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Tamiya F104 Pro!

Old 10-21-2009, 11:29 PM
  #1396  
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Originally Posted by zpmhinojosa View Post
I just got this servo. I'm a hopeful, I'm gonna do the hand work and switch back the the original 104 front, because this didn't happen hours before I made the switch. Man, I have alot to learn!
Here it is, did the work, no change! SO THANKS TO THE SERVO GUYS!!! You were right. Servo is dust. Unless, it can be re-built?



Now I put in a futaba, it's old, but no issues. So, now I might put back the 103 front and re-test it...
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Old 10-22-2009, 05:15 AM
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I have a dx3s and I run 35% expo in the steering. This is the single best adjustment you can make for the car. It was the difference btwn my 103 and 104. 104 is faster now that is dialed. If their is any question as to which car is better..have you seen DJ run his f104?
Expo will smooth out the car so you can push it harder.
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Old 10-22-2009, 07:07 AM
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Originally Posted by fat500 View Post
I have a dx3s and I run 35% expo in the steering. This is the single best adjustment you can make for the car. It was the difference btwn my 103 and 104. 104 is faster now that is dialed. If their is any question as to which car is better..have you seen DJ run his f104?
Expo will smooth out the car so you can push it harder.
Wow, -35%?!?! Although, that's what I thought would need to be done for the F104 and it's chassis design. I'm putting my F104 on the track this weekend for the first time so steering exponential was something I was planning to play around with. I normally don't like going beyond -20% for 1:12 cause sometimes you can get dialed out too if you rely too much on the radio settings, but again with the F104's chassis design negative steering exp is definitely a must.
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Old 10-22-2009, 12:05 PM
  #1399  
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Originally Posted by fat500 View Post
I have a dx3s and I run 35% expo in the steering. This is the single best adjustment you can make for the car. It was the difference btwn my 103 and 104. 104 is faster now that is dialed. If their is any question as to which car is better..have you seen DJ run his f104?
Expo will smooth out the car so you can push it harder.
Hey fat,

Here's what's goin on with me controller wise, it's a Traxxxas 27mhz am digital Top Qualifier, so it's hardly fancy. The other issue is I'm still learning the termonology (newb). Don't take this wrong, but I wish I knew what you guys were talkin about. I want to learn this $#!^. This is why I come here, to seek R/C knowledge from people who know what the're talkin about. I'm sure I'm about to get schooled right abouuuuut now!
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Old 10-22-2009, 02:05 PM
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Originally Posted by zpmhinojosa View Post
Hey fat,

Here's what's goin on with me controller wise, it's a Traxxxas 27mhz am digital Top Qualifier, so it's hardly fancy. The other issue is I'm still learning the termonology (newb). Don't take this wrong, but I wish I knew what you guys were talkin about. I want to learn this $#!^. This is why I come here, to seek R/C knowledge from people who know what the're talkin about. I'm sure I'm about to get schooled right abouuuuut now!
It's all god bro. The "exponential" adjustment for the steering servo, in this example, allows you to adjust how far the servo turns in relation to how far you turned the wheel, but the key here is that the servo will turn in a non-linear fashion.

Here's two examples to give you some perspective.

A radio without "expo"...when you turn the wheel 1/2 way, the servo also turns 1/2 way. When you continue turning the wheel to full lock, the servo also continues turning to full lock.


A radio with expo ...in this example of a twitchy F1 car, you'd set the expo to a negative number (-35% for Fat500). When you turn the wheel half way, the servo would turn a bit less than that. For explanations sake, lets say it's equal to that 35%. So the wheel was turned 50%, but the servo only turned 35%. That makes the car steer less, and thus looks and handles less twitchy. But to finish this example you need to continue turning the wheel all the way to full lock at 100%. Since the servo only moved through 35% of it's travel so far, it has to play catch up and move the other 65% in order to meet the wheel at 100% at the same moment in time. The tires still turn the same amount at full lock, but with negative expo, there's no longer a 1:1 corelation between how far your turn the wheel and how far the tires actually turn (until you reach full lock).

Anybody still awake?
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Old 10-22-2009, 02:11 PM
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Originally Posted by zpmhinojosa View Post
Hey fat,

Here's what's goin on with me controller wise, it's a Traxxxas 27mhz am digital Top Qualifier, so it's hardly fancy. The other issue is I'm still learning the termonology (newb). Don't take this wrong, but I wish I knew what you guys were talkin about. I want to learn this $#!^. This is why I come here, to seek R/C knowledge from people who know what the're talkin about. I'm sure I'm about to get schooled right abouuuuut now!
you wont get schooled or flamed unless you ask a really dumb question, or ask the same dumb question more than once.
There aren't many dumb questions, but there are a few
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Old 10-22-2009, 02:13 PM
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Originally Posted by Greg Sharpe View Post
It's all god bro. The "exponential" adjustment for the steering servo, in this example, allows you to adjust how far the servo turns in relation to how far you turned the wheel, but the key here is that the servo will turn in a non-linear fashion.

