Despite what you might think about servos most are water-resistant at best. The first thing you might want to do is take apart your servo and look inside. Notice there is a rubber O-ring on the edge these rings are there to seal your servo from water. However, the main place water will enter your servo is via the actuator shaft. Sealing that shaft is often the most difficult part.

It is important to note here that before you try any of these methods you might want to first try it on an old servo you don’t care about. I offer no guarantees or promises on any of these techniques.

So here they are from worst to best order.

The Balloon Method
One of the most commonly used methods for waterproofing servos and receivers is the balloon method. For this you take a common balloon and squeeze your sever down into it. You then cut a small hole in the balloon and push the actuator head up through the hole. The key here is to make the hole smaller than the head of the actuator. Then you run the wires back out the hole and zip tie them. This method will work for snow and some light mud but it is definitely not water PROOF.

Plasti Dip Method
This method is slightly better than the balloon method, but it still leaves the actuator shaft exposed some what. You can purchase Plasti Dip from most auto parts stores or home improvement store. It comes in a couple of flavors, dip and spray. Once you coat the servo with the Plasti Dip hang it up and let it dry. The biggest issue you will have with this method is once coated the shell of the servo is now a few millimeters thicker. If your servo needs to fit in a predefined size slot this method will not work for you. Also once again your actuator shaft is exposed to possible water leaks. Again this will make your servo more water resistant but not waterproof. One idea you might try is to put a small red shock O-ring around your actuator head before you mount your servo horn. This will help to seal the shaft better. Also put a bit of old on the O-ring to help repeal water and reduce friction. NOTE: make sure your sealant oil is not the same material as the O-ring (for example, don’t use silicone oil with a silicone O-ring).

Super Glue and O-ring Method
Basically this method is the same as the Plasti Dip Method only instead of dipping the whole servo you are super gluing the sections of the servo together. Start by taking apart your servo and then super gluing each part back together (be careful not to get glue on the gears). Then re-screw it all back. Next put a blob of glue where the wires go into the servo body. Lastly add a O-ring to the actuator head as stated in the previous method. This should waterproof your servo for heavy water use.

There is an additional step you could perform before you do the super gluing. That is to fill the servos with non-conductive oil. There are a number of oils you could try such as cooking oil, mineral oil, or silicone oil.

To do this you need oil, a wide container that holds oil, gloves, super glue (something that dries in under 5 minutes), a screwdriver, and either acetone or hexane. Tweezers are also recommended, but optional.

The first step is to poor the oil into your container. You want about one to two inches of oil (or enough to completely cover your servo). You may also want your container to be inside a second container, to avoid spilling oil everywhere. Choosing a container that BOTH of your hands can operate in is very important.

Now you should disassemble your servo, and put all parts in the oil. Make sure you shake out all of the bubbles.

Ok now the really hard part, reassemble the servos while they are fully submersed in oil! Make sure you practice disassembling and reassembling the servo outside the container a few times before trying to reassemble in oil. Its 10x harder to do it in oil, so practice is good.

A few potential issues, handling the tiny screws of a micro servos while wearing gloves is a challenge. Using tweezers to pick and place the screws could save you tons of time. The oil is also optically distorting, making it hard to see what you are doing. Make sure you have good lighting. You might also have trouble operating the screwdriver, since your gloved hands are covered in slippery oil. Make sure you use a screwdriver with a good grip handle.

After you get the O-ring and servo horn on, and you make sure the servo is screwed together really well, take the servo out of the oil and clean it off. To do this, dab it with a paper towel that is lightly soaked in acetone or hexane (dissolves oils). Both give off fumes (especially hexane) so do this in a well ventilated area. Neither chemical damages the servo casing, but acetone can potentially dissolve the plastic gears and electronics, so be careful. NOTE: Acetone can also dissolve screwdriver handles.

Lastly, apply the super glue (that is designed for plastics) to all the seals.

To verify that your seal is good, let the servo sit out for a day or so. Come back and if any oil is still leaking, clean it off and apply more superglue to that area.

Cons: Superglue isn’t that permanent and acetone and hexane can dissolve the glue. Also over time the oil will start to leak out.

Super Glue and O-ring Method On Steroids
The last method is another spin on the super glue method. It is easier to watch this video than try to explain it.

Down load a set of RCgawker stickers to stick on your rc model. This is set up to print to 2×4 label sheets.

For starters you will need to decide what sort of sticker you want to put on your RC model. In my case I wanted to put my web site logo on my RC car. You can use any graphics editing software such as Photoshop, Corel, Illustrator, Pixelmator (Mac OSX), even MS Word. As long as you can print to a color printer you should be good. You can “gang up” as many logo’s or images you want on a single sheet of paper, just be sure to leave enough room to cut them out.

In my case I used Adobe Illustrator to create my site logo and print my stickers. After you have settled on your art work the next thing you will need to do is get clear labels. Avery makes a clear label that works perfect for this. You can get them in full 8 1/2 X 11 sheets from Office Max or Staples or order them online. They come in Laser or Ink Jet printer style, make sure to get the correct one for the printer you are using.

Once you have printed out the artwork on the clear paper you will want to apply some clear package tape over them. The reason for this is twofold, first it provides a rich glossy shine to your stickers, secondly it protects the sticker from weather and scratches.

That’s pretty much it. Cut out your stickers and enjoy

1. Choosing a chassis – One of the first things you will want to do is choose a chassis with a low center of gravity. As obvious as this sounds it is sometimes over looked. You want to keep every ounce of weight as low to the ground as you can when climbing a steep incline. If your weight is not distributed correctly you run the risk of rolling your RC rock crawler over on it side.

2. Tires – For tires you’re going to want soft, large tires with a pronounced tread pattern for maximum ground clearance and grip. If you run the tires without foam inserts to allow them to flex but the tires don’t support your truck adequately, then look to soft inserts for support. The reason you want soft tires is that you want your tire to flatten out and give under the weight of the crawler. This is the same effect as deflating your tires in a full size crawler. This will give you maximum traction during the climb.

TIP: To soften hard tires try spraying a little WD-40 on them.

Cons: A little heavier, a little more expensive, some say to much effort to change tires.

4. Suspension – When it comes to RC rock crawling the suspension is the main ingredient, but not just any suspension will do. Articulation is the key here, but an independent A-arm type will not allow you to get the adequate articulation required. What you will need is a solid front and rear axle with a 4-link suspension. This will allow for maximum articulation and grip.

TIP: For maximum axle articulation keep your shock and spring combination soft.

5. Locked differentials – In most RC cars differentials are a must, but not when it comes to crawling. This is the most important modification you will need to do. If you don’t have locked differentials the power will be sent to the opposite wheel that isn’t under load. By having locked differentials the wheel maintains constant power when going over rocks. Locking out the differentials can be done a number of different ways: epoxy, JB Weld, or you can purchase lockers.

MORE HELPFUL TIPS: Four wheel steering, forward mounting your battery, mount your steering servos on top of each axle.

If you enjoyed this article please click on one of my sponsors, help me support this site. ]]> http://www.rcgawker.com/2009/07/how-to-build-your-own-rc-rock-crawler/feed/ 1