dig into it since my operating table is vacant. 
Yeah, most likely the reflector is not shaped correctly for an LED. Think about where the light is being emitted in each case - and therefore where the reflector’s focal point should be. For an LED, it’s almost exactly at the bottom of the parabola. For a halogen bulb, it’s going to be some distance inside the reflector.
I have seen several Surefire lights that include a clip that makes it go bezel up when stored in pocket. What are the practical uses for such a configuration?
I know for some small lights you can clip to your hat and use as a pseudo headlamp but what of larger lights?
Do lighted forward clicky switches exist?
The lighting element and the switch are two separate pieces. So yes, you can mix and match to create a lighted forward clicky switch. As far as whether you can buy a pre-made lighted clicky switch, I don’t know. They’re not very common on factory lights.
At the time I ordered, CSLMN1.23 C8+ was out of stock, so I ordered a CSLNM1.TG C8+ 12 mode to swap the .23 into but I just learned the forward voltage is less for the red Osram. I’m new at doing swaps and figuring out drivers so what driver should I use in place of the 12 mode driver I ordered? I want to probably order stateside because I have a certain time frame in mind for a project (4th of July…). So which driver can I use turbo or 100% for a good bit without frying the red?