Here's two examples to give you some perspective.

A radio without "expo"...when you turn the wheel 1/2 way, the servo also turns 1/2 way. When you continue turning the wheel to full lock, the servo also continues turning to full lock.


A radio with expo ...in this example of a twitchy F1 car, you'd set the expo to a negative number (-35% for Fat500). When you turn the wheel half way, the servo would turn a bit less than that. For explanations sake, lets say it's equal to that 35%. So the wheel was turned 50%, but the servo only turned 35%. That makes the car steer less, and thus looks and handles less twitchy. But to finish this example you need to continue turning the wheel all the way to full lock at 100%. Since the servo only moved through 35% of it's travel so far, it has to play catch up and move the other 65% in order to meet the wheel at 100% at the same moment in time. The tires still turn the same amount at full lock, but with negative expo, there's no longer a 1:1 corelation between how far your turn the wheel and how far the tires actually turn (until you reach full lock).

Anybody still awake?
im running a KO Helios, and I am trying to figure out which function is like expo.
What you are essentially saying is you are lessening the reaction of the servo versus the input at the wheel
Makes sense to me
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Old 10-22-2009, 02:25 PM
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Originally Posted by BP SHADOW View Post
im running a KO Helios, and I am trying to figure out which function is like expo.
What you are essentially saying is you are lessening the reaction of the servo versus the input at the wheel
Makes sense to me
It would be the ST CURVE function. Use - (negative) number to desensitize the steering.
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Old 10-22-2009, 03:24 PM
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Originally Posted by BP SHADOW View Post
...What you are essentially saying is you are lessening the reaction of the servo versus the input at the wheel..
Yes, but only over the first % of wheel input. The final % of wheel input will be met with an increased reaction from the servo. The end result is that 100% wheel input also equals 100% servo throw. However, you can decide if you want the servo to be less sensitive initially and more sensitive later which is negative exponential -OR- you can choose to make the servo overly sensitive initially and less sensitive later which is positive exponential.

Believe it or not, there are instances where positive exponential is useful.
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Old 10-22-2009, 04:32 PM
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Originally Posted by fat500 View Post
I have a dx3s and I run 35% expo in the steering. This is the single best adjustment you can make for the car. It was the difference btwn my 103 and 104. 104 is faster now that is dialed. If their is any question as to which car is better..have you seen DJ run his f104?
Expo will smooth out the car so you can push it harder.
Agree. I am running -15% Expo (DX3s) in my F103R and this helped a LOT with over-corrections and turn-in being much smoother. It wasn't just me!
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Old 10-22-2009, 05:13 PM
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WOW, all those responses are awsome. School's in and I'm takin notes.
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Old 10-22-2009, 05:13 PM
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im running a KO Helios, and I am trying to figure out which function is like expo.
What you are essentially saying is you are lessening the reaction of the servo versus the input at the wheel
Makes sense to me
This link doesn't specifically deal with Servo Exponential, but it does show exponential curves versus linear and cubic. Note the Exponential curve appears less steep at the left and gets steeper as you move to the right. Getting "exponentially" steeper or greater.

http://en.wikipedia.org/wiki/Exponential_growth

That is what servo expo does. Upon initial response, the servo moves less per user input, but to make up for that, it moves more per user input as you get closer to full lock to get to 100%. Setting negative expo really just smooths out (more precisely - deadens) the initial servo response.

You can also use this sort of curve function for throttle response. I set it in my Speed Control (Tekin) but most radios also have this avaialble. It seems to work better for me on the speed control when it comes to throttle expo. Looks like the Helios has a throttle curve setting too.

Believe it or not, BMW has something similar (as an option) for their 1:1 cars. They call it "active steering". Depending on vehicle speed, it takes fewer turns of the steering wheel (or more) to reach full lock.

Last edited by Arthur Burns; 10-22-2009 at 05:24 PM.
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Old 10-22-2009, 07:15 PM
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Default f103 or f104

WTB one of these chassis if anyone has a extra.Thanks
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Old 10-22-2009, 08:42 PM
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I see that Orion Rocket packs / stick type batteries fit.

Can someone recommend any other lipo packs that fit and are cheaper. Will a non - hard case pack fit? www.Hobbycity.com has some 7.4v 4000mah packs fairly cheap.
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Old 10-23-2009, 10:31 AM
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Originally Posted by BP SHADOW View Post
you wont get schooled or flamed unless you ask a really dumb question, or ask the same dumb question more than once.
There aren't many dumb questions, but there are a few
I have a few questions:
  • When I change to a red shock spring, what gear ratio should I use?
  • If I run with a lighter weight shock oil, do I have to add lead weight to make up the difference?
  • When I turn my steering wheel to the left, my car goes forward. When I turn it to the right, it does nothing. I'm trying go 170mph so any help would be appreciated.
  • I painted a body from the inside and put stickers on it but the finish is still dull. How do you get yours to be so shiny?
  • If I use velcro to hold my battery in, what gear ratio should I use?

Thanks in advance.
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