58mm. Full specs on it’s components are in my review and pics here: UPDATE: 5/19!! Review: ULTRAFIRE HD2010 from Tmart (warning: lots of pics!!)
There might be just enough room in there to triple stack them… I didn’t take an actual measurement when I had mine apart. Theres definitely room for a 2x stack though. I dont think an insulator between the board and ring is a good idea though. I speculate that the ring also serves as the -B contact for the board.
Yeah, I wasn’t sure if the edge that the board sits on would be enough of a ground. I already have my 8 x 7135 board, so I’ll try to figure something out with that.
Back to the drawing board for me as well. I was really hoping the 8 chip driver could be screwed on.
Looks like Andi was able to solder the PCB edges straight to the pill or do my eyes deceive me?
No he used the brass ring piece from a C8 pill. Others have had success soldering directly onto Aluminum, I haven’t though. Its always been easier for me to solder onto copper or brass.
Just a side note… brass is a SUPER easy material to work with. Hand fabricating it is easier than Lexan-polycarbonate (which can be shatter & chip prone) and even some hard-woods which can have complex grain structures that complicate tool stroke motion and direction. Its on par with acetal (Delrin). Grinding tools and cutting wheels plow right through Brass with no tooling wear. I laugh at the boutique builders who tout Brass as an exotic, high-end option for their designs.
I would have taken build pics of my P60 pill cut-down mod… but I had no idea it was going to work as well as it did. So sorry about that.
Thanks JohnnyMac 58mm.
you’re right my t601 aluminium pill is almost impossible to get to stick…I have it soldered now, but it I disturb it too much (as in direct force by twisting) it lets go…this would never happen with the copper driver installs…glad it isn’t just me and it’s the aluminium lol
I also have one of these on the way plus the two purchased from Kaidomain. Hopefully I’ll be able to manage to get one of them to work correctly.
Aloha and welcome to BLF Inspector34!
Thanks for the warm welcome. I've been lurking for months...time to join the fun!
By the way, my 8x7135 is shipping soon. If anything interesting happens with the swap I'll be sure to share.
I used the C8 rings as well to convert the ones I have done also.
Hi, i bought one of these from easy light buy, i was wondering, when should i swap out the battery, does this start flashing at low voltage or should i use other magic to determine when to recharge as i have read i should not rely on the cell protection circuits.
It's good to have you here, Lord_Niksidor!
Good to see you here. Are you using a protected battery. What brand of flashlight did they ship you and how long did they take to ship to Australia? Thanks.
i’m using a “TrustFire - Protected TF 26650 3.7V 5000mAh Rechargeable Li-ion Battery” from manafont, i read the review by benkie, don’t have the torch yet, only been a week though, im just trying to make sure i don’t over discharge the battery first time will post shipping times when it arrives.
Aloha and welcome to BLF Lord_Niksidor!
Postage to aus was damn fast (somewhere between 10 and 20 days im not sure because i work away and havn’t been here for 10 days) I got shipped an ultrafire torch, finish is excellent, not a dent or scratch on it, and daym it’s bright, lights up the forest a good 500m away increadibme throw, mine came with a little rubber grommit that centers the reflector, which is handy, tail cap 4.63A on high, I couldn’t recommend elb any higher, I got the $2 tracking thing, not sure if it was worth ot but it is cool when you get updates, definately worth the wait…. Now off to blind some kangeroos, after my vision returns of corse.
Hi Lord, where did you buy it from that it came with a centering grommit? If you get a chance to take a photo of the part and post it, that would be great too. Glad you like your light. They really are excellent.
My modded HD2010 against other Lights…
Solarforce Masterpiece Pro-1
EagleTac M3C4
HD2010 (MOD)
“Green Thing” Selfbuild HID J) …not mine 
I replied in the "other" HD2010 thread, the Fandy-version, about a weird behaviour my light has with 26650:
If any of you have a clue how to make it work correctly, otherwise the driver swap will be the only possible way to use it with TF26650 (and get rid of the flashies alltogether, which is an appealing option alone... 
)
Andi what about your mods? You said you were making them for others (sell?)
Would you consider modding the pill with that 7135x10 for sale?
Germany to Italy is easier on postage too