Duotight ball disconnects - experiences?

[mashdar]

I was curious, and bought a few Duotight FC ball lock disconnects for testing. As others here, I found them to be really tight. It was nearly impossible to get them locked on to some posts. Looks like it depends on how far down the post poppet can be pushed, because connecting the Duotight without center pin was ok.

After some measuring vs CMB disconnects, I found out maybe the center pin is slightly too long. All other measures seeems to be identical.
I cut down the center pin (in the thick end) 0.5-0.7mm. Now, all combinations I have tested are ok. I have also lubed balls and locking ring to make it move more smooth.
So far, I'm quite happy with the (modified) Duotight FC's. Remains to see how long time they last.

@KegLand might find that interesting

 

[Bobby_M]

I was curious, and bought a few Duotight FC ball lock disconnects for testing. As others here, I found them to be really tight. It was nearly impossible to get them locked on to some posts. Looks like it depends on how far down the post poppet can be pushed, because connecting the Duotight without center pin was ok.

After some measuring vs CMB disconnects, I found out maybe the center pin is slightly too long. All other measures seeems to be identical.
I cut down the center pin (in the thick end) 0.5-0.7mm. Now, all combinations I have tested are ok. I have also lubed balls and locking ring to make it move more smooth.
So far, I'm quite happy with the (modified) Duotight FC's. Remains to see how long time they last.

Very interesting and I'm disappointed that I hadn't thought to compare the poppets a long time ago. It probably has a lot to do with whether the kegs have universal poppets or not. The springs on some of those are quite sturdy and long. Nice to know half a mm can make all the difference.

 

[larsh]

Very interesting and I'm disappointed that I hadn't thought to compare the poppets a long time ago. It probably has a lot to do with whether the kegs have universal poppets or not. The springs on some of those are quite sturdy and long. Nice to know half a mm can make all the difference.

It is all about stroke length of the center pin. The FC -construction seems to be very tolerance-dependant, e.g. how hard the top and bottom parts are screwed together.
I could have achieved the same result by:
* Thicker o-ring between bottom and top parts.
Not possible, as it is sqeezed between the two parts.
* Cut ~0.5mm off the center pin guide tube/ end stop.
Not possible, at least on the FC. It is situated inside a "cup".
Maybe on the non-FC, which I do not have.

 

[day_trippr]

Not possible, at least on the FC. It is situated inside a "cup".

Use a drill...

Cheers!

 

[balrog]

In my limited Bridgeport machining experience, using my Harbor Freight floor stand drill press, I cannot imagine thinking I'd be able to make a 1/2mm deeper hole.

Then again, I doubt I could shave 1/2mm off the post without flinging said poppet post into the farthest sawdusty corner of my shop, under the never to be used but must be kept scraps, ethereally close to the Single Lost Dryer Sock parallel universe.

 

[mashdar]

Why can't we file the pin? I'm missing something.

 

[day_trippr]

In my limited Bridgeport machining experience, using my Harbor Freight floor stand drill press, I cannot imagine thinking I'd be able to make a 1/2mm deeper hole.

If you know your way around a CNC machine you know how to fixture stuff and pick a bit or burr that is only as aggressive as the job requires.

In this case - using my 50-something year old DeWalt floor standing drill press, an XY table clamp, and a flat top burr from my Dremel collection - it'd be a piece o' cake to dock that QD plunger a half mm

Cheers!

 

[DuncB]

I'd have thought a little mark with a pen and then rub on some sandpaper would do the trick.

The engineers might not agree!

 

[day_trippr]

I was referring to milling down the end sleeve that the plunger slides in - that thing molded inside the other thing

Cheers!

 

[larsh]

I'd have thought a little mark with a pen and then rub on some sandpaper would do the trick.

The engineers might not agree!

I do agree!
I just measured the original length with a caliper and adjusted it half a mm as a reference.
Then cut off a slice with a wallpaper knife and rubbed with 800grade sandpaper until the tip was 90degrees, flat and according to the new reference length.
The pin is nylon'ish. Easy to cut.

 

[Unicorn_Platypus]

Does anyone know of a tool I can use to unscrew the cap when disassembling the disconnects?

Its supposed to be done by hand, but sometimes its just not possible with sticky build up.

Generally I'm able to gently use a needle nose pliers, but that even sometimes doesn't work.

Its annoying they didn't make these caps functional with a wrench or screwdriver

@Bobby_M any suggestions?

 

[Deadalus]

Does anyone know of a tool I can use to unscrew the cap when disassembling the disconnects?

Its supposed to be done by hand, but sometimes its just not possible with sticky build up.

Generally I'm able to gently use a needle nose pliers, but that even sometimes doesn't work.

Its annoying they didn't make these caps functional with a wrench or screwdriver

@Bobby_M any suggestions?

