Home        Store        Docs        Blog

Tether Quick Disconnect


(Joe) #21

Has anyone looked into using a bulkhead connector in the Acrylic end cap and then using a non pig tail plug for the tether, the type of plug that the tether is past through a gland or O-ring and the connection is made inside of the plug. An example is Seacon MIN E-BCR and MIN-CCP (http://seaconworldwide.com/wp-content/uploads/MINI-CON.pdf)

I just ordered a cheap chinese set like mentioned above for my new tether ( http://www.weipuconnector.com/pro_show_108.htm) the problem I will have to overcome with the one I purchased is the threads for the bulkhead connector are not long enough to go through the 1/2" thick Acrylic cap to install the nut. I am thinking I will try to tap threads in the Acrylic cap and then thread and glue the connector in my cap. The plug I bought is rated IP68 and of coarse it may leak (in the pins not the hull) but in my present home built ROV I am using a similar style and it has worked OK


(Kevin) #22

Joe,

I have a Micro Wet-Con bulkhead connector (MCBH3F) that was to be used on another project. It is about 1-2mm too wide for the standard penetrator holes. I don’t recommend boring them out unless you have a precision drill press and even that may lead to watertight issues.


(Paul) #23

@Joe,

I tried a set of these ( http://www.vetco.net/catalog/product_info.php?products_id=17507 ) and had problems getting a good solder joint and a good seal.

So I scrapped that idea and bought several sets of these ( http://www.ebay.com/itm/171570268125 ) and am much happier with them. Much easier to work with and the cable is only slightly smaller in diameter than the BR tether. I’ve not had an opportunity to test them to any great depth yet.

Paul


(Mark Langille) #24

Is your plan to run these through the BR penetrator? and then splice the other end to the BR tether?


(Joe) #25

Kevin thanks for the heads up

I have an extra end cap to test on but have drill presses, mill ect.

The Seacon connector listed above I believe fit the penetrator holes that the cap has if not the MIN D will

The MIN E-BCR has an o-ring against the face and not in the bore so it doesn’t have to have a perfect bore like the style you listed, probably wont go as deep as the one you listed but has the same amount of sealing as the BR penetrators, a single O-ring against the face

Joe

 

 

 


(Joe) #26

Sorry didn’t see Schoonerlabs and Pauls posts

Schoonerlabs

Yes the Seacon bulkhead connector would install in the BR end cap penetrator hole with out any issues that I can see, The plug end Min-CCP would have the BR tether inserted into it and connections made inside the plug. This would not require an inline splice like using a pig tail type connector. You would have to make sure you get the correct end for the diameter (gland) of the BR tether

At this time I am not using a BR tether but a AV cable mated to floating rope, this is a fragile set up but have used my old one for 3+ years and am now re-building my ROV with a BR 4" Acrylic hull so building a new tether

Paul

What didn’t work on the other style you tried? What method did you use to mate the BR tether to the pigtail (solder, crimp? layers of shrink ect)

I just made my new tether with that type of pigtail plug and was not happy at all with the my splice even on the third try. So the reason with going to try the bulkhead connector and matching plug. I used a similar set up on my present hull and was happy with it.

Joe


(Paul) #27

Once I’m satisfied the connectors are water-tight when connected, yes, that is my plan.


(Paul) #28
What didn’t work on the other style you tried?
I never got a good electrical connection and was never happy with the seals. The connectors were made from a fairly weak plastic which I think contributed to the issues.
What method did you use to mate the BR tether to the pigtail (solder, crimp? layers of shrink ect)
First method for the pigtail to tether splice is to solder and use glue-filled heat shrink on each wire. Follow with a liberal application of "liquid electrical tape". Followed by 2 layers of glue-filled heat shrink.

If that doesn’t work well enough, I’ll try potting the entire splice.

Again, I’ve only done some preliminary tests. Not certain this will work yet.


(Joe) #29

Back up and running with new BR 4" enclosure and end cap with above mentioned( http://www.weipuconnector.com/pro_show_108.htm) quick disconnect plug

The fun part was cutting 13mm 1.0 pitch threads into the end cap

Pardon the mess of epoxy on the wires should have masked them off before potting Also really recommend getting the syringe from BR to fill into the penetrators

Joe



(Shannon) #30

Here is my version. Parts are shown in pictures, look closely for suppliers. Turned out very nice, don’t expect any issue. About $125 spent, the 3M molding kit was about $75 of it.

(Sorry about duplicate pics, upload was sketchy, wont let me delete. Maybe admin can clean up)













Tether repair or joint
(Mark Langille) #31

Rusty - There been any progress on a tether disconnect?


(Rusty) #32

@schoonerlabs - Yes, there’s been a lot of progress but nothing I can share quite yet, unfortunately. We’re hoping to have something available around May.


(Todd Sparkes) #33

A quick connect on the tether has many benefits. The one thing you don’t want is to lose control or have a dead ROV due to water ingress into a connector. If you are using your ROV for work purposes I recommend paying a few dollars for a good connector such as a SEACON inline connector. Connectors the same as anything else are rated for a purpose. Using connectors which are not rated for subsea use is asking for trouble.


(Bo Koppel) #34

For cheaper Projects I use Bulgin Buccanner 2 to 7 poles
They are rated 100 msw, cost around 15US$
http://www.bulgin.com/products/circular-power-connectors/standard.html


(undersearobotics.com) #35

I’m not sure I’d trust that “100 msw” rating. I’ve used them as topside connectors but I wouldn’t use them for anything that was fully submerged.


(Todd Sparkes) #36

I agree with you Paul. I have seen a lot of fully rated connectors fail in under 100 meters of seawater.


(Mark Langille) #37

Rusty - Any more word on the tether disconnect?


(Rusty) #38

Mark,

Still making progress! It takes a long time to move from a functional prototype to full production. We’re currently waiting on some tooling to be completed for rubber molding.

-Rusty


(Mark Langille) #39

Thanks for the update. If you need some testing I’d be happy to try anything out on our setup to assist.


(Tim Pierce) #40

Are you pouring actual hot mold rouber or using something like cold mix scotchcast? The cold mix stuff will reportedly not stick to ABS plastic so a 3d printed mold is possible.

I’ll let you know for sure after this weekend if I get that far on my tether build.