Has anyone found a heat conducting material that also lubricates for the threads between the head and cylinder? It could get a bit more heat out of the hot part.
I thought of heat sink transfer goo. But nothing that says it won’t dry out or turn liquid. Drying out could be a bad thing. Liquid metal bad on the not drying out side.
Copper Grease/Copper Ease/Copper Slip would have good thermal conduction I would expect, not sure of its viscosity at high temperatures but its commonly used on the back of brake pads to dampen vibration and does not seem to melt and run out, so expect it to be OK at Q8 head temps?
Try to get the best possible springs for the spare tail mcpcb, to let us get extra 1000 lm. And maybe a kit with 4 brass screws.
And a tail cover with lanyard holes ;) TF might make double on these if they play it right.
I think all the same arguments that applied to the pages of electrical grease discussion pretty much apply to thermal grease but even more (more because for thin layers thermal connection is affected far less than electrical), and the conclusion then was, just get a good thin grease.
If we are looking for an aftermarket tail cover, I’d like to see one with enough room inside for a charging board. I’m fine with taking the tail cover off to plug in a USB cable. Some minor mods to the tail PCB and a TP4056 board and we would be well on our way to onboard charging.
Better make a tail cover that supports magnetic charging instead, that would make charging much easier since there will be no need to unscrew the cover to plug it in.
My first thought was that this is a genius idea. Around the house and even in the car it would be a quick way to charge it up and would definitely be quicker and cause less wear. My second thought was that battery banks have USB, but not inductive ports. Which means that you would need to carry a wireless charger as well if you were taking this camping for instance. My third thought is that the obvious answer to this is a product that I have not seen - a USB battery pack with a built in inductive charge pad.
Which I think has now become my next project.
Qi charge pad (currently out of stock).
USB Power bank
switch, batteries and a housing…
[edit]annnnd like most of my ‘brilliant’ ideas someone else has already had it, done it, and posted a video on how to do it. Still going to work on it.[/edit]
I apologize… The thread is long, my memory poor…
I impulsively purchased 8 30Q batteries on eBay… Didn’t pay attention, and they are flat top……I was a bit mad at myself, but this morning I popped them in…and the light worked ,ramped right up to Max output…
But is there something I should worry about, am I forgetting something . The battery discussion was so long ago….
Thanks
Tony
There is a possibility that the wrap may get torn while screwing the tube on. It is also not certain that all four batteries are making contact. which means that your run time will suffer and your cells would get mismatched. Do you solder? IIRC test results indicate that the best performance is from flat top cells that have been modified with a solder boob - a small mound of solder on the positive terminal. A quick search of BLF for either “solder boob” or “solder blob” should get plenty of how to’s.
[edit] I just found a nice vid thread Barkuti did using ‘Roses metal’, but the technique is the same regardless.[/edit]
If you can, you should put a drop of solder on the top of each of them. They’ll make better contact that way. As it is, you have no way of knowing whether ALL of the cells are contacting completely all the time. You might end up with unbalanced cells.
EDIT: Lazy-R-us beat me to it! 
Thanks for clearing up my memory. I’ll blob them then. Not worth the hassle of returning
You will need a front cover instead of the head to charge the battery. So an option would be a talcap with lanyard hole and a removable front cap with charging-Circuit.
Otherwise you wont get contact to the battery+ side.
There is no denying that it would be simpler to do on the front side, but there is quite a lot of room right down the middle of the tube for a spring loaded connection to the positive end. Enough room that I have printed my Joechina cheat sheet larger than he intended (75mm IIRC) and rolled it up to store in that space.
Having said that, it is an interesting thought that you could have a spare battery tube with tail PCB and cap, loaded with batteries and on charge. When it is time to load a fully charged set of cells, you unscrew the head and this ‘charge cap’ then simply swap them.
I think most of those are designed to dry out. They’re meant to be very liquid when you apply them so they spread everywhere evenly. Then they dry for slightly increased performance. At least that’s what I remember reading a long time ago, back when CPU cooling was more critical.
Thanks for the reminder. Some of the marketing seems a bit less than accurate, so I put up a comment to give a bit more info about it. Kind of disorganized, but hopefully it’ll help.
Marked TK’s comment at Amazon as helpful. Definitely.
(Do we even know the light is anodized, rather than painted?)
$128.99 and FREE shipping! 
It claims to be in stock, just one. But it may arrive after Christmas. :person_facepalming: