At OpenROV one of the improvements that we have been working on is developing new battery tubes. The most recent version uses a twist lock to keep the endcaps secured and the O-rings seated properly. This means that straps will no longer be needed and that the endcaps should always seal the battery tube. Additionally, by having the endcaps fully removable, they can be unmounted from the ROV and stored in a separate bags in order to keep the O-rings clean during storage. The final improvement is that the polyfuses are now incorporated into the back of the battery tube so battery adapters are no longer needed. Any advice or feedback?
Very nice…! Will this be available for purchase and upgrade of existing ROV models?
No issues with the end caps, I think the change is great.
A bit on the ranger bands…Have you tested them extensively in seawater? One of the things I liked about the 2.7 battery straps was that they were NOT rubber and a bit more suitable and rugged for seawater use that the old 2.5/2.6 O-rings. I just don’t want anything to fall apart on users 4-5 months down the road. My 2.7 is still holding up like a champ and my old 2.6 is in pieces.
Is the same change being made to the E-tube? I think that’s just as prone to water leakage and in need of a new design.
Glad to hear that this is happening! Would have helped yesterday when water leaked into the E-tube (and slightly into the battery tubes) during a test run…
The locks for the battery tube end caps are just to keep the end cap from popping out. The o-rings are still responsible for keeping the water out.
The B-Tubes need the assistance because they are inclined to slide out due to spring/pressure. The E-Tube tends to stay put because it has no spring, but also you pullout the syringe plug to close the end cap and then when you put it back in, the air pressure inside holds the end cap in place.
The rubber bands that would hold the battery tubes on are called Ranger bands and are made of a material called EPDM which is the same material used as the waterproofing membrane on certain types of roofs. It is environmentally stable and should not rot or decay unlike the old O-rings used to seal the battery tubes which had to be periodically replaced. We have done some testing on it so far, but not a ton yet. However, we do feel fairly confident in the material.
You can read more up on the material at its Wikipedia page below
Additionally, we have been working on a new OpenROV E-tube endcap which incorporates the DB-25 connector into the endcap. The thought behind this is that the DB-25 will now never have the risk of coming out of the connector. It should also free up space in the E-tube for the wire bundle does not have to pass through the E-tube which would enable the E-tube to slide over the electronics easier. Let me know your thoughts!
I like it! Both the twist lock endcaps (which I’ll buy once they’re available) and the new E-tube endcap. My wire bundle ended up at the right length, but I found that to get the tube to slide down, I had to press the bundle against the electronics and I just noticed the pins were nicking the insulation. I’ve wrapped it all in electrical tape to prevent any more of that. Something like this would definitely free up some room in there and offer more protection.
This seems to be a much cleaner endcap build, improving clearances down the length of the E-tube. From your photo, it 's hard to tell if the harness end of the DB-25 is a fixed attachment to the endcap. Might be worth assessing whether some flex there might be better. It might allow the tolerances for DB-25 placement to be less critical during end cap build and minimize chances of torsional stress on the DB-25 connection.
Great to see how OpenROV just keeps getting better!
Because the female end of the DB25 is potted into the endcap with epoxy it might be hard to incorporate some minor flex into it, however the male end of the adapter is purposefully not bolted to the sidewall so it does have a fair amount of give to in to enable it to adapt to slight misalignment. Hopefully this should take care of minor build errors.
Good enough, Patrick. Looking forward to both upgrades