… and I drilled a hole in the center where a thick wire goes to the other side where the spring bypasses meet.
Strange why didnt you simple used the hole on the spring pad to wire the bypasses?
Usually I wire bypasses inside the springs but with double springs it seemed too narrow and fiddly. Maybe next time.
When I do this sort of thing I like to remove all of the original solder, e.g. using solder wick.
After a few scandals about toxic Chinese exports, you can be pretty sure that lead-free solder will have been used, some is excellent when used under tight process control, but most is not.
Thankfully, good old tin-lead solder and paste is still available, I use nothing else, it’s like night and day. when DIYing, but when mixed with the original solder it is never quite as good.
Nice mod, by the way.
Wow! I’m going to have to learn how to solder. :scared: 
Whew.
I wish someone would start selling aftermarket performance modification parts like that.
Make new tail PCBs with those beryllium copper magic springs.
And bus bars instead of wires and traces.
Acrually I designed a Q8 2S/2P tail board, not hard to make one for 1S/4P, but modding the original is easier
Steel springs are fine when a lead bridges them, its easy with boards that have a vias in the center of the spring
I think DB Custom half jokingly suggested replacing the whole thing by a copper plate. You’d loose the loop for the clamp meter but you’d remove PCB resistance and improve contact to the battery tube. And it would be all shiny 
> replacing the whole thing by a copper plate
Anyone got a source of beryllium copper disks?
Hmmm, I wonder, do I still have any silver dollars anywhere?
(silver oxide is electrically conductive, so time and corrosion don’t reduce its usefulness
Copper plate, brass screws, and beryllium springs and holes for wire bypass’s(up to 18awg. if needed) of regular springs. 
Copper plate with integral springs, example TM36 battery tube.
Thanks Kawi, don’t know why they thought I was joking… pretty well known I’m almost as much a Cu fanatic as I am a TiFreak! 
:+1:
Has anyone bypassed double springs?
Looks like you have to unsolder springs, 20 awg silicon won’t feed thru top. Or do you drill big hole in bottom to feed wire up thru?
I run the bypass wire from the outside.
Thanks, duh, didn’t think about that.
First thing I'm going to do to mine (after taking it apart and putting it mostly back together of course) is flash bistro-HD on it and see how it handles the e-switch. Of course I've got to think about building that buck. It's not that it costs too much. It's that other things I want right now cost too much.
I just got done working on my Q8 for now. I bypassed the 4 springs with 22 AWG Silicone Wire. I stripped a few mm off each side, pushed it through the top of both springs, then carefully threaded one end into the via at the center bottom of the spring. Once I got them all in I soldered the bottoms then did the end of the springs. While I was at it I sanded where the tail pcb contacts the battery tube to make sure no glue remains. I also laid the 80 grit on a piece of glass then sanded the battery tube end that contacts the driver. Then I hit it with some 240 grit or something around there to smoothen it up, I’m not sure what kind of finish I ideally want on the tube face, but it feels better than it did stock. I have not done any amp or lumen readings, but my Q8 runs SIGNIFICANTLY warmer. Before I ran it for 2 cycles of 3min turbo and it was around body temperature. Now at the end of the first 3min turbo stepdown it is hot enough to burn myself. The temp reading flashed 5 times for 50C?
What dimension do the tail PCB screws have? They are very soft, will get them out, but not in again, they need to be replaced.
I also just bypassed the springs. I used 20awg turnigy silicon, but routed them on the outside of the springs (thanks Kawiboy1428). Spring and wire flex is good. Ceiling bounce before 480 lux, after 593 lux. Approx 20% increase.
It’s been mentioned that they are M2.5