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Old 10-08-2007, 07:14 PM   #1
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Default weird steering issue...

I just got an Airtronics M3 radio for my B4, and I can't get the car to run straight. When I turn right and let the wheel go back to center, it veers to the left. When I turn left, it veers to the right, which seems opposite of what it should do if there was play in the linkages or something. I tried the steering trim, sub trim, checked the toe in/out, and I centered the servo horn on the servo. The servo saver is on the loose side, but I doubt that that's the problem. What's the difference between steering trim and sub-trim? I centered the steering trim and am using the sub-trim to "center" the servo. Is this right?
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Old 10-08-2007, 07:28 PM   #2
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Did you try the "servo reversing" on the radio. Skim through the manual on how to do this. Sounds like it is just backwards is all.
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Old 10-08-2007, 07:34 PM   #3
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It turns the right direction, but after it turns and it goes back to "straight" it veers in the opposite direction that it was turning in. Does that make sense? If I turn right, the car goes right, but when I let go of the wheel to go straight, it veers to the left. It does the opposite if I turn left. It's kind of hard to explain, I guess.
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Old 10-08-2007, 07:42 PM   #4
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Make sure that servo saver is tight! Use the heavy duty spring in the servo saver too! If that doesn't fix it, it could be a radio or servo issue.
We'll be at DH on the 20th, I could take a look at it if you want.

P.S. Sub-trim gives you finer adjustments than steering trim.

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Old 10-08-2007, 07:51 PM   #5
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I'll crank the servo saver down and see if that fixes it. I don't think it's the servo, because it worked fine until I put it in the B4 with the new radio... I don't think I'll be able to make it to DH that weekend, but thanks for the help
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Old 10-08-2007, 08:22 PM   #6
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That sounds like a servo centering issue. Something is not letting the servo center properly. And like above, it could be too loose of a servo saver, gear teeth in the servo stripped, or some type of binding in the linkages.

Take the servo horn off and move the wheels right to left and try to find binding/drag somewhere. On my T4 I run the servo saver pretty much locked down. The servo I have is stronger than the truck anyway. LOL. Kidding. My issue was I couldn't get full steering travel to the right and left. I shoe goo'd the thing together and problem went away.
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Old 10-08-2007, 08:48 PM   #7
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Can you be very specific about all of the electronics you are running? I have had some weirdness in the past and the source was odd.
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Old 10-09-2007, 07:41 AM   #8
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Thanks for the help, guys. I'm running an Airtronics MX3 radio w/ Hitec receiver and JR 590 servo. I have been running the servo with an Airtronics AM radio in my SBV2 buggy and T4 without a problem. Actually, it never really centered completely, but instead of overcentering, it didn't quite make it back to center. I'm pretty sure that was from steering slop, and it wasn't as dramatic as what it's doing now..
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Old 10-09-2007, 02:15 PM   #9
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Take the front half of the servo cover off exposing the gears. Pull off the final gear (the one that exits the case) and flip it over. There is usually an insert in it that wears out and won't make tight contact with the pot shaft in the servo and this can cause your issue. Replacements are as close as your local hobby shop.

The other possibility while you have it apart is the nut (assuming your servo uses one) that holds the pot in place has come lose and is allowing the pot to walk a little when it rotates. If you see a recessed nut on the pot when you have the final gear off, make sure it's snug!

Either part only needs to allow a fraction of a millimeter play to yield great big results at the linkage. Good luck!

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Old 10-09-2007, 05:08 PM   #10
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Thanks for all the help! I'll probably spend Thursday trying this stuff and fixing my Academy buggy There's always something!
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Old 10-09-2007, 05:41 PM   #11
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Sounds to me like you got a bad 590. Theres a big suprise. They are not known for their durability.
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Old 10-15-2007, 02:56 PM   #12
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So there is a tiny amount of play in the servo somewhere. I'm pretty sure that this is the problem, but I can't figure out if the play is comming from the gears or somewhere more inside the servo. The gear mesh seems tight enough, so I don't know how to fix it. Maybe it's time for a new servo
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Old 10-17-2007, 09:31 AM   #13
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i'll get you one from cody's huge stack of rc stuff in his room he never uses. But yea maybe that wreck you had with the wheeler killed your servo? If the force can mingle four things on your car maybe it hurt the servo. Did you take it apart yet?
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Old 10-17-2007, 11:39 AM   #14
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Maybe you servo is missing a tooth on one of it's gears I've had this happen a few times take the servo out and turn it from one end to the other if theres a gear missing you will feel it.
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Old 10-17-2007, 05:58 PM   #15
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Huh... Yeah, I suppose that might have had something to do with it... I did take it apart and I didn't notice anything wrong with the gears, but I didn't check all the teeth, either. I just checked for backlash and I didn't notice any in the teeth. It almost seems like it's coming from further inside the servo. Hey Brad, if Cody does have something laying around, bring it with you if you can. It's hard trying to brake when your car doesn't go straight Once again, thanks for all of your help, guys!
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