R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 05-15-2008, 03:15 PM   #1
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default servo troubles...

I was just driving my car and it was fine, now all of a sudden the steering servo doesnt want to work.

its an airtronics 94359 servo, and a spektrum sr3000 receiver.

Everything was working fine then I hit a bit of rough terrain and it turned ALL the way to the right, then stopped working.

and theres also a lot of "rocks" in my receiver case? definately something in there rattling around and I dont know what it is, I hope I didnt break something.
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 03:22 PM   #2
Tech Regular
 
buckeye34's Avatar
 
Join Date: Jan 2008
Posts: 274
Trader Rating: 7 (100%+)
Default

sounds like you stripped your steering servo.. take off the servo arm and switch on rx. then operate your steering and listen to the servo. you will probably just here it spinning inside the case...
__________________
mbx5r
v-spec
jp-3 pipe
hitec 5955tg/steering
ko propo 2367/throttle
m-11
buckeye34 is offline   Reply With Quote
Old 05-15-2008, 03:23 PM   #3
Tech Elite
 
jamminnay's Avatar
 
Join Date: Apr 2008
Location: IL
Posts: 2,012
Trader Rating: 10 (100%+)
Send a message via AIM to jamminnay Send a message via MSN to jamminnay
Default

is the light on the reciever lit up? is the servo making any noise at all?
jamminnay is offline   Reply With Quote
Old 05-15-2008, 03:37 PM   #4
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

The light on the receiver is fine, the throttle/break works fine.

Im sure its plugged in all the way, it didnt just fall out of the receiver.

this servo is fairly new and I was not rough AT ALL on it this driving session.

what do you mean by rx?

I have two spektrum dx3.0 remotes, how come when I switch one on it says RVO (I think its a v) and the other remote says MDI.... the remote with RVO gets like twice the range on it...

It seems like my servo COMPLETLY died, or something in my receiver is wrecked, or maybe its the servo cable.

If I have to buy a new steering servo, Im done with rc cars, getting ridiculously expensive now..

Thanks A LOT for the quick replies guys, I gotta try and fix it soon... I told a buddy id have it ready to drive by the time he gets off work!
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 04:19 PM   #5
Tech Regular
 
buckeye34's Avatar
 
Join Date: Jan 2008
Posts: 274
Trader Rating: 7 (100%+)
Default

rx= receiver, it's in the car, what servo wires plug into...just an FYI:


rx=receiver
tx=transmitter
sx=servo
__________________
mbx5r
v-spec
jp-3 pipe
hitec 5955tg/steering
ko propo 2367/throttle
m-11
buckeye34 is offline   Reply With Quote
Old 05-15-2008, 04:24 PM   #6
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by buckeye34 View Post
rx= receiver, it's in the car, what servo wires plug into...just an FYI:


rx=receiver
tx=transmitter
sx=servo
allright, cool, I didnt know that (im new).

and yes mine is in the car, it was running fine then the steering died.

I can turn the steering with my hands, its not locked up or anything, sounds fine when I force it... another thing, is forcing the servos very bad for them? I know its bad, but to what extent? sometimes I have friends come over and they turn the wheels a lot and sometimes I do it by accident, surely we all do.

Thanks
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 05:03 PM   #7
Tech Adept
 
Join Date: Apr 2008
Posts: 208
Trader Rating: 2 (100%+)
Default

its not that bad at all. aslong as you do not force it past the end points. (where the servo normally stops)

servo's are just a bunch of gear sets to change ratio and provide force.

with your servo i doubt you have stripped it,
94359 High torque 160 oz coreless metal geared with 2 bearings.

You need to answer these questions;

Are you batteries charged enough? are you using a nimh pack or just akaline AA batteries?

with the horn removed, when you operate the steering on you controller does the servo move?, make any noise? It should make a gear noise and it should be fairly even through the whole rotation of the servo. (horn = plastic thing the steering connects to ontop of the servo, remove the top screw then the plastic arm by pulling it off)

If the noise is crunchy or not very even you make have stripped a gear. you will not have to buy a new servo as you can rebuild them fairly easily and pretty cheap. You will need to take out the servo and remove the 4 screws at the bottom of the servo. take out the top board gently then take note of the order of the gears you will remove. (take a pic) check for any broken gears then you can go to you LHS and buy the gear sets (or ebay etc) nice and cheap. replace only the gears that are broken and give the case a good blow out.

If the servo is not moving at all you most probably have a wiring issue. carefully check over all your wiring and if you can't see anything wrong i would remove the servo and receiver (rx) and use them outside of the buggy so you can see whats going on. If its still doesn't move outside of your car and you are sure the wiring is ok then swap the servo onto channel 2 on you receiver where the throttle normally goes and operate your throttle finger on your controller. this will make sure you receiver has not lost (broken) that specific channel 1.

If its a new servo I would think its either the wiring or the gear set. both of these can be fixed for very cheap. The gears can be stripped by hitting something that knocks the wheels in 1 direction fairly hard if its a metal geared servo. if its plastic it can happen easily and you should change to metal geared. also having your servo saver set too tight can cause them to strip on crashes...

good luck

ps. are you in australia? if so I am happy to give you a hand over the phone etc..

