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  1. #1
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    Servo questions on flm emaxx

    Ok I got a couple questions regarding the 2 servos I just got for my eMaxx and other truck. (hitec 7954 and Savox 1256). I hooked the hitec up to my flm eMaxx seems to be working ok. I have the Voltage set at 6volts thru the traxxas link (will bump to 7.4 when my new Rx comes in. On carpet The hitec steers left pretty good but it seems like it has trouble steering right from a stand still. I had that problem with the stock dual traxxas servos. Why am I having that problem? It is also kinda noisy. It whines like an almost constant electrical high pitch noise. It's also not getting quite as much motion to the right when driving. but I think it cause the linkage is hitting the servo saver so it is stopping it a little short. But that is fixable.
    My next question is about the Savox 1256. I plugged that in and when I turn right it glitches/twitches. The guy gave me a couple glitch busters and it does stop when I plug that in but why does it glitch like that? Can I stop that from happening without the glitch buster? Or is there something wrong with the servo?

  2. #2
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    I believe the issue with the Savox is they draw more power than the BEC on the ESC can provide. Get a stand alone BEC and they should work fine.

  3. #3
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    Someone answered this for me before but I can't recall where it was. But when I use a castle BEC I can hook that up to the castle link and change the voltage right? And when I use the Castle BEC do I need to do anything with the internal BEC or will the external BEC automatically make the internal stop sending the voltage out?

    And why isn't the servo turning left properly? Using the Hitec it is 333oz at 6V and 402 at 7.4. I have it set at 6. I would think that standing still it would be able to make full turns. I can turn right without a problem but from full right I can't turn full left. It goes to about center then stops. Even if I try turning left from center it doesn't go full turn.

    I also want to use an alum servo arm. It is a hitec 7954 but what size do I get? 23T, 24T, 25T?
    Last edited by Slapjack; 03-03-2015 at 09:30 AM.

  4. #4
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    Savox servos are glitchy by nature, most of them require either a glitch buster or an external BEC. I have no complains with either Hitec or savox but in my experience hitec runs quiet and smoother. My guess is you might have a binding somewhere on the steering, also make sure the servo is centered before installing the servo horn so you have equal travel.

    You got a hitec servo horn right? stock won't work with hitec servos only with savox. If not wrong hitec is 24t, stock is 25t, also savox and futaba.

    Check for binding first, center the servo, bump the voltage to 6.5v. I never had any issues runnig 7955, 7954, and savox 2270 on 6.5v neither needed a BEC or glitch buster with those.

    If you are going to install an external BEC you need to unplug the positive wire coming from the esc, if not you will fry everything. And yes you can adjust the voltage on the bec trough castle app.

    Last edited by NFS; 03-03-2015 at 09:43 AM.

  5. #5
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    Quote Originally Posted by Slapjack View Post
    Someone answered this for me before but I can't recall where it was. But when I use a castle BEC I can hook that up to the castle link and change the voltage right? And when I use the Castle BEC do I need to do anything with the internal BEC or will the external BEC automatically make the internal stop sending the voltage out?

    And why isn't the servo turning left properly? Using the Hitec it is 333oz at 6V and 402 at 7.4. I have it set at 6. I would think that standing still it would be able to make full turns. I can turn right without a problem but from full right I can't turn full left. It goes to about center then stops. Even if I try turning left from center it doesn't go full turn.

    I also want to use an alum servo arm. It is a hitec 7954 but what size do I get? 23T, 24T, 25T?
    To run the external bec, you will have to pull the red wire out of the ESC plug to disable the internal bec. It is also programmable via castle link just like the esc. As far as the turning, if take the horn back off, make sure its centered and trims are set then put your horn back on. Some tx have dual rate steering trim and then a regular steering trim setting, id make sure those are set aswell. I can't recall what hi tec spline count is but I'm sure a simple Google search should yield an answer.

  6. #6
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    Thanks guys, I appreciate the help. Just to make sure I got this down though..... let me know if this is correct. I like to write it out so I totally understand what I am doing.

    Ok, so I solder the CC EBEC + to the + battery connector terminal and the - to the - battery terminal. Then remove the red wire from the esc throttle plug going into the Rx (what do I do with it? just zip tie it to the other wires and leave it disconnected from everything?) .Then plug the other end of CC EBEC (standard wire connector) to the extra Rx channel? Can I use the Y harness here since I currently have the ESC fan plugged into that channel?

    So after doing this is the CC BEC powering the servo and the rx? So then I just plug the end that goes to the RX into the castle link and program it? I would use either r6V for the savox or 7.4 for the hitec (which is the ratings)? and then Im set.

