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Old 01-29-2007, 06:22 AM   #1
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Default 1/8th Buggy SERVO ADVICE

A few questions on servo selection...

For my steering servo should I go with...
105oz. Torque, .08sec (JR Z8800S Digital)
OR
188oz. Torque, .15sec (JR Z8800T Digital)

For my throttle/brake sevo should I go with...
105oz. Torque, .08sec (JR Z8800S Digital)
OR
85oz. Torque, .15sec (JR Z590)

Thanks.
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Old 01-29-2007, 06:39 AM   #2
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From those choices, i would go with the 188oz. Torque, .15sec (JR Z8800T Digital) for the steering and the 105oz. Torque, .08sec (JR Z8800S Digital) for the throttle.
The Z8800T may be a little slower than the Z8800S, but the 105oz of torque is really right on the edge of the bare minimum torque you want for 1/8th buggy steering. So in this case I personally would give up a little steering speed for power.

ON the throttle, while you don't need a TON of torque, you want the fastest that you can get. So that Z8800S would be ideal. Just make sure that you set your endpoints correctly so the servo doesn't put excessive pressure on the carb while at idle and full throttle.
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Old 01-29-2007, 12:04 PM   #3
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IMHO I would go with digital. I personally have had issues with running digital and analog together. Could just me.
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Old 01-29-2007, 12:32 PM   #4
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there a reason you aren't going to use the ace digitals ??

Best servos out there in my opinion

Extremely good value too !!
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Old 01-29-2007, 01:24 PM   #5
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I have run the Ace, Hitec, and JR servo's. For me, the JR's are the way to go. The 9000 series is the way I went. 9000t for steering (320in/oz at 0.15 sec) and the 9000s for throttle(128in/oz at 0.06 sec)


320in/oz may seem like alot and the 0.15 may seem slow but it turns out to be just as fast when you watch one turn the wheels right next to some of the other guy's faster servo's. And the customer service I have had from JR in the past has been excellent. My personal experience with Hitec has really been hit or miss, and non existant from Ace.

These are my opinions, so please take them as an opinion. Other's people have had different experiences.
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Old 01-29-2007, 01:47 PM   #6
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Currently I have an MBX5 and have an Z8800T for steering and a Z590 for throttle/brake.
Previously I had a Mayhem and used a JR Z650 (142/.17) for steering and a Z590 for throttle/brake.
I have never had a problem using one digital and one analog servo.

I am looking at replacing the MBX5 this year and deciding what gear to put in my new ride. As you can tell, I am a JR servo guy and I do feel that the Z8800T was a beeter choice than the Z650 for steering. But I am curious as to if it is necessary to have digital servos. I will probably stick with the Z8800T (188/.15 digital) servo for my steering, but may go with a Z4800S (102/.11 analog) for throttle/brake.
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Old 01-29-2007, 01:57 PM   #7
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Quote:
Originally Posted by slakr
I have never had a problem using one digital and one analog servo.
What kind of radio are you using? Anything that uses a high speed setting with not agree with analog servos.
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Old 01-29-2007, 02:03 PM   #8
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there are some isues with the eight and its linkage right now. they have pulled all the rtr's from the shelf about two weeks ago to correct it and it has been eating steering and throttle servos like fuel. the 590 you used in your other car will not last a day in the eight. make absolutely certain you take the time to find your local losi pro and let him help you set up your linkages. i hate to see you go through two 60 to 120 dollar servos right off the bat. find a good used if you need to save money for a 358 or 360 airtronics for your throttle and a 360 for steering.