Last edited by pracy; 05-15-2008 at 05:07 PM. Reason: didn't see what servo he had, adding specs
pracy is offline   Reply With Quote
Old 05-15-2008, 05:09 PM   #8
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

its not that bad at all. aslong as you do not force it past the end points. (where the servo normally stops) OK, THANKS FOR THE INFO, I NEVER GO PAST THE END POINTS, JUST BACK N FORTH A LITTLE

servo's are just a bunch of gear sets to change ratio and provide force.

You need to answer these questions;

with the horn removed, when you operate the steering on you controller does the servo move? NOPE, make any noise? NOPE, I WISH It should make a gear noise and it should be fairly even through the whole rotation of the servo. (horn = plastic thing the steering connects to ontop of the servo, remove the top screw then the plastic arm by pulling it off) IT DOESNT MAKE ANY SOUNDS, I CHANGED RECEIVER (BECAUSE MY OTHER HAD SAND IN IT) AND IT STILL DIDNT MAKE A DIFFERENCE

If the noise is crunchy or not very even you make have stripped a gear. NO NOISES AT ALL you will not have to buy a new servo as you can rebuild them fairly easily and pretty cheap. THATS AWESOME, I HOPE ITS EASY AND CHEAP You will need to take out the servo and remove the 4 screws at the bottom of the servo. take out the top board gently then take note of the order of the gears you will remove. (take a pic) check for any broken gears then you can go to you LHS and buy the gear sets (or ebay etc) nice and cheap. replace only the gears that are broken and give the case a good blow out. AWESOME, THATS A GOOD PLAN, THANK YOU SO MUCH FOR THAT ADVICE.

If the servo is not moving at all you most probably have a wiring issue. carefully check over all your wiring and if you can't see anything wrong i would remove the servo and receiver (rx) and use them outside of the buggy so you can see whats going on. If its still doesn't move outside of your car and you are sure the wiring is ok then swap the servo onto channel 2 on you receiver where the throttle normally goes and operate your throttle finger on your controller. this will make sure you receiver has not lost (broken) that specific channel 1. DAMN THATS A VERY GOOD IDEA, BUT I CHANGED RECEIVERS ALL TOGETHER SO I DONT THINK ITS THAT.

If its a new servo I would think its either the wiring or the gear set. both of these can be fixed for very cheap. The gears can be stripped by hitting something that knocks the wheels in 1 direction fairly hard if its a metal geared servo. if its plastic it can happen easily and you should change to metal geared. also having your servo saver set too tight can cause them to strip on crashes... WOW ALL OF THAT IS DEAD ON, IT DID KINDA OF HAVE A HARD HIT ON IT. AND I DID HAVE THE SCREW TIGHT, NOT TOO TIGHT THOUGH.

good luck

ps. are you in australia? if so I am happy to give you a hand over the phone etc.. NO IM IN CANADA, THANKS FOR THE OFFER THOUGH, NOT MANY WOULD DO THAT...
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 05:23 PM   #9
Tech Elite
 
Join Date: Mar 2008
Location: Erie Pa.
Posts: 3,323
Trader Rating: 19 (100%+)
Default

Not shure if this was said already but the airtronics servos have 1 plastic gear in them to save all the metal gears. Open it up and look at them.
malik is offline   Reply With Quote
Old 05-15-2008, 05:29 PM   #10
Tech Adept
 
Join Date: Apr 2008
Posts: 208
Trader Rating: 2 (100%+)
Default

normally with a stripped gear you can still hear a buzz or hum when you use the servo. if its dead silent its either a wiring issue, a dead control board which will be covered by warranty or flat batteries. these servo's required a bit of power so make sure you check those batts!


check your pm..
pracy is offline   Reply With Quote
Old 05-15-2008, 05:33 PM   #11
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by pracy View Post
normally with a stripped gear you can still hear a buzz or hum when you use the servo. if its dead silent its either a wiring issue, a dead control board which will be covered by warranty or flat batteries. these servo's required a bit of power so make sure you check those batts!


check your pm..
No I dont hear anything when I turn it on, not a single sound no matter what I do, even change reveiver and remote.

its probably a wiring issue, which ill check, or my battery. I dont think its the battery because the throttle one works fine.
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 05:36 PM   #12
Tech Adept
 
Join Date: Apr 2008
Posts: 208
Trader Rating: 2 (100%+)
Default

also a good test is to hold the servo in hand and operate the control. can you feel any movement inside or vibrations?


the servo saver is not the screws you removed to take off the horn (that screw should be tight) its...

if you follow where the plastic part on top of the servo goes, its goes from servo arm, to a linkage rod then on to your steering rack. the right side of you steering rack is the servo saver. it should have a spring on the bottom of that rack and a little adjusting nut you can adjust by finger. the nut should have serated edges so you can get grip on it by finger. hold the servo tight or the linkage rod and then force the wheels to 1 direction. you will notice the servo save splits in half to allow the servo not to break on crashes. if it does not go into 2 peices ( its doesn't break it just goes back together when you return the wheels) when you turn the wheels the servo saver is too tight and you will need to loosen the tension on that spring.

