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Tamiya mini cooper

Old 07-14-2015, 04:05 AM
  #24661  
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Originally Posted by Granpa

[...]

It's really in the DNA so this is why . . .

[...]
Oh god, please tell me you're not related?!
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Old 07-14-2015, 04:28 AM
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I find if subtrim is used to center steering, the more subtrim, the more imbalance the servo moves right vs left. Can be then cured by left/right EPA settings, but better if subtrim is close to zero (center).

Newer batteries = higher average discharge voltage = more speed
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Old 07-14-2015, 04:32 AM
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Originally Posted by rccartips
I find if subtrim is used to center steering, the more subtrim, the more imbalance the servo moves right vs left. Can be then cured by left/right EPA settings, but better if subtrim is close to zero (center).
It sounds like this is dependent on the type of radio. On my Spektrum the trim only moves the center position, leaving the full-lock positions the same. The subtrim moves everything the same amount.
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Old 07-14-2015, 05:13 AM
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Originally Posted by rccartips
I find if subtrim is used to center steering, the more subtrim, the more imbalance the servo moves right vs left. Can be then cured by left/right EPA settings, but better if subtrim is close to zero (center).
The way to avoid this is by setting the sub trim while everything else is zeroed. Setting sub trim after everything else is set will exaggerate the imbalance.
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Old 07-14-2015, 05:38 AM
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Originally Posted by sakadachi
Guys sorry for the confusion. I mixed up my SabreFD's servo setup with the M05.

Im looking at my chassis and now I know why everyone was confused. My bad my bad!!

Here's a picture of my Sabre next to my M05. For some reason my head thought the M05 also had the rectangular (perpendicular/parallel rod to servo) setup as my Sabre which triggered all the confusion and mess.

I take full responsibility for this one for sounding like an idiot.
Dude your not an idiot, your just a little too enthused and a little too into your own way of doing something. The reason for ignoring the servo, and stating that the rod needs to be 90 to the servo, is this exact reason. Offroad buggies, TC cars etc all use a single steering arm and need to be 90 to the horn, regardless of how the servo is mounted
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Old 07-14-2015, 06:22 AM
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Originally Posted by axle182
Dude your not an idiot, your just a little too enthused and a little too into your own way of doing something. The reason for ignoring the servo, and stating that the rod needs to be 90 to the servo, is this exact reason. Offroad buggies, TC cars etc all use a single steering arm and need to be 90 to the horn, regardless of how the servo is mounted
I totally understand this now. I had it in my head and once I looked at it on the table I saw it in 1 second. My car turns WAY better now.....because it's set up right. Really good group of guys in here.
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Old 07-14-2015, 06:29 AM
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Originally Posted by M05 newbie
I totally understand this now. I had it in my head and once I looked at it on the table I saw it in 1 second. My car turns WAY better now.....because it's set up right. Really good group of guys in here.
That made me happy. Im glad the explanation helped
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Old 07-14-2015, 09:24 AM
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Originally Posted by rccartips
I find if subtrim is used to center steering, the more subtrim, the more imbalance the servo moves right vs left. Can be then cured by left/right EPA settings, but better if subtrim is close to zero (center).

Newer batteries = higher average discharge voltage = more speed
Doc, how ya' been????? Glad to see you're still around. I've been fighting the cancer bug for about a year so the cars have been on hold. Built a couple of neat motors before the B/L conversion. Too bad they'll never see a race.

My point exactly. It's always better to build a "square" car where everything is at "zero" than slopping it together and compensating with a bunch of radio adjustments. This "close enough" building attitude is something that bugs me. Sure I've found only 2 servo savers in don't know how many, that were dead nuts, but with a little messing with the insert of most could get them pretty close.

I'd heard that the C rating on the batteries wasn't a reliable figure. I don't know much about these batteries, but am inclined to agree with this assessment having gone through the battery wars of the NiCad and Nimh era.

