Waterproof Servo Selection

[BruceM]

I am looking for a servo capable of working when submerged.

FWIW I am setting up a retractable mast system on my 1/72 ALFA sub.

At least an IP67 would do the job and I also need it to be small size if possible.
Amazon lists several quoted to be IP68 but I really have my suspicions about these being able to meet even IP67.
Hitec has a selection of IP67 models and I am inclined to try one of these, particularly since they are a reputable make.

My question is whether there are other manufacturer's servos out there that people have used with success.

Thanks
Bruce

[timsenecal]

I have used both the hitec and savox brand waterproof servos, they both work reasonably well. Basically just make sure you design your setup so that you can replace the servos when they fail.

[BruceM]

Thanks timsenecal

Point taken about ease of replacement.

I see that the Savox SW-0250MGP would be a suitable choice for me and a bit less expensive than a Hitek HS5086WP.

It is a digital servo so presumably can be programmed to particular settings however I cannot find any information whether this is possible.
In particular I want to slow down the servo velocity to make a more realistic mast raising speed.

So have you been able to program a SAVOX?

Thanks
Bruce

[Occupant]

I have used both the hitec and savox brand waterproof servos, they both work reasonably well. Basically just make sure you design your setup so that you can replace the servos when they fail.

When they fail... speaking from experience? How much life can you expect on a servo? is there a good pre/post run maintenance to prolong life of the servos?

[Subculture]

So many factors can influence the life of a servo, including its design e.g. brushed or brushless, magnetic induction feedback or simple carbon potentiometer, materials used for the gear train etc. etc.

[timsenecal]

The truth is that none of them are actually water proof, especially the 3 wire cable leading to the receiver, since it is a standard servo connector. It WILL corrode, and will need to be replaced. How often depends entirely on how often you run the boat, and what kind of particulates are in the water. Even with the digital servos, i do not actually program them beyond their "standard" operation, basically treating them as an anolog servo. KISS principle

[timsenecal]

As to designing a submarine to be maintained, I always build my subs so that any single part can be replaced in less than 15 minutes. There is no reason to build something that can't be maintained/repaired with little to no hassle.

[Subculture]

I remember reading something about Graham Hawkes (formerly of Deepflight) speaking about the difficulties he and team had when designing underwater robotic arms/manipulators. They spent a great deal of effort trying to get the moving parts sealed with little success, before realising the best approach was to stop fighting the water and simply build parts that were designed to work in water. However such an approach for our hobby would require a lot of custom work.

[Timothy L]

Wouldn’t liquid electrical tape be a practical way to solve the connection problem?

[RCENGR]

Liquid electrical tape works good initially. It tends to separate from the parts over time, allowing water to get in. Great for insulating, not for waterproofing. 3M makes a coating called Scotchkote Electrical Coating FD that does work well at waterproofing. But it's expensive and a gooey mess to work with.