i don't have my buggy with me so i can't take any pics sorry.

what buggy is yours? i will have a look at some pcis of it...
pracy is offline   Reply With Quote
Old 05-15-2008, 05:39 PM   #13
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by pracy View Post
also a good test is to hold the servo in hand and operate the control. can you feel any movement inside or vibrations?


the servo saver is not the screws you removed to take off the horn (that screw should be tight) its...

if you follow where the plastic part on top of the servo goes, its goes from servo arm, to a linkage rod then on to your steering rack. the right side of you steering rack is the servo saver. it should have a spring on the bottom of that rack and a little adjusting nut you can adjust by finger. the nut should have serated edges so you can get grip on it by finger. hold the servo tight or the linkage rod and then force the wheels to 1 direction. you will notice the servo save splits in half to allow the servo not to break on crashes. if it does not go into 2 peices ( its doesn't break it just goes back together when you return the wheels) when you turn the wheels the servo saver is too tight and you will need to loosen the tension on that spring.

i don't have my buggy with me so i can't take any pics sorry.

what buggy is yours? i will have a look at some pcis of it...
Hmmm, I always wondered what a servo saver is, kinda had a feeling that thats what it was, now I know for sure. I dont think it has anything to do with that though.

My buggy is a Mugen mbx5, stock mostly, servo is airtronics 93459
new to rc cars is offline   Reply With Quote
Old 05-15-2008, 05:48 PM   #14
Tech Adept
 
Join Date: Apr 2008
Posts: 208
Trader Rating: 2 (100%+)
Default

ok

what style of batteries are you using? nimh pack or normal batteries?

you are correct in saying if its operating you trottle it should operate you steering as long as you have removed the plastic horn off your servo as the steering rack and wheels add a lot of extra weight on the servo and required more power. even more so if the saver is set too tight or somethign in binding in you steering setup...

next step is to remove the servo and rx and battery pack (only takes 2mins) and operate them outside of the buggy.

I have the mbx5r so i can pictures you easily as ours are the same servo saver etc..

check you have the wiring plugged in in the correct direction, there are not any break or shorts (touching metal). its a major advantage taking the servo out as it corrects any shorts you may have if you sit it on a wood table or something similar...

if none of this working and the wiring is fine and you are sure the gears are fine ( you can hear if they're not) then take it back to you LHS and get a warranty replacement as it must be the control board.

it would not hurt to open the servo up and check the gears but if you holding it in hand and you can't feel a snigle vibration hen you operate your control its not going to be gears it must either be your wiring or the control board.
pracy is offline   Reply With Quote
Old 05-15-2008, 05:52 PM   #15
Tech Regular
 
Join Date: Apr 2008
Posts: 334
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by pracy View Post
ok

what style of batteries are you using? nimh pack or normal batteries?

you are correct in saying if its operating you trottle it should operate you steering as long as you have removed the plastic horn off your servo as the steering rack and wheels add a lot of extra weight on the servo and required more power. even more so if the saver is set too tight or somethign in binding in you steering setup...

next step is to remove the servo and rx and battery pack (only takes 2mins) and operate them outside of the buggy.

I have the mbx5r so i can pictures you easily as ours are the same servo saver etc..

check you have the wiring plugged in in the correct direction, there are not any break or shorts (touching metal). its a major advantage taking the servo out as it corrects any shorts you may have if you sit it on a wood table or something similar...

if none of this working and the wiring is fine and you are sure the gears are fine ( you can hear if they're not) then take it back to you LHS and get a warranty replacement as it must be the control board.

it would not hurt to open the servo up and check the gears but if you holding it in hand and you can't feel a snigle vibration hen you operate your control its not going to be gears it must either be your wiring or the control board.
Nimh pack, 1600 mah.

It has nothing to do with my servo saver... I think.

Its got to be the wiring, it doesnt attempt to move or anything, but I can force it to move so its not jammed up, sounds normal when I force it.

as much as I dont want to take the radio box all apart again.. I will.

Like I said, everything was working fine, Black on the far right, I drove the car for about 5 mins, almost a whole tank, then the steering KIND of cut out... a few seconds later the steering was full right and my car kept going in circles and I couldnt steer out of it.

I will take the servo out now and take a look at the wires, theres a very good chance its that.

ill post in about 10 mins with my status.

Thank you for all the help, my friend gets off work soon! lol
new to rc cars is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine troubles jgtruggy Nitro Off-Road 5 03-22-2008 03:39 PM
engine troubles banabits Rookie Zone 2 10-03-2007 09:51 AM
tt-01 troubles nekmiyevo2 Electric On-Road 21 08-11-2005 06:34 AM
Car troubles? acutts Electric On-Road 6 03-27-2004 05:16 AM
OS TR(P) Troubles Glenn Nitro On-Road 12 08-28-2002 01:38 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 10:47 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net