Ah and yeah thanks for giving us a hard time making that tripod hole a part 
No joking, it is an awesome part, really thanks 
The diameter in the middle of the battery tube, away from the flat bits is 50.0 mm.
You’re very welcome! The Q8 will be an awesome work light when paired with a small tripod!
Thanks! :+1: Looks like a good fit for the truss clamp.
For anyone interested, the 2” quick release truss clamps can be found on eBay for about $10 each.
To make two mounts, go with a ‘dual swivel’ clamp like this:
I had one made for my bicycle to mount another BLF Special edition light. One of the Truss vendors on Ali Express made it on order.
The bolt on the truss clamp fits the tripod socket on the flashlight?
Hmm, I suppose you could configure it that way using a 1/4-20 (quarter twenty) bolt if you wanted to fasten the light to a 2” cylindrical object, but my plan was to hold the flashlight in the clamp and bolt the clamp to a bike, ATV, etc.
Sorry if I created some confusion by mentioning the tripod hole. I plan on using the tripod mount for using the Q8 as a work light, and using the truss clamp in more rugged situations.
Please add me to the list for one unit. Thank you.
Yes 50mm (or 1.968 inches
Oops m=mm
Did you mean 50 mm??
I was thinking about reflowing 4x Nichia 219C 4000K CRI 90+ D240 LEDs instead of the XP-Ls.
Does anyone have an estimate of roughly how many lumens I can expect to get with this setup?
My crude estimate places the output at around 4000 lumens.
There’s many parameters playing a role, but my guess would be a bit lower, say 3200 lumen.
How well will the flashlight tolerate 4.35V cells as opposed to just 4.2V cells? IS there any risk or harm in using 4.35V?
Yes, there is a risk of blowing the leds. This flashlight is completely direct-drive and with high drain 4.2V li-ion cells it runs the leds close to their maximum. Running them even harder with 4.35V cells might be too much. You may be saved by the 4.35V cells not being high drain enough too maintain their voltage, in that case there is no reason to use the high voltage cells anyway.
Thanks, Miller! :+1:
All the 4.35v cells I have tried so far had significantly worse performance then a high drain 4.2V cell. They have pretty high resistance in my experience.
This cell (samsung 30B) seems to handle 7amp pretty well though:
http://lygte-info.dk/review/batteries2012/Samsung%20ICR18650-30B%203000mAh%20(Green)%20UK.html
It maintains a higher voltage, even towards the ends of its discharge.
If you compare the 5A and 7A discharge curves with the 30Q:
You’ll notice that the 4.35V 30B does not perform as well as the 4.2V 30Q.
That 30B curve looks pretty good to me, not for max insane 30 sec output, but for low and steady... Appears to be a nice cell for FET DD normal usage.
Not saying that the 30B looks like a bad cell, just that the 30Q would be superior for maximum output, which I assume was the point of using a 4.35V cell.
Atrocious drop at turn on, would be losing a lot of light for a long time before seeing any positive out of it.
The potential for 4 of them in parallel to pop emitters at turn on would make it totally not worth the effort. In a single cell use, with the high Vf of say the Nichia 333 UV emitter, then yeah, it makes sense. (I actually do use this cell for just this purpose, a high Vf emitter at 3.8A that places a high demand on the cell.)