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Old 05-04-2009, 10:36 PM   #1
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Default Servos And Physics

I was thinking about this today and wanted to see if there was any validity to this thought.

Most people run two different types of servos one for throttle/break and a diffrent one for steering.

Obviously more torque for sterring is used and more speed is used for throttle/break in general

If you used the exact same servo for both would it make sense that you would have more control over the buggy. The reason behind this thought is if you have a higher speed on the throttle but a lower speed with more torque on the steering then you are not in unison while driving.

If the same speeds were being used for both servos physics tell you that you are controling the buggy at the same rate while you are pulling the trigger and steering at the exact same time.

Does this make any sense??????????????
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Old 05-04-2009, 10:44 PM   #2
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I think that the theory could make some sense, but the problem lies in 95% of racers hand to eye coordination. The difference between .10 and .13 is not able to be percieved by many...if not most racers, especially on track. If the difference in the times were greater, say .25 to .07 then it might have a greater effect.
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Old 05-05-2009, 05:06 AM   #3
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I use the same servo on both steering and throttle.

1. I can't tell the difference between .010 and .013 in the speed area.
2. I always have the right back up servo whether steering or throttle servo dies.

For those who say I have to much torque on my throttle. Well I say this if you set your EPA right. The servo never pulls the carb to it's complete limit nor does it torque down on the brakes. Not to mention I drive Losi 1.0's who are supposedly notorious for killing throttle servo's. I have never had 1 die have seen them die before however. You know what I could always trace it back to user error. Linkage binding or EPA's set incorrectly.
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Old 05-05-2009, 07:17 AM   #4
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I don't think it matters. You are using two different hands and they get use to the controls independently. Not to mention there is nothing "in unison " about brake/throttle and steering.
Just my opinion.
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Old 05-05-2009, 07:25 AM   #5
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There's nothing to gain by having them the same imo. The reason people use two different servos are that they are doing two very different jobs. I'm a big believer in speed on the throttle/brakes, steering too but the steering servo needs at least a certain amount of torque. You can have both max speed and torque if you spend enough $$.
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Old 05-05-2009, 07:57 AM   #6
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I was using a 9100s for the throttle and it blew up on me during practice on raceday. All I had to use was a 9100t and I could definatly tell it was slower. I replaced it with a hitec rlthays rated at .10 and can't say there is a huge difference but after having a fast throttle and strong steering 300+ oz of torque I can't go back. In theory ok but reality is faster and stronger are both desireable by competitive racers.
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Old 05-05-2009, 08:17 AM   #7
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I treat my throttle and steering differently from each other. My steering i gently turn and hardly ever turn the knob all the way, my throttle on the other hand gets hammered, going from 0-whatever as fast as i can.
I run the same servo's because i wouldn't notice the small speed rating
I want a lot of torque on my throttle to protect it from me.
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Old 05-05-2009, 08:18 AM   #8
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Which law(s) of physics are you considering?

The servos are performing two different tasks and there are as many variables to consider as there are forces in play.

With enough torque, the steering response will mostly be consistent no matter which forces are working against them. This doesn't account for traction, just that the steering mechanism will be consistent.

Acceleration and braking response can't be compared to steering response. The most noticeable factor to consider is that the throttle action of the servo is actuating another complex machine: the engine. The acceleration response can't keep up with our throttle fingers for a number of reasons. There are numerous other forces acting outside of the servo control to list here.
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Old 05-05-2009, 08:47 AM   #9
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When I drive my real 1:1 car.....I can mash the throttle to the floor a whole lot quicker than I can turn the steering wheel from stop to stop, with no negative repercussions that I can tell. I think you're confusing response time with transit speed.
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Old 05-05-2009, 09:18 AM   #10
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i like high speed on both..but you gotta have atleast 200 oz of tourqe for steering...The throttle brake needs to be fast because its always traveling from one extreme to the other and it needs to do it efficantly...constantly from full throttle to full brake in a split second...

I think steering needs to be fast to but maybe not killer fast... .10-.13 is great..the only issues with a fast steering servo is it can make the steering seem twitchy
The servo for steering has to travel a great distance from one end to other on steering (around 180 degrees left to right were the throttle servo bairly moves half that )and it has to be quick to get there so your not under steering the car...

This all can be a waste if the servo saver isnt set up correctly too and unloads to easy!
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Old 05-05-2009, 01:48 PM   #11
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If you have different rate servo's or the same rate servo's in your car, does it really matter after you make your adjustments on your radio? I run the same servo in both throttle/brake and steering in my truggy, I don't think that they are running the same speed when I get done setting the limits/transits on my transmitter.
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Old 05-05-2009, 02:23 PM   #12
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I run JR 9100s on both and I'm in the boat of both being the same, but I think it's more personal than physics. Now I would bet that if you run one digital and one analog you would feel a differance.
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Old 05-05-2009, 02:53 PM   #13
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Quote:
Originally Posted by jrwoodchuck View Post
I run JR 9100s on both and I'm in the boat of both being the same, but I think it's more personal than physics. Now I would bet that if you run one digital and one analog you would feel a differance.
I tried mixing digital and analog servos once, the Spektrum receiver did not like it at all!! Hey Woodchuck, what happened to the give Jazz crap thread?
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Old 05-05-2009, 03:07 PM   #14
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I have been running the hitech 7955 TG in both steering and throttle. I recently switched to a 6965 HB for the throttle for more speed and I could tell a difference the way it handled.

I know there are many diffrenct variables to consider, I just thought it was interesting to see what everyones thought was.

I do believe that it would make a big diffrence if a robot was controling the radio, however I think that it may be nearly impossible for your left hand to operate at the same speed as your right hand thus not making much of a diffrerence when it comes to handling.

Going to switch back to the 7955's in both though. I thinks its mental at this point.
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Old 05-05-2009, 03:24 PM   #15
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Quote:
Originally Posted by elcaminosslover View Post
Hey Woodchuck, what happened to the give Jazz crap thread?
He's old, and can't come up with anything funny....
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