Steering again, this time its encoder bias resistors and uneven propo

[cyborgzero]

Okay, here is what I figured out:

On all my SEs, I noticed there is two bias resistors inline with the steering encoder pot on the car..

Now, if you replace one of those with a small pot, say a 10k turnpot, you can tune the steering to perfect even propo in each direction and then measure the resistance on the pot once you do that.

Then, you measure the ohms on that post and you can get a 1/8 watt or smaller resistor and replace the crappy one they originally put in there with your properly tuned ohm value.

This is the ONLY way you will ever get even propo. I have three different SEs, all with slightly different boards and encoder setups, and this worked on all of them to get the propo even.

They try to hide the resistors under really small shrinkwrap near the board.. The little rubber black things that make it hard to put the pcb back? Those are the bias resistors...

Changing that resistance value is how they get the propo steps on each side, and they do a quick bang up job on it over at the big chinese factory in the sky.. They consider 2/5 as "good". If you want full 4/4 like they are capable of you will have to change these resistors.

Anyway, try it youll like it.

Then, once you get the steering all taken care of good things happen.

[potentiality]

Oh! Oh! I feel DIAGRAM/parts list ringing in my head wise one!

Umm I have full 6/6 propo steering after doing the "anti-chatter" mod. Only thing is my car will not drive straight anymore. The problem is there is like a "dead spot" on the steering potentiometer where it won't recenter. Basically what I am try to say is you can move the steering left/right a little tiny bit and it doesnt notice it is off center until you move it a little farther....

Is there any way to fix this? It's like the pot is not sensetive enough? You seem pretty knowledgeable in this area.

[potentiality]

You know, I wonder if thats the remote versus a dead zone on the car. Have you noticed after doing that mod that the steering is very sensitive? And at least on my remote, the spring for the wheel has a tiny bit of play in the middle.

Since there is no true dead zone on the wheel, when you go back to neutral, you in fact are still slightly turned because of the lack of centering.

[cyborgzero]

Originally posted by Whatup1049
Umm I have full 6/6 propo steering after doing the "anti-chatter" mod. Only thing is my car will not drive straight anymore. The problem is there is like a "dead spot" on the steering potentiometer where it won't recenter. Basically what I am try to say is you can move the steering left/right a little tiny bit and it doesnt notice it is off center until you move it a little farther....

Is there any way to fix this? It's like the pot is not sensetive enough? You seem pretty knowledgeable in this area.

Well, thats the thing, if you do the *anti-chatter* mod it will never recenter.

Its basically like this: you can either have absolutely no chatter but no recentering and 6/6 propo, OR you can have only a teeny bit of chatter, decent recentering, and 4/4 propo.

Its all up to you.

I really have to delve into this a bit further, since there has GOT to be a way to have both AND have a decently sharp turning radius.. The stock turning radius is really weak.

Rob

[cyborgzero]

Originally posted by potentiality
You know, I wonder if thats the remote versus a dead zone on the car. Have you noticed after doing that mod that the steering is very sensitive? And at least on my remote, the spring for the wheel has a tiny bit of play in the middle.

Since there is no true dead zone on the wheel, when you go back to neutral, you in fact are still slightly turned because of the lack of centering.

Right.. I am experimenting right now with using the controller to set a null point by using back to back diodes to set a dead spot on the controller.

I will get back to you all on this soon.

Rob

[potentiality]

Probably isn't said enough cyborg, but you rock! Thanks for investigating.

[ph2t]

I rarely post on this forum these days but I gotta say cyborg that you definately are pretty cool with this techo stuff man. Your solution for the steering looks to be far more superior than cutting wires and stuff that the other steering fixes entail. Great work dude. I myslef don't mod my SE too much since I only have the one. (one of the problems with living in Aus). Hope you are going well with figuring out the mosfet mod on the drivetrain as well.


cheers,

ph2t.

Cyborg I think I have figured out why it doesn't recenter anymore and the reason RS has it "chattering". It seems RS noticed the pot(or the electronics design?) was not accurate/sensitive enough to bring the steering back to dead center. So they used a cheap trick and made it "chatter" back and forth so it goes straight. Did you ever notice while driving the car that it is also "chattering" at the same time? The frequency of the wheels chattering left and right is fast enough to make the car appear to be going straight. It does work for these tiny cars but the chattering noise is annoying. I guess that is something they thought was worth sacrificing.

Do you get what I am trying to explain?

[cyborgzero]

Originally posted by Whatup1049
Cyborg I think I have figured out why it doesn't recenter anymore and the reason RS has it "chattering". It seems RS noticed the pot(or the electronics design?) was not accurate/sensitive enough to bring the steering back to dead center. So they used a cheap trick and made it "chatter" back and forth so it goes straight. Did you ever notice while driving the car that it is also "chattering" at the same time? The frequency of the wheels chattering left and right is fast enough to make the car appear to be going straight. It does work for these tiny cars but the chattering noise is annoying. I guess that is something they thought was worth sacrificing.

Do you get what I am trying to explain?

ABSOLUTELY, and it is a VERY cheap trick at that! That makes PERFECT SENSE!!

Wow, okay, i have some new theories to test now. Great job!

I will try to get back to you all about the controller modding to get a dead spot in the centering.. I got mixed up with 2 cars being modded at the same time, and now I have to put the steering all back to stock since my notes dissapeared and start over... I think my dogs were messing with the notes, they get mad when I work alot, and just take random papers off my floor.. I don't leave my ZZs on the floor either because they think they are dog toys LOL...

Rob

And another thing that chattering is probably limiting the top speed aswell!

[cyborgzero]

Originally posted by Whatup1049
And another thing that chattering is probably limiting the top speed aswell!

OH YEAH it will, it might also cause the "dead car" situation too, due to constantly moving the steering motor.

[clxfiles]

Hey Cyborgzero, do you have any pics or diagrams of this mod? My reading comprehension isn't all that great when it comes to techo stuff like this. Pictures usually speaks volumes.

I don't have all the testing equipment you mention so I'm wondering, is all you're doing changing the bias resistors under the pcb board to matching, higher quality ones than what comes stock? Or is that pot you mention in the beginning stay on and let you adjust either side? If that's the case, how the heck do you get it all to fit??? What size resistors did you use on the three of your cars?

Thanks for all your efforts in these cars. I've read hundreds of threads since starting last month and you have given so much information to so many people it's amazing. Keep up the great work cuz you really make the these cars a LOT better for us.

So far it's all theory If I get some time maybe I'll try the resistor mod on the Tx and take some pics .

[Bri]

So what's the final word on this? Should we do the mod or is there a better solution for fixing the steering problem? If we do the mod, is there a fix for the problem with the lack of centering and with the sensitivity of the controller that results?

-Bri