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Old 08-10-2009, 10:11 AM   #1
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Default 8IGHT-T 1.0 throttle/brake servo issues

I'm not sure where to find previous discussions on this topic, so I'll start fresh.
My LOSI 8-IGHT-T 1.0 RTR has eaten it's second throttle servo. The first was the cheesy JR that it came with ,the second was a HI-Tec 645MG that had about 3/4 of a gallon run on it at the track. Pretty hard driving. I made sure I wasn't adjusted to the end stop (about .030 gap on the throttle rod and stop) and I was running my end stop at 85% for throttle and 90% for brake so I wasn't slamming the servo against the internal stops. I thought I had it set up right. The radio tray has the two little orange O'rings under the battery pack to help the tray flex (LOSI bandaid mod they suggested for the 1.0) and when I operated the servo in brake and throttle you could see the tray flex about 1/8 inch . I was told that you want that flex which kinda acts like a servo saver. Well I am not too pleased with the lack of longevity on the servo. I can and will buy another if I can't rebuild this one (the servo doesn't sound like the gears blew, it moves full travel without making and grinding when you move it by hand) I think the circuit board might have cracked or maybe it lost the electrical input from the receiver. I was wondering if you guys have any guidance on this. Maybe tips for the set-up.
BTW I am running a Hi-Tec 985 MG for my steering
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Old 08-10-2009, 11:28 AM   #2
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servos are not cheap to produce apparently or manufactuers would sell them all for $5 each. when starting out to join a servo learning associastion is normal. even some of the over $100 servos i like using...they also need serviced once a year(and that takes a months alone). hitech 59XX or 79XX or some of the Ko propo servos are some of the stronger longer lasting servos around. and i use neither often. dont cheap out on servos unless you dont plan on being serious. if your just going through a phase in rcn then burn as many $50 servos up you want. my point is the sooner you spend over $100 on a servo the sooner you will be taken serious and sooner you will be able to worry about other things that wear in your cars. please dont take offense, this is what i was told....
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Old 08-10-2009, 11:43 AM   #3
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Quote:
Originally Posted by elkman View Post
I'm not sure where to find previous discussions on this topic, so I'll start fresh.
My LOSI 8-IGHT-T 1.0 RTR has eaten it's second throttle servo. The first was the cheesy JR that it came with ,the second was a HI-Tec 645MG that had about 3/4 of a gallon run on it at the track. Pretty hard driving. I made sure I wasn't adjusted to the end stop (about .030 gap on the throttle rod and stop) and I was running my end stop at 85% for throttle and 90% for brake so I wasn't slamming the servo against the internal stops. I thought I had it set up right. The radio tray has the two little orange O'rings under the battery pack to help the tray flex (LOSI bandaid mod they suggested for the 1.0) and when I operated the servo in brake and throttle you could see the tray flex about 1/8 inch . I was told that you want that flex which kinda acts like a servo saver. Well I am not too pleased with the lack of longevity on the servo. I can and will buy another if I can't rebuild this one (the servo doesn't sound like the gears blew, it moves full travel without making and grinding when you move it by hand) I think the circuit board might have cracked or maybe it lost the electrical input from the receiver. I was wondering if you guys have any guidance on this. Maybe tips for the set-up.
BTW I am running a Hi-Tec 985 MG for my steering

Sorry to hear that, neither one is that good of servos....... but the 1.0 needs to have the rubber orings under the battery tray to rase the rado tray up so the servo dont hit the chassis on impact..... second make sure that your linkage is set up right and EPS is set, that will kill servos in minutes.... or just go but the 2.0 radio tray, i think the fit the 1.0
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Old 08-10-2009, 12:36 PM   #4
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in my 1.0 truggy iv never use orings and never had 1 servo go out. tho epas are a must
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Old 08-10-2009, 12:37 PM   #5
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looks like your epas are prolly ok. id try to get another servo and hope for best
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Old 08-10-2009, 12:38 PM   #6
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Originally Posted by token View Post
Sorry to hear that, neither one is that good of servos....... but the 1.0 needs to have the rubber orings under the battery tray to rase the rado tray up so the servo dont hit the chassis on impact..... second make sure that your linkage is set up right and EPS is set, that will kill servos in minutes.... or just go but the 2.0 radio tray, i think the fit the 1.0
The 2.0 tray will bolt right in.. and is a LOAD stronger and holds both servos much better.. the 1.0 only had a single side of plastic on the throttle servo.. the 2.0 has the servo surrounded by plastic...

