Trip
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I live in Michigan and in the winter I like to run my FG's in the snow. That's a problem if you have any Hitec "Water and Dust Resistant" servos. This thread is about what goes wrong and how to fix the problem before you smoke that $125+ servo the way I have.
I've had 6 Hitec digital servos and they all have the same problem, I keep blowing them up. If you have a servo that is getting to be a few months old, you will have this problem as well.
Lets begin.
I have been having problems with all of my Hitec digital servos, they keep going up in smoke. Here is where all of them melt the lower portion of the case.
If you look on the side of the case, this is what was causing all the problems... In the circled area is one of the factory installed O-Rings, the arrows are pointing to where the O-Rings are missing. The bottom arrow was a mistake, sorry.
After I rubbed the O-Ring with my finger it broke in another place.
Here is another pic, this was taken so you can see the servo it happened to...
You can see how small the Gasket really is.
Here is what happens when water gets in past the faulty O-Rings...
Hitec uses 3 O-Rings to "Seal" up their 7955 servo, while this is great when the servos are new, but as the servo ages the O-Rings breakdown and rot. I didn't realize how bad this problem was until I tore all 6 of my $100+ servos apart. They are all burnt up in the same spot. Any R/C that burns fuel is going to have this problem from the exhaust gases and oils eating the neoprene that the seals are made from. My problem was water, but dust and dirt will get in there too.
So my suggestion is if you have a Digital or "Dust/Water Resistant" Hitec servo, pull it out of your rig and seal it up correctly, because Hitec doesn't use a quality seal.
Seal yours up before this happens to you because Hitec WILL NOT WARRANTY your servo if this happens! Trust me, I have 5 that were sent back from them! They will insist you buy another one, or you can do what I did and buy an Airtronics 94780... http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWDH9&P=7 More torque and it's 2 bucks cheaper, plus Airtronics servos have never blown up on me! :celebrate:
I know it's not Hitec's fault, :lol:they just build them, test them, research them, etc, but I guess they never have had them for more than 6 mos?
Anyway,
How to seal your $125.00 servos the way Hitec should have...
After reassembly you can cut off the excess silicone with a razorblade or an X-Acto blade.
For the ultimate seal, wrap the outside of the servo seals with 2 layers of electrical tape, that will seal it up quite well. You can also blob a spot of silicone, grease, Vaseline or any other water repellent substance on the servo spline under the horn. Then cover everything with a shot of "Camp Dry", that's how I used to seal up my servos back in the old days.
I can't believe this has to be done to a "Premium Servo" I haven't done this since back in the 80's when there was no such thing as a waterproof/resistant servo. As far as I am concerned, this is something I should NOT have to do on a 125 dollar servo! I don't have to do this with my other name-brand servos!
C'mon Hitec, get with the program.
I've had 6 Hitec digital servos and they all have the same problem, I keep blowing them up. If you have a servo that is getting to be a few months old, you will have this problem as well.
Lets begin.
I have been having problems with all of my Hitec digital servos, they keep going up in smoke. Here is where all of them melt the lower portion of the case.
If you look on the side of the case, this is what was causing all the problems... In the circled area is one of the factory installed O-Rings, the arrows are pointing to where the O-Rings are missing. The bottom arrow was a mistake, sorry.
After I rubbed the O-Ring with my finger it broke in another place.
Here is another pic, this was taken so you can see the servo it happened to...
You can see how small the Gasket really is.
Here is what happens when water gets in past the faulty O-Rings...
Hitec uses 3 O-Rings to "Seal" up their 7955 servo, while this is great when the servos are new, but as the servo ages the O-Rings breakdown and rot. I didn't realize how bad this problem was until I tore all 6 of my $100+ servos apart. They are all burnt up in the same spot. Any R/C that burns fuel is going to have this problem from the exhaust gases and oils eating the neoprene that the seals are made from. My problem was water, but dust and dirt will get in there too.
So my suggestion is if you have a Digital or "Dust/Water Resistant" Hitec servo, pull it out of your rig and seal it up correctly, because Hitec doesn't use a quality seal.
Seal yours up before this happens to you because Hitec WILL NOT WARRANTY your servo if this happens! Trust me, I have 5 that were sent back from them! They will insist you buy another one, or you can do what I did and buy an Airtronics 94780... http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWDH9&P=7 More torque and it's 2 bucks cheaper, plus Airtronics servos have never blown up on me! :celebrate:
I know it's not Hitec's fault, :lol:they just build them, test them, research them, etc, but I guess they never have had them for more than 6 mos?
Anyway,
How to seal your $125.00 servos the way Hitec should have...
- Take the servo apart by removing the bottom 4 screws and gently slide the cases apart slightly. You don't need to disassemble the servo completely for this procedure, just separate the case about .125" or an eighth of an inch (3mm).
- Now apply a thin bead of silicone or red RTV gasket sealer to take the place of the janky O-Rings. You can use any color silicone you wish, I like to use white so I can see if I missed any spots. Apply this sparingly, you don't need to bust out the caulk-gun for this.
- Allow the silicone to setup for about 1/2 hour and then reassemble the case being sure not to over tighten the screws and blow out the bottom of the servo case...
After reassembly you can cut off the excess silicone with a razorblade or an X-Acto blade.
For the ultimate seal, wrap the outside of the servo seals with 2 layers of electrical tape, that will seal it up quite well. You can also blob a spot of silicone, grease, Vaseline or any other water repellent substance on the servo spline under the horn. Then cover everything with a shot of "Camp Dry", that's how I used to seal up my servos back in the old days.
I can't believe this has to be done to a "Premium Servo" I haven't done this since back in the 80's when there was no such thing as a waterproof/resistant servo. As far as I am concerned, this is something I should NOT have to do on a 125 dollar servo! I don't have to do this with my other name-brand servos!
C'mon Hitec, get with the program.
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