Aaaaaalrighty then ... another weekend, another Diver mod update. This here is kinda how I modified the Diver (this time) to ditch the flange, enshorten the tube, and a new thingymabobber I did that might help with an issue I ran into over time.
Behold, the Diver, in all its original nakedness.
This is a good time to caliper the diameter of the tube itself as a benchmark for when you're done removing flange material.
And the Diver was ashamed, and did cover itself ... actually, this is just for protection.
A single layer of gaffers tape (kinda like duct tape but thick woven cloth, lower tack and removes clean).
Made sure there was no overlap so as to not to make it eccentric when chucked.
Protected Diver chucked into a drill press, moderate pressure. Don't want to over tighten and damage/crimp the tube, but don't want it to wobble or fall out. During the operations, drill press was set up for 3000 RPM.
After trying a few other things, this metal file did the best job of taking material off the flange while providing good control. With two hands it was easy enough to brace on the drill press table and make sure the file only contacted the flange.
This pic was NOT taken during the actual operation -- only so many hands, dontchaknow -- but shortly after starting I put some gaffers tape over the threads too, to make sure a slip of the file wouldn't ruin them.
During the operation, if the lighting is good you can easily see the flange sticking out. Keep filing material away JUST until you can't easily see the flange. Use the caliper to check. Only file away material until what used the be the flange area matches the diameter of the tube.
When done filing, while the Diver is still chucked bottom-down, now is a good time to do two more things:
1. Check the bottom edge of the base to see if it's sharp. If so, spin up and use the file to lightly radius or chamfer the edge.
2. Spin up and use very fine sanding/polishing paper until you're satisfied with the finish. It doesn't have to be glass-smooth but it should not be rough.
A dimple left in the gaffer's tape from the drill press chuck.
Proof that the gaffers tape did its job and protected the Diver tube.
Gaffers tape removed and re-applied to cover the BOTTOM of the Diver, leaving the top of the tube exposed -- 'cause we ain't done yet. Chuck that puppy again with the top facing down.
This kind of thing will probably get me kicked in serious machinist circles. After checking the drill press table as square as I could with a machinist/engineers square, I braced a grinding wheel to a billet of PTFE (checked level/square) on the table, pressed the chucked Diver on to the grinding wheel and zeroed out the digital depth scale on the drill press.
Knowing that about 1.9mm needs to be removed from the top, I spun her up, lowered to zero, and started adding pressure to remove material on the face of the grinding wheel. Periodically I'd move the wheel about to get a fresh cutting face. Stopped when the meter read 1.9mm.
After that, used a smaller/finer file to deburr the outside and inside of the Diver tube and hand-polished the end with some fiber optic polishing paper I have handy. Calipered to about 34.8mm with the Diver tube fully tightened down, providing play up to about 35.3mm with the tube not fully tight but still sealing on the o-ring on the base.
About the new issue: After replacing the silicon gasket in my Billet Box the draw on the Diver got REALLY tight with much flooding and poor vapor production. Thought that I'd really messed up my last re-coil, but it worked great when the same Diver/tank was tested on an eGo battery. Did some dry fitting without the tank and found this:
Basically, the replacement gasket seems thicker than the one before (which might have just been compressed over time, not sure yet). The new gasket was pushing up into to the air flow channel of the Diver base and cutting off air flow when the brass ring was snugged down.
To be fair, this probably would not have been a problem had I not shaved a bit off the bottom of the Diver's center pin to make it level with the thread collar (described in a previous post) ... but at the time I felt that was necessary to provide a good seal with the gasket, and did not realize that the Diver is not like a standard carto wiith an airflow hole or two drilled through the base above the 510 threads. The air channels are slotted into either side of the connector with shallow cuts in the bottom. The combined effect is to allow air down through the 510 threads (on a standard threaded mod) and under the thread collar to get to the brass positive pin (with channels cut into the bottom) and up through that into the body.
I think the fix is to make those shallow cuts a bit deeper with a rotary cutting wheel, so it ends up like this:
Just dry-fitted, that looks like it should allow for a bigger gap for air flow when the brass ring is snugged up, while still sealing everywhere else around the collar. This has not been tested yet, but I should get a chance to try this out with a tank tomorrow.
Assuming that is the last of the mods, a summary of all the mods I did to make the Diver more BB-friendly:
- Shorten the Diver upper tube so the total length is about 35mm;
- Shave off the flange so the diameter of the base does not exceed about 9.3mm;
- Shave just a bit off of bottom of the Diver's brass positive pin so it sits flush with the thread collar;
- Cut the air channel slots on the very bottom of the Diver base just a bit deeper so the BB's gasket doesn't block air flow.
How you do all that is up to you. But what I highly recommend, if you are really interested in this, is to lobby Atmistique to make a BB-specific version so you don't have to go through all this crap. Or, just wait for DD to finish designing a custom RBA module.