Couldn't agree more with the new battery comment. Batteries that haven't gone through a bunch of charge/discharge cycles will out perform those that have. Some guys were charging at "insane" rates to improve battery performance. Does this actually work????? I probably will never do this cause a new set of glasses would help my lap times more.
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Old 07-14-2015, 09:46 AM
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Originally Posted by axle182
Dude your not an idiot, your just a little too enthused and a little too into your own way of doing something. The reason for ignoring the servo, and stating that the rod needs to be 90 to the servo, is this exact reason. Offroad buggies, TC cars etc all use a single steering arm and need to be 90 to the horn, regardless of how the servo is mounted
axle- Don't worry, I know what you are saying and agree about the rod and horn. The issue was that I've been working on my SabreFD Mini the last couple of weeks as you know, plus 3 new Mini-Zs I bought and been playing with, and my memory of my M05 got fuzzy. Of course the horn and rod needs to be in a 90 degree angle, but would've been easier to explain if I just posted a picture like monkeyracing and not by fuzzy incorrect memory that the M05 had parallel rod and servo like my Sabre.

First world problems..having too many toys to play with and not enough time. Next time I will verify the chassis we're talking about before posting any instructions.
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Old 07-14-2015, 11:03 AM
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Hey guys...what is everyone running for motors. I'm looking for more speed. What should I look out for when upgrading aswell. I was lookin at a 3250kv package from cheetah. Someone mentioned the speeds earlier in the forum but just curious about what would be the best bang for the buck and what u guys are running?
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Old 07-14-2015, 11:17 AM
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M05newbie - for me, just the silver cans right now in my m-chassis with healthy Lipo's.
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Old 07-14-2015, 11:18 AM
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While you guys are diddling with the steering servo arm angle, keep in mind that while you can set the arm to be geometrically perfect, the servo itself can have different travel to the left and right for equal pulse width change. The feedback mechanism inside the servo is a potentiometer (from the wonderful world of analog components) which is guaranteed to have at least some non-linearity.

I just ended up changing radios in my M05, and the new radio doesn't have EPA adjustments, so I changed the length of the pushrod to get equal left/right turn radii just as we have been discussing. It doesn't take much change in length to make a big difference in the left/right endpoints!
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Old 07-14-2015, 11:28 AM
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Originally Posted by howardcano
While you guys are diddling with the steering servo arm angle, keep in mind that while you can set the arm to be geometrically perfect, the servo itself can have different travel to the left and right for equal pulse width change. The feedback mechanism inside the servo is a potentiometer (from the wonderful world of analog components) which is guaranteed to have at least some non-linearity.

I just ended up changing radios in my M05, and the new radio doesn't have EPA adjustments, so I changed the length of the pushrod to get equal left/right turn radii just as we have been discussing. It doesn't take much change in length to make a big difference in the left/right endpoints!
I like howard. He thinks like me. I hope you don't take offense!
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Old 07-14-2015, 12:22 PM
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I know Iīm a bit late to join the party, but thank you very much for explaining the geometrical subleties of servo linkage arrangements.

After more than 20 years of rc, I finally learned that it isnīt the car constructors thaughtlessness when the carīs turning radius isnīt equal left and right, but mine.

I really should have paid more attention at school.....
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Old 07-14-2015, 12:34 PM
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Originally Posted by Drachenschorsch
I know Iīm a bit late to join the party, but thank you very much for explaining the geometrical subleties of servo linkage arrangements.

After more than 20 years of rc, I finally learned that it isnīt the car constructors thaughtlessness when the carīs turning radius isnīt equal left and right, but mine.

I really should have paid more attention at school.....
Hey there, Drachenschorsch! I figured this out by trial and error when I was maybe 8 or 9yrs old putting together my first RC truck. I was, and still is, very picky about these things how it must line up perfectly left and right each time.

Another reason why I hate dealing with cars with left/right weight imbalance. I hate seeing one side of the wheel arch have a slightly wider wheel gap vs the other side.
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