I did a bunch of playing around with the magnets I have and my L0D-CE (a non-Q4 model, a bit more than a year old). The magnets that I used were a
D41 magnet (1/4" x 1/16", 3.67 lb pull force, nickel plated) and a
D42E magnet (1/4" x 1/8", 3.75 lb pull force, epoxy coated).
The magnets are pulled into the tail recess of the L0D-CE. The item they are attracted to is the spring inside the light. The battery is held far enough from the bottom of the light that I do not think it interacts with the magnet. I took the battery out, and saw that I could get the spring to wiggle by moving the magnet. Then I put the light back together, and it didn't work. :eek: I must have manipulated the spring into a non-contacting position. I fixed it by pressing down on the battery with my finger as far as I could, which seems to have re-seated the spring, since the light now works. :sweat:
While a magnet will sit in the tail recess of the L0D-CE, it has much greater affinity for the steel pocket clip. So I took a series of photos with the D41 supporting the light, showing that it has plenty of strength for basic attachment applications.
Ouch, that door is dirty.
When I removed the L0D-CE from the switch plate, the magnet came off the clip and stayed on the plate, I had to pull the magnet off by hand, not easy to do with a thin, strong magnet.
Here you see the D41 magnet sitting in the tail recess of the L0D-CE.
The D42E magnet is the same diameter as the D41, but it is twice as thick. The pull force isn't much higher, but it certainly feels like a much stronger magnet. I'll guess that the greater thickness leads to a larger magnetic field, so it has greater effect at a distance, but once it is flush to a ferrous surface the total pull isn't much higher. It fits very nicely in the tail recess of the L0D-CE and stays in better.
Edit: I should have payed attention to the magnet specs, they do specify the surface field, 2580 Gauss for the D41, 3750 Gauss for the D42E, that quantifies the strength difference that I feel.
The D42E sitting on the desk next to the L0D-CE
The D42E in the tail recess.
The D42E sits flush and does not protrude from the tail of the light. (Remember this is an old L0D-CE, a new LD01 may be different.)
The D42E will hold the L0D-CE perpendicular to a switch plate.
The black epoxy matches the black anodizing quite well, if I decide to glue in a magnet, I will probably use this one. K&J Magnetics only puts the black epoxy on a limited number of magnets, from what I see on the list the D42E is the only would that would fit an L0D or LD10, the others are too large in diameter.
For the LD01 SS, obviously the nickle plated magnets would match the finish best.
I did find out that the D42E is strong enough to hold up an old L2T.
I hope these examples prove beneficial to people. It does show that a smaller magnet does have plenty of strength to hold up an L0D/LD10. Might you want something stronger? That's up to personal preference. What fits best/looks best? Again, take your own pick.
Sgt. LED, you were trying to choose between two thicknesses, I'll give the typical CPF response: buy both, try them, see what works best for you. Since the magnets don't cost much, you might as well experiment.
On the concept of "how strong a magnet is too strong?", I don't know the answer to that. I'll ask a counter question: how stong is the epoxy you plan to use? And, how hard to you want to pull to get the light loose? And, what pocket do you carry it in, and what other items might it attach itself to?
Happy experimenting.
EssLight
