putting together a Copper P60 Quad Dropin,do i still need to apply thermal paste,correct?
also any tips on how to glue down optics or dont glue?
4 xp-l hi v3 1b
carclo 10621
FET + 7135 Driver - 17mm - MTN-17DDm
For the MCPCB you need good thermal paste
If you are not planning to switch dropins some cheap thermal paste to the body will help fore sure
thank you,thermal paste ill be using is artic silver 5
Ermahgerd, ermahgerd, ermahgerd!
Yes, absolutely positively definitely 100percently YES.
A quad and FET driver will start cooking very fast, and D26 drop-ins are notoriously not that great as far as thermal path. So yeah, unless you want your LEDs to go incandescent, definitely go crazy with the thermal stuff.
Preferably go over the back of the board and the top of the pill with fine sandpaper to smooth out any imperfections. Sandpaper on a sheet of glass, scootch the board across that in small irregular circles, clean off with alcohol. Use something similarly flat for the pill to lap it around.
Thermal goop like AS5 under the hopefully DTP board. More is not better. It should just ever-so-slightly squish out from the edges after firmly compressed.
Wrap the pill around the threaded part with preferably Cu foil, or failing that Al foil, to make it a snug fit while gently twisting it in. This’ll at least make marginally better contact between pill and head.
Then, go crazy. Try to not cook the LEDs.
will a tail switch spring bypass help?or make any difference?
Yep, thermal paste is required. AS5 is fine, but If you haven’t ordered it already, there are better alternatives out there these days. Regardless of which TIM you use, it’s only effective when used correctly. So, try and ensure the mating surfaces are as flat as possible, with no major pits and/or deep machine marks (sanding/lapping flat if necessary), and use as high of a “clamping force” as reasonably possible. This is achieved by either tapping the P60 shell’s shelf, and screwing the MCPCB down (preferred), or by simple friction of the optic forcing the MCPCB down from the bezel being tightened. The issue with the latter is that the MCPCB can “spin” while the bezel is being tightened. Either way, the key is to use as little TIM as possible, while achieving even coverage and clamping force. I’ve seen many manufactures use waaaay to much TIM, which is counterproductive.
Also, I wouldn’t bother with any optic glue. I just don’t see the need, and it obviously makes things easier without it if/when you want to change optics.
Lastly, I wouldn’t use TIM on the exterior of the pill where it mates with the host either. It’s messy, and not effective for the typically larger air-gaps that are present in the pill-to-host fit.
Instead, I would simply wrap the pill with raw copper sheet (NOT adhesive-backed copper foil tape) until a very tight friction-fit is achieved. You want to use a thickness that is as thick as possible to reduce the number of wraps (air gaps), but still thin enough that it’s pliable and easy to work with. I’ve found that the 5 mil stuff you can buy at most hobby/craft stores works well. If you don’t want to bother with copper-wrapping the pill, you can use aluminum foil. It won’t be as effective/efficient in conducting heat, but it’s better than nothing, and also better than using copper/aluminum tape.
Have fund and post pics of the finished product! 
i will definitely post picture once im done,regarding switch bypass,do you recommend it?will it make a difference
Bypassing the springs will help if using cheap springs (pretty much a given), and will let more current through the LEDs, especially if DDing them or FETing them. Which makes a good thermal path that much more critical.
It’ll also keep the springs from overheating (turning into heating coils: great in a toaster, not so much in a flashlight) and crumbling away.
To me, high current and drop-ins don’t go together. Don’t get me wrong, my EDC is a ’502B and I love the L2M, but I don’t push those LEDs very hard. (I like decent runtime.)