Wrap the cap in a piece of cloth, not too thin, not too thick, and use a pair of channel locks. You don't want the teeth contacting the cap through the cloth. This can be done with brass fittings or if you have a pipe nipple without a hex portion. Generally works but sometimes a slip may create scratches so go slow and make sure the grip is solid.

 

[matt_m]

I 3d printed one from Printables.com

 

[mashdar]

I just use regular old pliers if they're really stuck. If they're stuck worse than that, it's possible you're over-tightening them. Most of the time I can palm them with my shirt over them. I only finger tighten and haven't had any leaks. (YFMV. Your fingers may vary.) In my experience, most people overtighten most things if they are physically able.

Is this on liquid or gas? I don't use the liquid ones for lines, only transfers etc. I also disassemble to clean every time. Maybe my usage doesn't produce the sticking.

 

[Unicorn_Platypus]

I just use regular old pliers if they're really stuck. If they're stuck worse than that, it's possible you're over-tightening them. Most of the time I can palm them with my shirt over them. I only finger tighten and haven't had any leaks. (YFMV. Your fingers may vary.) In my experience, most people overtighten most things if they are physically able.

Is this on liquid or gas? I don't use the liquid ones for lines, only transfers etc. I also disassemble to clean every time. Maybe my usage doesn't produce the sticking.

Both liquid and gas. I'd say it happens 1/5 times. I generally am careful on most of my kegging gear as not to overnighten as not to strip threads

 

[Unicorn_Platypus]

Wrap the cap in a piece of cloth, not too thin, not too thick, and use a pair of channel locks. You don't want the teeth contacting the cap through the cloth. This can be done with brass fittings or if you have a pipe nipple without a hex portion. Generally works but sometimes a slip may create scratches so go slow and make sure the grip is solid.

Thanks. Wouldn't it make so much more sense if the just had a flathead slot like the CMBs or could take a spanner wrench like their carbonation caps

 

[mashdar]

Thanks. Wouldn't it make so much more sense if the just had a flathead slot like the CMBs or could take a spanner wrench like their carbonation caps

I'd definitely support a change to hex lids. @KegLand have you considered a 12mm or w/e outer hex on the DuoTight QD lids? (Maybe there's a reason this is harder than it seems?)

 

[Indian_villager]

I think these disconnects are fine. My biggest gripe with them is that they don't come with retaining clips from the factory. I lost a 20# CO2 tank and dumped a whole keg of seltzer into my keezer (carbstone dip tube). Because the tube popped out of the connector. So here is a printable clip for anyone who needs it.
https://www.printables.com/model/778248-95mm-duotight-retaining-clip

 

[DuncB]

I think these disconnects are fine. My biggest gripe with them is that they don't come with retaining clips from the factory. I lost a 20# CO2 tank and dumped a whole keg of seltzer into my keezer (carbstone dip tube). Because the tube popped out of the connector. So here is a printable clip for anyone who needs it.
https://www.printables.com/model/778248-95mm-duotight-retaining-clip

Put this brilliance in the 3d print thread as well.

 

[Bobby_M]

The retainer clips are fine to use, but FYI you can "set" the teeth into the EVA tubing by giving a gentle pull on the tubing once you have it fully seated. It's kind of like setting the hook when you get a bite fishing.

 

[mashdar]

: )

 

[day_trippr]

I'm betting typo...

 

[Bobby_M]

I'm betting typo...

correct and corrected

 

[UdonPete]

I think these disconnects are fine. My biggest gripe with them is that they don't come with retaining clips from the factory. I lost a 20# CO2 tank and dumped a whole keg of seltzer into my keezer (carbstone dip tube). Because the tube popped out of the connector. So here is a printable clip for anyone who needs it.
https://www.printables.com/model/778248-95mm-duotight-retainin

Not worth the trouble, so cheap to buy ?

https://www.aliexpress.com/item/100....new_all_items_2007599352852.1005003091187189

 

[Indian_villager]

Not worth the trouble, so cheap to buy ?

https://www.aliexpress.com/item/1005003091187189.html?pdp_npi=4@dis!USD!US $0.50!US $0.50!!!0.50!0.50!@210133e017122020745492441e1074!12000024024737541!sh!TH!134711501!&spm=a2g0o.store_pc_allItems_or_groupList.new_all_items_2007599352852.1005003091187189

Had a gathering the next day an no one was going to ship me the clips in time. However my printer can rattle off about 15 of these in 15 mins.

 

[Indian_villager]

The retainer clips are fine to use, but FYI you can "set" the teeth into the EVA tubing by giving a gentle pull on the tubing once you have it fully seated. It's kind of like setting the hook when you get a bite fishing.

Sorry for the double post. I did try that initially. However this fitting blew the tubing all the way out. I think i just fell into a bad range of tolerance stack between the eva barrier tubing and this particular fitting. Of the 5 disconnects I bought only one gave me grief. But it got clips on all of them just in case.

 

[beren]

I believe these fit the duotight stuff too https://www.amazon.com/dp/B00YGR576K