    How do I center the servo? Is that little notch the center? I should have that pointing forward in the center? Then I can place the horn wherever I want right, because it will still move 60 deg from wherever I start the arm (as long as it is centered)? Servo was pretty noisy as well. Does that matter?
    Last edited by Slapjack; 03-03-2015 at 10:30 AM.

  7. #7
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    Ya I just zip tied or shrink wrapped the wire to the the others. Plug the cc bec into an extra channel. The voltage will depend on what the Rx and servo can handle. Once this is done the bec will power the Rx and servos only, so when you plug your batteries in, they will instantly power on but the ESC will not till the switch is turned on, keep that in mind. If the servo is buzzing and seems loud I would say its binding up somewhere. At a stand still it shouldn't be making a lot of noise. You shouldn't place the horn on the servo then turn it were you want it.....that's incorrect, center the servo then you use your trim settings to place the horn where needed.

  8. #8
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    Ok so center the servo with the notch in the shaft then put the horn as close to where I need it and if the linkage doesn't line up perfect use the the trim to move it slightly? Gotcha. Now the issue I have is that where te servo is mounted the little linkage arm has to angle up very slightly to reach the arm. I think that is why it's binding when I turn left. I've tried mounting the linkage to the top of the arm and bottom. Andnit has to be angled both ways. This is with the servo being mounted from under the chasis. If I mount it on top of te chasis it's makes the angle even worse just in the opposite direction. I'll try some shims maybe that will work.

  9. #9
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    Ya with the binding that's odd. I thinkits a hit or miss with the flm chassis on mounting servos under or on top of the chassis. I have seen both. I mount mine on top and don't have binding issues. By mounting on top they fit flush. I do have some tight clearance between the drag link and dog bone then the bellcrank and bulks but nothing binds fortunately. I imagine finding some shims would do the trick. A while back I suggested the servos I'm using, I see you decided on something else bud. Either way its odd that its angled like such.

  10. #10
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    Ya I'll give the shims a shot after work. Ya I bought these servos based on price. I got a real good deal on them both. No I gota mess with this radio that just got delivered at my work. I got the 4pls futaba but I just pulled it out of the box and as soon as I grabbed it I could hear some rattling. There is something inside rattling around. I don't like that. Debating whether to try it and see if it works or if I should just send it back

  11. #11
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    My question is have you actually ran this truck yet since you built it? I've tried to help you along the way and I'm curious if you have actually gotten the chance to drive this thing like it should? I know you have had some issues and bad weather but man, free some time up and let's see a video lol!

  12. #12
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    Lol, I drove it at the college down the street a few times but something would go wrong every time. I finally had it all wrapped up and good to go (I drove it last weekend in a parking lot and nothing went wrong finally). And now Im tearing back into it to replace the servo and Rx and a whole new set of issues arises.... but it sucked at the parking lot because all I could is donuts. I gopro'd it but its really boring to watch, I couldn't get any traction and just kept spinning out. it is getting very close though for a little better weather. The other thing that stinks is you can't drive this truck in anything over an inch of snow or it just buries itself. I gota get another Summit for Winter Fun. I can't wait to really drive this thing though.

  13. #13
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    Ya I took mine in the creek a few times and the sand is like quick sand, so it would just bury itself sometimes. I'm on sc and we didn't really get any snow.....I freakin wish it would tho I have been wanting to take it out in it. But anyways, I hope you get it soon man, this truck is a blast to drive. I'm getting another set of lipos soon so I can play just a bit more longer lol. I've got all the bugs worked out on mine and so far its been ran pack after pack so I'm happy

  14. #14
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    Ok I got the centering thing and adjusted it with the steering trim to line it up with the linkage arm. I got the aluminum arm to fit finally but the holes in the arm are small and I can't fit the regular 3mm screw thru it. Why would they make them so small? And how am I going to attach to it?
    Nevermind I guess I'm just gna buy a new arm with threaded holes for 3mm hardware. Not sure why they would include an arm with tiny holes like that. Even all the plastic ones are like that I had to drill them out. Oh we'll new arms are cheap enough


    Edited for language abuse.
    Last edited by cooleocool; Yesterday at 08:58 AM.

  15. #15
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    Are you referring to the aluminum arm? Aftermarket? I've had good luck with the stock ones.

  16. #16
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    This is the best servo horn you can have.

    http://www.amazon.com/Racers-Edge-Al.../dp/B003T6TU7G

  17. #17
    RC Turnbuckle Jr. Wildman4910's Avatar
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    I prefer the Ofna servo arms, either the Racers edge or Ofna is a great choice.
    http://www.amain.com/ofna-cnc-machin...-hitec/p197370
    http://www.amain.com/ofna-cnc-machin...ox-ace/p197372
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  18. #18
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    I like that ofna it seems to be a lower profile, might give it a try.

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