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Old 12-11-2014, 09:37 AM   #8311
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Let's talk more about this faster servo thing.

I have a fast servo in one of my cars. It could turn the wheels so fast that the car couldn't respond fast enough and it would understeer.

I slowed down the servo on my radio and handling seemed to improve.

What's going on there?
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Old 12-11-2014, 09:40 AM   #8312
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Originally Posted by .crispy View Post
Let's talk more about this faster servo thing.

I have a fast servo in one of my cars. It could turn the wheels so fast that the car couldn't respond fast enough and it would understeer.

I slowed down the servo on my radio and handling seemed to improve.

What's going on there?
My guess is that the issue is a lack of grip with the HPI VTA tires.
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Old 12-11-2014, 09:52 AM   #8313
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Originally Posted by 18to88 View Post
They are all nice guys....and fast......
See If I let one of the fast guys drive my car and he says dude wtf......
Then i am going to be tore up.......
If he says your setup is good its you......then tore up again........
Is that worse than being 3 seconds a lap off the pace? Have someone drive the car, preferably someone good who drives that same chassis but someone good. It may be you, it may be the car, but probably both! IF someone there has a motorlyser or a Gforce motor checker, have them check the timing of the motor. The timing label is not a reliable way to set the timing on a BOSS as it can be way off (my BOSS at 45 degrees by the label was actually 58). My motor never ran well until I got the timing set to a real 45 degrees, now its very competitive. Generally the FDR will be between 3.6 and 4.0. I'm running 3.61 but I run on large outdoor tracks.

I have digital servos in my cars, because they center better than the older analog ones. While faster, I slow them down to match my driving style.

VTA tires are difficult to break in, but once they are broken in the seem to work very well. Here is what I do, sand of any molding seam, wash with winter green, break in using Paul Lemieux tire break in process, wash again with winter green, run them for a few minutes on my concrete driveway, wash again with simple green, coat them with Paragon Black and put them in a baggie 24 hours. Usually they are ready to race out of the bag.

Last edited by John Wallace2; 12-11-2014 at 10:03 AM.
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Old 12-11-2014, 09:55 AM   #8314
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Originally Posted by .crispy View Post
Let's talk more about this faster servo thing.

I have a fast servo in one of my cars. It could turn the wheels so fast that the car couldn't respond fast enough and it would understeer.

I slowed down the servo on my radio and handling seemed to improve.

What's going on there?

My guess is too much steering input is being requested in too short a timeframe. Making a gentler arc into turns (which loads the suspension a lot more gradually) would probably alleviate the problem w/o having to slow down the servo.

The biggest advantage I see to using faster servos is having the capability of making corrections mid-corner if needed. Otherwise, there's no real difference when comparing servos on speed alone.
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Old 12-11-2014, 11:29 AM   #8315
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Originally Posted by 18to88 View Post
So myself and buddy started VTA.....I have raced 1/8 scale nitro dirt oval for 3 years and I thought I was pretty good. My buddy has raced off an on for years and is way better than me.
We both buy TC 6.1's and were off.........we think......
We have been to the track for 4 race days. We always get there early so we can practice.
Bottom line is we suck....bad.....like I am around 3 sometimes 4 seconds off the pace,he is better maybe 2. We thought this class was for beginners I guess not.
So how do we improve? I don't want to bother the other racers.
Or am I expecting too much to soon?
We are old guys also....lol
Simple answer to this dilemma - develop a chassis setup that doesn't scrub speed in turns, maintains good grip, yet doesn't create too much grip that would slow the car on the track. The other thing to bear in mind - MANY VTA drivers are experienced TC racers, and have a deeper understanding of TC setup that allows them to lap the track a little faster. My advice - find a good VTA setup on the Associated site, build your car to that setup, and practice as often as you can. Chances are, you'll start to improve as your track time increases, but at least you'll be able to eliminate setup from the equation.
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Old 12-11-2014, 01:53 PM   #8316
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Originally Posted by .crispy View Post
Let's talk more about this faster servo thing.