P.S get the 2.0 linkages as well if upgrading the 2.0 radiotray
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Old 08-10-2009, 12:42 PM   #7
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Originally Posted by 8&stuff View Post
in my 1.0 truggy iv never use orings and never had 1 servo go out. tho epas are a must
http://www.losi.com/ProdInfo/Files/8...ndum_LoRes.pdf

They would not tell you to do it unless it is important - use the orings - follow the instruction

I have known, read about, seen way to many people losing &100 servos because of this problem and that why Losi took the time to find the problem and fix it - because off the hundreds of people complaining about the servo issue in the 1.0
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Old 08-10-2009, 01:02 PM   #8
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Losi isn't the only car with this problem. They all have flex tuned chassis now and they all want everything mounted as low as possible. Problem is you can't have both. If that chassis bends and smacks that servo, its good night radio gear.

My RC8 had a similar problem. I put a couple plastic washers (from Ace)under the throttle servo to raise it 1/8th of an inch. I was impressed that my Xray allready has about 1/4" of clearence.



So what I've learned from my pile of smoked servos that need sent back for repairs:

1. Allways mount your servos with good chassis clearance, especially the throttle servo as thats where most chassis flex occurs.

2. Epa

3. Increasing your epa for more brake deosn't allways work. Your brakes should stop the car with a reasonable amount of force, but your servo shouldn't have to pull too hard.

Sometimes you need to clean or replace rotors/pads to maintain braking performance. Cranking up the epa to get more pull only overloads the servo. If the pads/rotor are filthey or worn all the pulling in the world won't stop the car, still need friction. Using old AE rotors killed one of my servos.

4. Make sure your linkage can't jam when on the throttle. my Rc8's brake wires would shove on the fuel tank, Too long, and that would make the normally easy task of holding the throttle open real hard on my servo.

5. Use the rubber thingys that come with the servo.

6. Alot of servos only last 1 race season anyway. (repairs are cheap if you've got spares or some down time) You can only case a big jump so many times......

7. 7955 or 7950
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Old 08-10-2009, 01:02 PM   #9
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Also, I use the rubber groments for my throttle servos. Checking to see if the linkage is paralell to the ground and the linkage turns toward the gas tank when at brake, and towards the engine when at WOT. So that means at 50% throttle the linkage should be straight. Thats how I adjust it and along with 3 o rings (yes 3) and the groments I have not burnt a throttle servo yet.
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Old 08-10-2009, 02:29 PM   #10
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Quote:
Originally Posted by JRTinphilly View Post
The 2.0 tray will bolt right in.. and is a LOAD stronger and holds both servos much better.. the 1.0 only had a single side of plastic on the throttle servo.. the 2.0 has the servo surrounded by plastic...

P.S get the 2.0 linkages as well if upgrading the 2.0 radiotray

x2 problem solved. and is what i do...


Quote:
Originally Posted by token View Post
http://www.losi.com/ProdInfo/Files/8...ndum_LoRes.pdf

They would not tell you to do it unless it is important - use the orings - follow the instruction

I have known, read about, seen way to many people losing &100 servos because of this problem and that why Losi took the time to find the problem and fix it - because off the hundreds of people complaining about the servo issue in the 1.0

after a day of use my o rings are shot lol. i tried 2, 3 and then just try to find a po on those orings. i like using all losi too. i guess if have to call horizon and tell them to keep'em coming cause they dont last. bunch up a rubber band...that works better than rubber o rings

on the jr 9100 servos i run in my truggy with more than 5 gallons they are fine but those orings dont last. id just get the 2.0 tray and go
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