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Old 07-28-2005, 02:08 AM   #1
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From the quick question department.....(this may be a tricky one).....

What follows is a cut and paste from the 1/12th forum along with a follow up (it wasn't commented on in that thread).....

"Just got a new JR Z3550 servo and a JR RS310 receiver to go in my 1/12th when it arrives. I hooked it all up with the Esc just to check if it goes and I'm wondering is it normal for this servo to twitch/glitch (make a gear noise, or whatever you want to call it lol)?

The output isn't actually moving much (barely perceptible) but it sure "sounds" like it is.

At the moment servo travel is set to 100% and it does seem to ease off/stop at 70% or less but I just tried my previous (standard size JR 577) servo and not even the slightest sound."

Now add to that.....

I've just noticed the problem with the Z3550 goes away completely if you touch the aerial of the transmitter with your hand.....

Any ideas why and does this point to a problem of another sort?
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Old 07-28-2005, 03:31 AM   #2
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Default Digital

Im not sure but my answer is reffering to that servo being digital so heres my explanation.

Digital servos are much more complicated than your average servo. They are always constantly checking their position and re-centering and thinking alot in basic terms. My guess would be by touching hes interupting it some how thats why it goes quiet. Again this is just a quick stab and im not sure so if anyone out there has the answer plz say so as its got me puzlled to
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Old 07-28-2005, 04:00 AM   #3
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I will take a stab at this even though i'm some what a newbie.

I sound like the new servo has a much more throw (steering range) than your old one. I had a similar problem with my hitech servo a while back. Since 12 scale only need a certain amount of steering. Try to adjust you servo range, on your radio. you might only need 65 or 70 for full throw both left and right. This way when you steer a full right/left. it is only taking the servo to were it need to go. If you have it at 100% and it only needs 65% the servo will be trying to steer in a range that it is being stopped before it hits 100% and there fore placing stress on the servo. sorry about the long post been up too long and still have 6 hours of work to go. (man being up for 24 hours sucks.)

But then again I could be wrong. my .02
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Old 07-28-2005, 05:08 AM   #4
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Default My bad but I should have said.....

this testing is taking palace uninstalled in the car (that only arrived today actually lol).

I understand what you're saying though as on my TC I'm only using 88% of total servo throw.

The Z3550 is digital? There was no mention of that on the website I got it from, I only picked it up because it seemed the ideal model for 1/12th.
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Old 07-28-2005, 06:39 AM   #5
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i agree with dimo i ahve been told by my lhs that digitals always try to self centre and that is what the noise is. it is annoying i agree. if the servo is not digital perhaps [a real stab in the dark] your frame rate is too quick for it and it is not able to read signal quick enough so when you add resistance in the form of your hand it interrupts the signal long enough to make it stop? thats all i can come up with. my 2 cents.
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Old 07-28-2005, 08:01 AM   #6
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Default oi

Quote:
Originally Posted by karndriver
i agree with dimo i ahve been told by my lhs that digitals always try to self centre and that is what the noise is. it is annoying i agree. if the servo is not digital perhaps [a real stab in the dark] your frame rate is too quick for it and it is not able to read signal quick enough so when you add resistance in the form of your hand it interrupts the signal long enough to make it stop? thats all i can come up with. my 2 cents.
oi, thats wat i said lol.....
funny enuf only learnt this in the last month i tried to return a ko dig. servo for warranty as it buzzed..lol , i managed to break it anyway.Got a 9550 coming
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Old 07-28-2005, 01:08 PM   #7
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Okay, here's my stab.

When you switch on the system, your servo is trying to centre itself to your radio's signal (assuming 1500uf) but as the servo steps only at 1502uf and 1498uf, it'll constantly "hunts" from 1502uf to 1498uf.
When you touch the transmtter's antenna, that could have shifted the signal to 1502uf or 1498uf.

Most digital servos have this "problem" due to their super precise deadband and pple think they faulty when they're not.

I bought a whole bunch of Hitec Digital servos because this is the only company with a servo programmer available to consumers.
Now, I am able to define my servos centre, absolute left/right end points, deadband and a whole lot of other parameters not available on the transmitter.
In addition, I'm also able to see the transmitter's signal as received by the receiver as well as the actual BEC output.
...opps ! sorry....beginning to sound like a Hitec advert !
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Old 07-29-2005, 06:28 AM   #8
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I've been using the Hitec HS5925MG for almost a year now and I can't count how many times I've had to explain to a corner worker that the "noise" is ok. What I've found is that you definitely have to turn down your dual rate which will help it to center a little better. If you try to turn the wheels, the noise will increase as the servo tries "harder" to center itself. But if you have the car on the stand and you tap the wheel a few times to get the wheels to the actual center, the noise should go away.
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Old 07-30-2005, 09:22 PM   #9
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Quote:
Originally Posted by teamgp
I've been using the Hitec HS5925MG for almost a year now .
I've quite a number of HS5925MG and they're wonderful, but lately I'm replacing most of them with HS6965HB which is cheaper, lighter and because of the Karbonite gears, longer lasting. The 5925MG will wear out after 6 mths of regular usage and develop backlash.
The newer Hitec digitals (With Ti gears) are too expansive, they're about the same pricing bracket as KOs and Futabas.
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Old 07-31-2005, 07:15 PM   #10
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I have the same kind of noise with my Futaba S9451 Digital Servo on my touring car, and what everyone is saying is right, it's just trying to center itself. However, it seems to stop making the noise if I just inch the car forward with a little bit of throttle, and I don't know why, but it does.
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Old 07-31-2005, 07:35 PM   #11
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Post It all makes sense.....

Quote:
Originally Posted by TeamPink91
I have the same kind of noise with my Futaba S9451 Digital Servo on my touring car, and what everyone is saying is right, it's just trying to center itself. However, it seems to stop making the noise if I just inch the car forward with a little bit of throttle, and I don't know why, but it does.
if I had a digital servo, but I can find nothing that says the JR Z3550 is digital (even on Horizon Hobbies own website)? All good if it is of course then I know where I'm at.

In the second post Dimo writes: "Im not sure but my answer is reffering to that servo being digital so heres my explanation."
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Old 07-31-2005, 10:25 PM   #12
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Quote:
Originally Posted by Mabuchi540
if I had a digital servo, but I can find nothing that says the JR Z3550 is digital (even on Horizon Hobbies own website)? All good if it is of course then I know where I'm at.

In the second post Dimo writes: "Im not sure but my answer is reffering to that servo being digital so heres my explanation."

yes my post was refferinh to wether the servo was digital... and if it is for a 12th scale im sure it would be digital...
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