I think i've finally solved the problem of piston requiring too much pressure to activate on my (well, probably any) Arc6. It's not so much a problem of pressing the plunger and keeping the required pressure, as the tritium slot leaving a mark on my finger and me starting to get blisters from it 
I've had this pack of VCR spare parts lying around, that i've bought because of all the assorted washers it contained. They come in real handy for RC heli's.
Anyways, after trying out nearly everything i could with the stock spring (and breaking one in the process, along with a few replacements i've tried to modify), i've remembered yesterday there are some springs in that bunch of parts and took a look - and, voila! I've found a good PD spring! The base is just a tad too wide (maybe half a mm) and the helix isn't conical, so it doesn't compress all the way. Reshaping it isn't much of a problem, though, because there's only about three and a half winds.
The original site seems to be down at the moment, but you can find a description and a photo here (second to last article, at the bottom of the page):
http://www.siliconchip.com.au/cms/A_102842/article.html
After installing that and replacing grease with some fine mechanics oil, it's now butter smooth and requires just the right amount of pressure to activate! I'm using a mix of synthetic oil and a tad of silicone grease on the head and that has proven as a really smooth combo too.
The oil's pretty cheap, off-the-shelf stuff, but i've already tried it on a few lights (including Nitecore's SmartPD) and it works really well:
http://www.nigrin.de/nc/produkte-7/produktsortiment-149/produktdetails-151/article/nigrin-feinmechanik-oel.html?tx_ttnews[backPid]=158
I've had this pack of VCR spare parts lying around, that i've bought because of all the assorted washers it contained. They come in real handy for RC heli's.
Anyways, after trying out nearly everything i could with the stock spring (and breaking one in the process, along with a few replacements i've tried to modify), i've remembered yesterday there are some springs in that bunch of parts and took a look - and, voila! I've found a good PD spring! The base is just a tad too wide (maybe half a mm) and the helix isn't conical, so it doesn't compress all the way. Reshaping it isn't much of a problem, though, because there's only about three and a half winds.
The original site seems to be down at the moment, but you can find a description and a photo here (second to last article, at the bottom of the page):
http://www.siliconchip.com.au/cms/A_102842/article.html
After installing that and replacing grease with some fine mechanics oil, it's now butter smooth and requires just the right amount of pressure to activate! I'm using a mix of synthetic oil and a tad of silicone grease on the head and that has proven as a really smooth combo too.
The oil's pretty cheap, off-the-shelf stuff, but i've already tried it on a few lights (including Nitecore's SmartPD) and it works really well:
http://www.nigrin.de/nc/produkte-7/produktsortiment-149/produktdetails-151/article/nigrin-feinmechanik-oel.html?tx_ttnews[backPid]=158
, I use a similar solution. NyoGel 759G and a drop or two of sewing machine oil 