I have a fast servo in one of my cars. It could turn the wheels so fast that the car couldn't respond fast enough and it would understeer.

I slowed down the servo on my radio and handling seemed to improve.

What's going on there?
What I have seen is exactly that. The faster the servo the more Push in the start of the turn. Overheating the tires and just loosing speed.


I have taken a very fast servo and compared it back to back with a slower one. (Actually used 3 servos) .05, .1 and .15

Now the least tire heat from any servo was the .15 but lap times were about .2-.4s slower all over the range. and adjusting to the slowness was hard.

The fastest Servo had the slowest lap times on average. but if I slowed down turning the wheel (with a good 2.4 GHz Radio) I got the times back up to the fastest but that is hard work.

Easiest to drive and fastest Lap times was the .1 servo. Will have to test the in-between speeds (as my radio does not have servo speed).

Best Servo is the one that is Reliable, Centers Perfectly and is within your budget.

I have started to Use the Cheap Solar Servos and they are mid range in speed and Cheap for a low Profile Servo (~$15).

You will have to test for yourself and just about every brand has a good servo for your needs.


Also Watch out for Gear slop in most of the cheaper Servos. I have found the Solar ones that are metal Geared are perfect.
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Old 12-11-2014, 02:33 PM   #8317
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Quote:
Let's talk more about this faster servo thing.

I have a fast servo in one of my cars. It could turn the wheels so fast that the car couldn't respond fast enough and it would understeer.

I slowed down the servo on my radio and handling seemed to improve.

What's going on there?
I can tell you for my preference, I have always used slower servos when I didn't have a radio that would control speed, and almost never run a servo higher than about 60% speed (using Futaba 9650's)

I also play with turn in speed as well as return speed.

I also use the radio end points to limit how far the servo can turn - because I have a bad habit of being a LOCK Turner (I turn the radio knob fully to the lock in the corners) and set it to have just a tad more steering than I'll actually need w/o having too much)

Then, I use the D/R 2 button, or Oh Shxt Button (on my Futaba 3pk) with 100% steering set if/when I'm in a situation where I need to get full steering.

...I wish FUTABA had a button like this for Throttle, where I could set my up front throttle to say 85-90%, and mid way through a race I could bump it to 100% as the charge drops down a bit!
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Old 12-11-2014, 04:45 PM   #8318
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There' also the issue of SERVO SPEED VS FRAME RATE SPEED, two different measurements, two different effects.

Last edited by regets ama; 12-11-2014 at 08:03 PM.
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Old 12-11-2014, 04:59 PM   #8319
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There' also the issue of SERVO SPEED VS FRAME RATE SPEED, two different measurements, two different affects.
"Effects" you tool!

You still haven't effectively explained to me how frame rate affects my steering?

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Old 12-11-2014, 05:32 PM   #8320
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Old 12-11-2014, 05:33 PM   #8321
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Old 12-11-2014, 08:09 PM   #8322
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Originally Posted by .crispy View Post
"Effects" you tool!

You still haven't effectively explained to me how frame rate affects my steering?

There's some engineers out there who could best define it, but for me, in laymans term:
Let's just say servo speed is how fast it will move the servo arm from point A to point B
while frame rate is how fast the transmitter talks to the receiver AFECTing the servo movement.
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Old 12-11-2014, 08:23 PM   #8323
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Originally Posted by regets ama View Post
There's some engineers out there who could best define it, but for me, in laymans term:
Let's just say servo speed is how fast it will move the servo arm from point A to point B
while frame rate is how fast the transmitter talks to the receiver AFECTing the servo movement.
So close...

Darn "F"...

I'll take your word for it. See you tomorrow.
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Old 12-11-2014, 08:55 PM   #8324
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Old 12-11-2014, 10:09 PM   #8325
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Guys- Thunder Jam VII is going to be Jan 11. 2015 @ Thunder RC Raceway (Home of the USVTA Southern Nationals) in Nashville. We will be running the "New Snowbirds layout" Perfect warm up race for the 'birds'. Please check out the thread in the Tennessee section. Any questions please feel free to ahoot me a pm.
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