Charger was ready, output on 30Q’s is 6200 lumen now.
How hard would it be for them to move the driver board back, either by shimming or not machining as deep?
Option #1. If we swapped these taller springs in, the longest protected cell that would fit would be 70.2mm. Would that be acceptable?
Extending the battery tube 2mm would allow for 72.2mm protected cells (plenty) and still compress the shortest cells an extra 2.5mm compared to the existing springs. This seems acceptable.
Option #2. Is to keep the flashlight as is and make the short cells longer. You could solder blob the bottom side (I’m not sure this is safe since it’s closer to the chemicals inside the cell) or use some type of spacer. A magnet like TK suggested (Thorfire selling the light with 4 magnets included?) or a simple penny dropped down onto the top of the spring.
Since we are still designing the light, the smartest solution is to make the light fit all cell sizes.
Option #3. What is the longest protected cell length? If it is less than the 71.7mm we have now, lets say it’s 70.5, then Thorfire could shorten the battery tube 1.5-1.7mm and it would still fit, barely, and the shorter unprotected cells would get an extra 1.5-1.7mm of spring compression. This depends on the longest protected cell length, though.
My vote would be Option #1
(with Option #3 being a close second, assuming it’s feasible)
Option #4. Thorfire could shorten the battery tube slightly then issue a statement saying the longest protected cells that will fit is xx.xmm. This might rule out certain really long protected cells, but would be cheap for them to implement (no buying of longer springs and wasting the current springs)
Jos, maybe you could get the local company to do a new run on those springs? Thorfire could use about 5,000 of em and I could use about 300. 
Maybe you could run a group buy and account for 10,000 springs… just a thought. 
The tube contacting with driver either way. If you move the driver the tube will move with it. The only thing changing that way is that the tube does not thread all the way in the head.
+1,000,000 
The majority of protected GAs should be less than 70mm.
If we wanted to make 70mm the max battery legnth, Thorfire could reduce the battery tube legnth 1.7mm and we would gain 1.7mm more spring compression on the shorter batteries.
This seems like a good solution.
(I highlighted Thorfire because they would have to do the shortening and any other tweaks to make the shorter battery tube continue to work)
Solder a wire from top of small spring to top of larger spring and have wire gauged for fuse strength
What about a thicker battery contact ring on the driver? While I like that for several reasons as a machinist, as a flashlight guy I like that anyone can easily shorten it for longer cells.
Maybe an owner could do that, but not Thorfire.
Once you cut down the contact ring for longer cells you can’t go back to shorter cells. So is that really better than having Thorfire shorten the battery tube length or have them use longer springs combined with a longer battery tube?
Besides, the average person would not be able to cut down the contact ring anyway.
Seems odd in the long run that every product out there strives to appeal to every individual, with all their individual needs. That isn’t the way to obtain optimum results. It isn’t possible to appeal to everyone, just the way things are.
A great many people have already purchased Samsung 30Q cells. Optimize the light to fit those cells and let those that chose a different cell adapt accordingly.
How many springs do I have left now djozz? You know I’m gonna send you the bill. 
I suggest the organizers of this project decide what is the range of cell length recommended for this light and be done with it.
To cater to 66mm up to 71mm protecteds is a rather tall order.
Perhaps 66mm to 69mm max?
There is no need to choose either or.
With a little adjustment in design phase, you can fit all cell legnths. Just look at my Option #1. (taller springs, slightly longer battery tube)
Nope, you are not the only one djozz. I totally agree with you. Changing the length of the spring/springs makes complete sense… to me anyway. It makes more sense than changing tube length at this point as far as I can tell. A longer spring beefier spring can be installed from the get go just as easily as a shorter spring.
My .o2… ymmv. 
Switching to a taller spring would still require extending the battery tube slightly to compensate for the taller compressed height that a taller spring brings with it.
When you pay for a very expensive Corvette, you assume the task of matching tires to the optimum performance capability of the car. You can’t cheap out on tires anymore. And so it goes. Either/Or was decided by the engineers that gave it the horsepower to spin fat expensive tires. If you don’t want to be forced to buy $2000 a set Michelin’s, don’t buy the high horsepower car to begin with. (My friends modified Camaro RR spun top of the line Michelin’s at 500HP, I’m talking about fishtailing at 65mph on the highway with a bit too much pedal… same car now makes 675HP, there’s not a tire out there that’s street legal that will hold this car on the road. $2000 a set or no.)
This light is like that Corvette (or Camaro RR+), designed to have the horsepower to put optimum light out the front. As such, not just any cell fills the bill. Since so many here have already plunged in well in advance of the receipt of this light and bought Samsung 30Q’s, it would seem the masses have already spoken in their cell choice.
Thorfire has a lot of experience building lights. They know the issue, why not let them come up with the most feasible answer to them and maintain price point, run with it? Not sure if anyone here knows what type of investments Thorfire already has here, whether or not they have 10,000 springs (doubles, so twice as many) in stock already or just what kind of lead they’ve taken. I personally don’t see any issue with the sample lights as shipped. I mean, why would someone run a 20A light on one cell when it takes 4? Back to the car analogy, who unplugs 6 of the sparkplugs on a Corvette’s engine and tries to drive it? Run the proper 4 cells and there’s not an issue with how it’s being presented.
BT 30Qs. Works for me