Flattning a P60 pill

Flashlight Modding and DIY Parts
1

When I started doing p60s, I thought I could sand the very uneven platform flat…doesn’t really work. I’ve tried steel wool on a metal rod in a drill press…no good. I have finally devised a way to flatten the platform reasonably well.

But first, how un-flat is it? I’ve checked several pills with the following method: I used a Noctigon and lapped it perfectly flat. Then I pressed it into an ink pad (the kind for rubber stamps). Using tweezers, I carefully placed the MCPCB into the pill and pressed down on the center with the tweezers. Then I lifted out the MCPCB and looked for the amount and placement of the ink in the pill.

What I saw was -

  1. the platform was almost always higher and thicker in the center
  2. the platform was never flat
  3. typical ink contact (metal to metal contact) was typically around 20%

You can also place a lapped star in the pill and press the edges with tweezers and see if it rocks…if it’s higher in the middle, it will.

I bought a pair of 16mm hardened steel pins (about an inch long). Steel pins have a radius on the ends to make insertion easier, so I ground it off, then squared and polished the ends. Then I put the two pins into the pill and pressed them with a 4 ton press…it helped a little but not enough.

Next, I put the pins in the pill and hit the assembly with a hammer a few times…much better results, but not perfect.
(Remember, the center is usually the high point and thicker, so when I hammer it, where does the metal go? It is soft, but not soft enough to squeeze out from under my 2 pins)

Next, I cut shallow groves in the end of one pin, this pin is always placed on the driver side. Now, when I hammer it, if there is excess thickness, it squeezes into the grooves on the bottom pin.

Now, I did the ink test again and I’m getting typically 80-90% contact…I can live with that.

So here are pictures of my flattening setup.

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It’s a little bit of an optical illusion, but the star you see in the pill in the last photo is raised, not depressed.
If you do very many, you should invest in a set of these…if you make a set or have a set made for you…make them shorter…mine are too long (1”), they’re a little less stable when hitting them with a hammer, but they are long enough to hand hold.

2

interesting. most people remove metal to make it flat where you are just reshaping it. I like it.

you might have better luck with some wet-sanding paper (very fine grit) in the drill press to get that last 10%.

3

I hate to remove more metal (even a very small amount) on an already thin piece. I have never had much luck sanding…yes it makes it look better, but I can’t tell it’s much flatter.
The displaced metal (star looking thing on the driver side) is still a thermal path.
I’ve found, sanding in the drill press doesn’t work very well if I try to sand the entire platform at once. The speed of the sandpaper in the center has a very low speed -the very center is actually not sanding at all. I’ve tried using a 1/2” rod in the drill press with a 1/2” piece of psa paper and moved the pill around under it…it worked okay…but very time consuming.

4

Kudos for coming up with what looks like a reliable and quick method of flattening the mounting surface.

Double kudos for doing it without removing mass. I never liked sanding P60 pills. They’re already so thin to begin with.

5

Nice.

6

Bravo! Very cool idea and appears to be well executed too. I think you idea would work on aluminum pills too if one were to first anneal the emitter base landing first.

EDIT: Although annealing would make the aluminum softer and less likely to crack, I don’t think it is a viable option in most lights. The temp needed to anneal is near the melting point. So it would change the anodized finish color and would also soften threads and such.

7

http://steamshed.com/annealing%20process.html

different for each metal