also for the guy who said his .15 is just as fast as anyone elses steering servo. are you kidding, you want us to beleive that you and your race buddy's can stand there with the naked eye and your hand speed and tell us you can see no difference in your steering time. to start with those speed ratings are not how long it takes to turn the wheels it is a reaction time to the input for the transmitter to the reciever to the servo. when you turn the wheel it takes your servo .15milliseconds to react. not to turn the wheels. also milliseconds is what you use to measure the blink of and eye. and you and your buddy can see a .06millisecond difference. i doubt it, since that is faster than you can blink. not picking on you just educating.
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Old 01-29-2007, 03:03 PM   #9
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I would've suggested a DZ8450 from JR, but the gears stripped so easily in my 8ight (both steering\throttle), I just couldn't deal with it anymore. I use JR's Z9000 servos, a high torque one for steering and a high speed one for throttle, and I've had no problems with them after a club race\weekend long race.
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Old 01-29-2007, 03:25 PM   #10
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Reaction time or whathave you. Throw a servo at 0.06 into a vehicle. Then throw a servo at 0.15 into the sme vehicle setup and watch the servo's side b side. Then swap the vehicles they are in, just so you know you are seeing it right. You will notice a difference. Most of the speed difference we were seeing was an overpowered servo reacting quicker, under force, than another torque servo. That's all.

I have done it and seen it with my own eye's. Just someting to think about trying, I don't really care if you beleive me.
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Old 01-29-2007, 03:53 PM   #11
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Thats exactly what i said. once the servos start moving they are all the same in speed. those reaction numbers are from the transmitter to the servo. not the speed of the servo itself. maybe i didn't write it clearly enough the first time.
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Old 01-29-2007, 03:56 PM   #12
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We are not saying the same thing. We obviously have a difference of opinions though.
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Old 01-29-2007, 04:08 PM   #13
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Ok one more time you are right. the actual movement of the servos are the same.
you say you steering servo is a .15 speed. that speed is how long it take for the servo to react to you turning the wheel on your radio. a servo that is .08 speed is how long that one takes to react to you turning the wheel. NOT HOW LONG IT TAKES THE SERVO MOTOR TO THROW ONE SIDE OR THE OTHER. THOSE SPEEDS ARE THE SAME AS LIKE THE ELECTRIC MOTORS YOU RUN IN YOU CARS, THERE ARE LIKE 30 AFTERMARKET MOTORS OUT THERE YET THERE ARE ONLY THREE COMPANIES THA ACTUALLY MANUFACTURE THE MOTORS. the same is the same in the motor inside the servo's the are jsut a few manufacturers. that is why once they start to move they are the same speed. the way the reaction gets faster is in the motherboard in the servo in what microprocessor is used to get it read the signal faster and then put that to use in turning the motor.

It is very simple the reaction of any and servos is only how long it takes to react to radio input not the actual speed of its movement. after this i give up.
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Old 01-29-2007, 04:33 PM   #14
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There's only a handfull of companies making TV's so they must all be the same too, right? If that really was the case, none would last any longer, provide any better picture, any better sound, draw anymore or less power, etc...


I'm not denying the fact that the spec's are for initial reaction. Re-read what I posted and actually think about it before you post again.

Now that I'm done with Wingnut, run what you are comfortable running. I look for a throttle servo that's fairly quick but is around 100in/oz. That way you don't need a super strong throttle return spring.

For steering, I generally go for something with a minimum of 200in/oz's and speed isn't as important to me. Generally I do want a somewhat fast servo, but based on what I said above, my steering servo choice of the JR 9000T makes up for it.

I have used Hitec 5925's, 5945's, 311's, 925's, 945's, 625's, and 645's.
Ace 1015's I think they were
JR 270's, 590's, 650's, 9000T's and 9000S's.
KO 2413's

So far my favourite servo's are the JR 9000's and the KO's. Smoothest and longest lastig servo's for me have been these two brands by far. Everyone will have different experiences though.
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Old 01-29-2007, 05:43 PM   #15
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i was only trying to put it in away for you to understand. not for you to respond with go back read it again and think about what i said. i did read it and think about it. and your still on the whole thing that the reaction times is how long it takes for full steering lock and its not.

Last edited by Aaron Waldron; 01-29-2007 at 07:19 PM.
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