Submersible servo


Does anyone have a sure fire way to waterproof a servo for 15 metres depth, or know of one I can buy?

I used a HobbyKing waterproof servo that had o-rings (even on main shaft). But it failed in stantly in a few metres of sea water. So how to waterproof this servo.

I have read about using marine grease, or mineral oil, with oring on splines, but is there a way that someone has used and proven to work?

The servo would need to do a few movements every day at 15 metres depth for 3 weeks. It will be submerged almost the whole time.

My idea was to pack every part of it with non conductive marine grease. Then cover in liquid tape, and use o-ring on output shaft. I would still be worried about the wire entry point and the in put shaft.

I would love to know your experiences.


Hi Damien,

My company sells submersible servos at These are good down to 100 meters depth and are tested at that depth for 12 hours before shipping out. Since these are very high-quality units, the price is about $380, depending on connector options.

If there is interest, I may offer a kit in the future which would bring the cost down to less than $200.

Damon McMillan

Redirecting... …300m Servos :wink:

Hi, just wanted to follow up on this! Did the marine grease method work for you? Or what ended up being your solution?

I’m also facing a similar obstacle so I would appreciate any insight :slight_smile: