JJCCR Loop Dryer, Blower Assembly

UPDATE 2024-03-10. I've decided I don't like this as much as I wanted to. Don't get me wrong, it works. Quite well (to dry the lungs). So I'm going to leave it published incase some of you do like to use it this way.. and I'll update the T piece insert to be a little more user friendly as well shorly (I'll need it for the next edition anyhow..) But I want drying the lungs to be even more convenient if possible. So on to the next attempt.

UPDATE (2023)-06-01. OK. under-volting the fan (at least to 5-6V..) doesn't give it quite enough jam. maybe if you plugged in an adjustable brick, and tuned it till it has the right airflow to noise ratio for your tolerance.

but it does work. the new inlet duct to the inhale lung works well. I'll add the STL shortly.

UPDATE 05-31. It's built. It was tested. It isn't perfect (Unless you like jet engines in your house).

The Good:

• the loop hoses and exhale counterlung dry nicely, with the airflow passing one side to other of both of those.
• the fan has lots of airflow.
• the fan can be underpowered to reduce the noise, and still have lots of airflow for this purpose. I tried a 5V adapter on the 12V fan and it was much quieter while still moving a decent amount of air.

The Not Good.

• I don't recommend PETG for this. It's better than PLA but still brittle enough to break easily when dropped even a bit. I will test print it in ABS and Nylon soon to see how they do. (I have not done this yet)
• That damn inhale side counterlung though... what a pain to dry...
• I will be updating the threaded cap for the fan insert, with a duct to guide the airflow right onto the inhale side bag. The fabric idea, while... an idea... I'm not sure is a great one. To be honest I didn't sew up the tube yet, so it may work fine but I want something less fiddly or likely to fall off into the bag.
• The fan, with the rated 12V source, is loud af. Like, seriously. Do not run a 12V supply for it.

UPDATED 05-20. TEST PRINT IS DONE..

• updated STLs to fix a few issues.
• lid snaps work better
• fitment around the blower exhaust cosmetically tuned.

UPDATED 05-16. Large fillets are nay good for FDM printing. Modified the housing to chamfers.

I STILL (yes still) don't recommend you build this yet. This is still un-tested as a whole thing. Its printed and looks and feels fine, but Ive not yet wired the fan up, and tested to see if it has the power to make this anything but a big waste of time.

Stay tuned.

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This is a blower assembly to dry / air out the counterlungs and loop of my JJ-CCR Closed Circuit Rebreather after post-dive cleaning.

I have designed this to be reasonably modular. The blower insert threads into a JJ-CCR bung (included in this thing), with my JJ-CCR T-Piece threaded cap (thing 5996966) so that this will thread right onto the inhale side counterlung just like the loop hose from the head normally does.

You like this idea but don't dive a JJ? Design, and print your own bung, with appropriate thread (email me for specs) to mate against the blower insert, and cap style of your own, and it can probably blow air into near anything you like.

I couple the loop with my golem gear replacement coupler (thing 6022070), and the air from this blower can then pass through the inhale side counterlung, through both sides of the loop (with shrimp sitting by itself on the shelf), and into the exhale lung, venting out the exhale side OPV.

This blower housing is built for the, "currently available on Amazon Canada, but who knows for how long", GDSTIME 120mm x 32mm 12V dual ball-bearing blower fan. If this becomes unavailable, this thing will likely become obsolete. email me if you're in a pinch.

You will need:

• The GDSTIME or equivalent blower, with equal mounting hole spacing and outlet size / placement.
• a DC barrel jack, panel mount for an 8mm hole
• a 12V DC power supply suitable to the blower.
• some simple soldering, and sewing skills.
• a few orings, elastic bands, what have you.
• M4x0.7 x10mm or 12mm screws.
• some light, but air-tight fabric, I used kite fabric, 20d or 40d waterproof ripstop nylon.
• the printed files from this thing, and things 6022070, and 5996966

To assemble:

• print all the STLs. This took ~a day of printing.
• sew a tube of the waterproof/windproof material, ~20cm long, 30mm in diameter
• solder the blower to the DC barrel jack
• install the DC barrel jack into the lower housing
• place the insert into the blower unit
• install the blower into the lower housing, aligning the slots on the blower insert with the cutout in the lower housing
• click the top cover in place, ensuring the duct aligns with the off-center blower intake hole

(That's the hard part done..)

• place a T-Piece threaded cap Right Hand thread from thing 5996966 over the threaded end of the blower insert. Thread side out. I hope that was obvious.
• thread the JJ bung from this thing onto the blower insert. Doing so will also capture the T piece cap in place. You can glue this if you like to make it permanent.
• place the tube of fabric over the hose barb on the underside of the bung, and put a few 28mm orings, or backup light harness elastics / aka: cut up pieces of inner tube over the barb to hold your fabric tube in place. double it over to be sure it's tight if you need to. Maybe I'll make a printable insert to snap over this later.. we'll see.

It's built.

To use it, just thread it onto the top of the inhale side T Piece, feeding the tube of fabric into the lung as you install it - this tube ensures the air actually blows into the body of the inhale side lung before going out the other side of the T Piece. Without this, the air will just flow straight through the T Piece into the loop and exhale side, without circulating in the inhale lung at all.

Connect up your loop hoses, if you dive a shrimp, you can use thing 6022070 to couple your loop hoses together without the shrimp in place.

Use a solid bung, or a cork on the top of the exhale side T piece, and un-thread your exhale OPV / dump valve to allow the blower to vent out of the exhale side OPV.