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cortesoft
08-24-2011, 01:51 AM
I have had my 120 SR for a while now, and it has worked great. Recently, however, the elevator controls seem to have stopped working. I noticed it while flying one day when suddenly I couldn't move forward or backwards anymore. There is no noticeable damage, but I can see when I move the elevator controls nothing happens. There is a slight electronic hum when I move the elevator controls, like something is trying to move, but nothing happens. All other controls work normally.

I am thinking I will probably have to take it into the shop, but I figured I would ask here first to see if anyone has any ideas I can check before taking it in. Thanks in advance!

Daniel

CarCrazy
08-24-2011, 01:58 AM
Check the gears on that servo. If they are all good then I would try to move the servo gear by hand very very very carefully. If that doesn't work then the servo might have gone out on you.

cortesoft
08-24-2011, 02:34 AM
The gears look fine. I tried spinning them by hand.. it spins ok, except it seems to get caught on something somewhere a bit in the rotation... and then with just a bit more force it gets through it and spins again until it catches a bit on the next rotation. It does this every rotation. The arm does move the whole range of the servo though. The other, working, servo does not do this.

This is leading me to believe there is something physically catching on the gear or rod. I am tempted to try to remove the larger gear and see if the servo can spin freely. Do you think this is a good idea?

Pfloyd
08-24-2011, 05:05 AM
You most likely got dirt on the gears...use a stiff toothbrush and clean the large and small gears.

timatworksg
08-24-2011, 07:24 AM
Yes try cleaning out the gears with a toothbrush dry. Don't force it anymore in case a tooth breaks or whatever is stuck there will cause further damage.

Any hard landings recently? If yours is stock, those skid pegs that go into the fuselage stick out (especially the rear left peg-which handles pitch) and is very close to the gear of the servo. A hard landing will flex the fuselage and that protruding peg can and will hit the gear. If you read through the mods section, you will see it's recommended to file down that protrusion. Unless you use the RKH upgraded fuselage then it's no issue.

Let us know how it goes. If you have a magnifying glass, take a close look at the teeth...see if any are damaged or something is stuck in between or outta shape.

Mr.Firemouth
08-24-2011, 11:26 AM
My buddy had one hang up, over and over again. We replaced the 5 in 1 and it has been great ever since. The micro servo motors can burn out. It is very common on the Ultra Micro planes that Horizon distributes. Because the wires are so small and soldered to the 5 in1 it is just easier to replace the 5in1 altogether.

If your blade is fairly new,(not sure how long a while is,LOL) call Horizon and ask about a warranty or discounted purchase.

Digital Don
08-24-2011, 06:01 PM
"The gears look fine. I tried spinning them by hand.. it spins ok, except it seems to get caught on something somewhere a bit in the rotation... and then with just a bit more force it gets through it and spins again until it catches a bit on the next rotation. It does this every rotation."

I had exactly the same experience with a Champ brick a buddy gave me because of the same problem. Everything looked fine until I put it under a lighted magnifier. Then I could see that one gear tooth was split near the top. A little work with an Xacto knife and everything was again right with the world. I'm still using that brick today in an Albatros.

If you have a magnifier and a good bright light, give it a shot!

Don

Pfloyd
08-24-2011, 06:30 PM
My buddy had one hang up, over and over again. We replaced the 5 in 1 and it has been great ever since. The micro servo motors can burn out. It is very common on the Ultra Micro planes that Horizon distributes. Because the wires are so small and soldered to the 5 in1 it is just easier to replace the 5in1 altogether.

If your blade is fairly new,(not sure how long a while is,LOL) call Horizon and ask about a warranty or discounted purchase.

Just get a new servo and instead of replacing the whole thing, just replace the large gear or small gear and see if that helps. I had a bad tooth on the large gear and it was really hard to see without a powerful magnifying glass.

cortesoft
08-25-2011, 01:08 AM
Wow you guys are exactly right. I looked closely at the larger gear, and sure enough there is a tooth that looks broken. I am going to attempt some surgery and report back to you how it does.

Thanks so much for the help! You guys are awesome.

timatworksg
08-25-2011, 02:35 AM
We will be praying hard for a successful surgery! Drinks are available at the waiting area!

cortesoft
08-26-2011, 02:18 AM
Success!

I got out my Xacto knife and a good light, and got to cutting. At first it wasn't working. I actually stopped 3 or 4 times, waited an hour and then tried again. I was getting better results.. the servo would move partially but still get stuck sometimes.. but then suddenly it was moving freely! I moved the controls around a bunch to make sure it was really good, and then successfully flew around my living room!

Thank you guys so much for your help. This is the second time I have asked for help on here, and both times you guys have been able to show me how to get back in the air. Hopefully someday I can return the favor!