I am posting this here because I have had posts "disappear" or get censored in the vendor's forum. I know there are other people out there who have had the same problems I did with my ACTv4 tanks fitting on my various mods/batts with 510 and eGo connectors, because I have been in contact with others and seen many other posts about it around the 'net.
Note, I got my ACTv4 tanks in February. As far as I know, I was the 2nd person in the US to get them. I don't know if the tank body itself is still made to the same dimensional specs as it was originally (although I suspect it is). But I DO know what the real problem with the tank fitting using the included shorty adapter was.
It most definitely was NOT a "dodgy connector" on my mod. I mostly believed that at first (what I was told) until I figured out what was really going on. First clue: Everything else 510 or eGo fits and works FINE on my mods. Second clue: Same fit problems when I got my Provari's. Sorry, but I'm not buying that the 510 connector on my Provari's (and those of my co-workers) are "made wrong" when your tank/shorty combo is the only 510 attachment I've seen yet that won't fit right on them.
You can go on and on about thread diameters, tolerances, and any other kind of "wookie defense" that you can dream up. But the real reason for wobbly ACTv4 tank fit, crushed center pin, etc. on my mods using the provided shorty adapter is extremely simple:
The "center pin solution" of the included shorty is just too @#$@#$ long. You can blame it on people's mods, "dodgy connectors", etc. but you are lying to them.
Yes, with the ACTv4 design, you have to compensate for the length of 510 battery threads at the bottom of the cartomizer that gets "lost" by the thickness of the metal at the hole at the bottom of the tank body. But not OVER-compensate. The thickness of that metal there roughly equals the amount of carto battery connector thread engagement and center pin length that is effectively lost. This is why there is basically NO standard 510 shorty out there that will work with this tank. You won't get any center pin contact unless the shorty is specifically made with an "over length" center pin. But not SO over length that you can't fully turn everything down without violating laws of physical matter (2 solid objects cannot occupy the same space).
So what about the $7 Mad Vapes shorty connector? Why did that one work?
I have sat on this information for a number of reasons for months. Primarily, because I did not feel it was MY job to fix Arry's design problem for him, and I did not appreciate the $ and hassle I went through trying to solve "my" problem because somebody couldn't admit it was a design mistake and sent me on a wild goose chase of buying/trying other 510 shorties instead.
However, since Mad Vapes has taken this shorty off of their site now (it has been out of stock for months), and NONE of the others out there that "look like it" (don't be fooled by others that come with a nut) have the matching single critical dimension that matters - I'll share what the answer is. Maybe somebody that cares and has the means can get some made that properly accomodate the special center pin needs of this tank.
The answer is the center pin length. The center pin from the $7 Mad Vapes connector center pin measures .303" long on my dial calipers. This is longer than the center pin on most 510 shorties with a floating center pin design. For example, the center pin on m0bius' sealed 510 modders shorty (which works fine with every other 510 attachment/tank/carto I tried, just not Arry's v4) measures .288" long.
The .015" extra center pin length allows the $7 Mad Vapes 510 shorty -- and even other shorties I tried which didn't work but that I could fit the Mad Vapes center pin into -- to work PERFECTLY with the ACTv4. No wobbles, no fit gaps because you can't turn the tank all the way down before the center pin bottoms out in the mod connector, no leaning ACTv4 tank, etc. No crushing the center pin in your mod or shorting it out trying to get the tank tightly enough onto the mod that it doesn't flop around like a bad knuckle. No worrying about whether you have to screw the shorty onto the tank or into your mod first (after all, if the (floating...) center pin is the right length for the tank then IT DOESNT MATTER). No tank falling off the shorty and damaging threads because there isn't enough thread engagement to hold it properly and you lean over with your mod in your pocket. And it fires properly.
You don't need an adjustable shorty. All you need is a shorty with center pin that is the right length for this tank design. And an honest designer.
It really is that simple, folks. Somebody across the pond knows this too... But I suppose it's easier to SELL people the solution to your design and QA problems if you're not going to do the right thing - which is to admit you made a mistake and replace the defective equipment on YOUR nickel - if you can convince everyone the problem is something else. And try to maintain strict control over what gets said about your products in public so the supply of unsuspecting buyers isn't disrupted.
I doubt I'll post any followup replies to this thread. I'm just sharing the info. I hope for the sake of others buying v4's that the problem no longer exists, but for the folks who already bought one or more... or doesn't like the adjustable shorty (or doesn't feel like they should have to BUY one because the v4 they bought came with a bad shorty), this info will most likely help you.