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Most modern RC trucks and rock crawlers come with some waterproof electronic components, while others don’t. If you are among the unfortunate ones and don’t have waterproof electronics or if you are wanting to waterproof the entire vehicle there is no need to worry, there’s a way to fix that.
Whenever you expose metal components to water, the chances of corrosion and rust greatly increases so that is another thing to keep in mind when exposing your RC crawler to water. Examples of those components that can corrode and rust are: axles, bearings, linkages, screws, etc.
Once your rock crawler gets wet, make sure you dry it completely, and any water that is pooling has been removed even if you have waterproofed the electronics.
In most cases you will need to waterproof each part of the RC rock crawler separately and the process for each is different as well.
To see how to completely waterproof an RC rock crawler even to the point of it being submerged then check out the video below.
Waterproofing the motor
The motor actually doesn’t require any waterproofing at all. Underwater submersion is even a method that many people use to break in their electric motor. Make sure that it is thoroughly dried after you get it wet; otherwise, you will have a ton of corrosion issues.
All of the bearings within the engine will require oil, so after getting your rock crawler drenched, remember to re-lube them.
Many people believe that servos operate like small motors with gears, so there is no need to protect them. It might make sense until you realize that there is a circuit board that modulates the servo rotation and it’s incredibly tough to get the water out once it enters the servo box.
Balloon method– make a hole smaller than the output shaft through the balloon. Expand the diameter; install the control horn over the servo. Remember, this will keep it waterproof, but not submersion proof. Zip tie the open end of the balloon and you’re ready to go.
Plasti–dipmethod- this is the most preferred method for many people as it’s more permanent than the balloon method. Plasti-dip is a soft gooey liquid that leaves a rubbery film over anything that gets dipped into it. Buy yourself some plasti-dip and go on with the process of dropping your servo in. Ensure you lower it by using the output shaft or you can use silicone sealant as well. Make sure that the gap between the output shaft and the servo housing is entirely tight.
Silicone sealant– results in a stock like appearance, as you can’t tell that anything has been done to the servo. Take the servo case halves apart and apply a small bead of silicone where they connect together. Then reassemble the case and allow the silicone time to cure. To protect the area around the servo output shaft, use a small O-ring coated with some grease to form a seal when you install a servo horn.
The essential component you definitely have to waterproof is the receiver. It’s the hub of all communication among you, itself, the speed control, and the servos and if you damage it it is one of the most expensive components to replace.
Many receivers in RC cars come in a receiver box, where the lines run in and out of the box with neat little holes cut out. Any receiver box you have can work with any RC vehicle and all you will need is a silicone sealant to seal the small gaps.
If you are creative enough, you can even make your own waterproof receiver box. If you don’t own a receiver box, simply use the balloon method, the same way we did with the servo above. When using this method, don’t cut more holes. Use the balloon entrance to run the entire antenna through, and then wrap up tight with a zip tie.
Waterproofing your speed controller
As per the priority, the speed controller and receiver are the components that you should be waterproofing first. As important as the speed controller is, it’s a bit more tiresome to waterproof. This is because you can’t encase it in a balloon or some small container because, as you probably already know, the speed controller gets hot and needs proper ventilation. The aim here is to preserve your electronics not damage them,
This might require some trial and error and continuous temperature checking to make sure it does not overheat.
Fortunately, rock crawlers don’t get as hot as faster RC cars, but still, it’s a concern to keep in mind. The best option is to buy a waterproof ESC. If not, then you will have to do the waterproofing yourself. The concept is similar to how you would waterproof a receiver, except you cannot use the balloon method.
In case your ESC has fins, and you can cut appropriate fin slips in the plastic container and seal the edges with silicone sealant.
Miscellaneous component waterproofing
The miscellaneous components that need to be waterproofed can be wrapped tightly in electrical tape and a light silicone spray should do the trick. You can also use silicone sealant as it works well. The aim is to keep all electrical leads separate in any ionic substance.
When cleaning off the rock crawler after a water splashing session, remember to lube all of the components. WD-40 is typically the best to keep all of the bearings lubricated and metal parts protected.
The crucial components to look for when shopping for an RC crawler
Ground clearance: you need to be able to get up and over items. Chassis rail design, multi-link arms, and clever portal axles all help with this.
Suspension: not long travel but well-damped with consistent performance and droop to ensure contact is kept with the terrain.
Waterproof electronics: a core part of serious off-roading is taking on puddles, rivers, and streams—your electronics need to be ready for this.
Locking differentials: often tackling loose surfaces or climbing with one wheel in the air requires a locked differential and a switchable unit is preferable.
Grippy tires: soft compound, deep tread, large sidewalls with foam inserts.
Good steering: a strong servo hooked up to balance linkages that can resist the weight of the vehicle when hung off a rock, sat on just one wheel.
Torque motor: commonly brushed units typically high turn motors with plenty of torque.
Gear ratios: transmission designed to maximize motor torque and provide low-speed control.
Balance: low center of gravity and even weight distribution will help you maintain control.
Crawler specific ESC: one with excellent throttle control and a drag brake.
It’s very crucial to waterproof your RC rock crawler electrical components, for this will make them last for much longer and will also allow you to keep them working properly. If you don’t waterproof everything and end up submerging your crawler it can be quite expensive to replace all of the damaged parts!
It’s also essential you follow what’s in this article to avoid messing up your rock crawler components when going through the process. Watching the entire video that is at the start of this article will help you a lot in showing exactly where you need to waterproof and how to do it.
If you have a rock crawler component that needs waterproofing, it’s much easier to do it before you ever hit the trail then it is to not do it until it’s too late!