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  1. #1
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    single servo conversion pros & con & what's a good servo for lipos

    Just like the heading says help guys....

  2. #2
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    The battery doesn't make a difference on the servo unless you are running it direct.

    There are really no cons to single servo, the pros are that there will be no fighting between the two to align from lock to lock. That increases life. Less weight, but in a revo that's not a big concern for most people.

    I like the Radiopost Torque model servo I bought, it does 330Oz*In @ 6.0V. fast too.

  3. #3
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    Single servo: one servo to tune, no contradicting each other and less weight and wires. More power, better looks, just better overall.

    I'm not sure what you mean by "good for lipo" it all goes through a bec before it hits the servo. With a heavy power drawing servo I would recommend the castle 10amp bec.
    I reject your reality and substitute my own!

  4. #4
    RC Turnbuckle Jr. MITCH316's Avatar
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    Here are 3 of my single servo mods

    http://traxxas.com/forums/showthread...=1#post5284328

    http://traxxas.com/forums/showthread...=1#post5300665

    http://traxxas.com/forums/showthread...=1#post5342651

    Since I have done the single servo mod I'll never go back to dual. They are all working well and are very responsive.
    Rock n Rolla !

  5. #5
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    Quote Originally Posted by Money pit View Post
    Single servo: one servo to tune, no contradicting each other and less weight and wires. More power, better looks, just better overall.

    I'm not sure what you mean by "good for lipo" it all goes through a bec before it hits the servo. With a heavy power drawing servo I would recommend the castle 10amp bec.
    Not all run their servos powered by the onboard BEC. I have HV servos made to run directly off 2s. The battery really doesnt matter anyhow, just has to be 2s if you go the HV route.

    Im running JR Z9100HVTs in both of my ERBEs, 480oz of torque at 7.4V in a single servo set up. Less weight, less linkage to bind, less slop, easier set up and tweaking.

    You only need the castle 10amp BEC if you are running a Castle ESC. Tekin handles high torque servos with no problems. The brand I recommend is anything but a Savox.

  6. #6
    RC Turnbuckle Jr.
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    Running my hitec 7950th through a bec at 7.4 v so I get 486oz at. 13 sec. Nice and powerful and quick with titanium gears!
    And I now have two spares for my e maxx!
    Last edited by 50togo; 01-07-2013 at 10:26 PM.

  7. #7
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    what does a bec do.... I run 6s

  8. #8
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    In the case of castles bec it gives you 10amps and up to 7.4 volts for your servo. Lightens the load on the esc and If your servo can handle 7.4 will give you more torque and speed
    Some servos like savox are power hungry and a never is a must. I used one to increase torque from 403 to 486ozs

  9. #9
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    so what your saying is that i can use any servo but the bec just makes the less power hungry, are there any servos out there that use less power...? i don't think I'm getting it...
    Last edited by Revoiest; 01-08-2013 at 12:27 AM.

  10. #10
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    If you are running the stock mamba esc it has a weak internal bec. With a power hungry savox servo you would need a castle bec or if you have a high voltage servo that can run 7.4v you will get more torque and speed.
    A hitec servo running 6 volts wont need a bec

  11. #11
    RC Turnbuckle Jr. 87 GN's Avatar
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    & post #51 how to wire it up......
    http://traxxas.com/forums/showthread...=1#post4915749
    Would you go flip my truck back over??

  12. #12
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    so my new qustion is how are the 2 stock revo servo not burning up, they dont run a BEC....

  13. #13
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    They aren't that powerful and don't draw much

  14. #14
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    are there any upgraded servo (1) out there that dont need bec

  15. #15
    RC Turnbuckle Jr.
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    Buy a hitec!
    My servo didn't need an external bec I just wanted 7.4 volts!
    Last edited by 50togo; 01-10-2013 at 11:31 PM.

  16. #16
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    which did you get...? is it just plug & play...?

  17. #17
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    Having done the same as craig.mitch316, I just installed the Savox 1230sg and am very happy with its performance. ($66 on eBay)

    Steering is vastly improved. Also got my HPP hubs today and that helps a heap too.

    I'm just running it off the EVX-2 2.5A BEC ATM but have a Hobbywing WP-SC8 120A on its way and it has a 3A BEC.

    I mounted it using two of the original flat head screws and two bolts with washers and nylocs. I popped the servo gear case and put some silicon grease on the output shaft. It had an o-ring on the inside. I siliconed around the base and the servo case screws also had little rubber washers like the 2075 servo. I put a small o-ring between servo horn and case on the spindle shaft to help with water resistance.

    This servo did hum a little initially but seems much quieter after a days running.

    I've got the aluminium single servo arm coming and can see I might also stiffen up the spring in the servo saver. 500oz/in is much better than 250oz/in twin servos.
    Summit 11/68T 4S 2000kV
    E-Revo 14/56T 6S 2200kV

  18. #18
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    Quote Originally Posted by 50togo View Post
    Running my hitec 7950th
    I used a Radiopost Torque (RED) servo both standard off the receiver at 6.0V and then upgraded it to a CC BEC at 7.4V and left the receiver at 6.0V from the MM ESC.

  19. #19
    RC Turnbuckle Jr. 87 GN's Avatar
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    This servo did hum a little initially but seems much quieter after a days running.

    Crazy buying a new single servo, & it sits there & humms. My Hitec did that & so does the Savox, few runs,
    then they kind of get broke in....
    Would you go flip my truck back over??

  20. #20
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    Quote Originally Posted by 65535 View Post
    I used a Radiopost Torque (RED) servo both standard off the receiver at 6.0V and then upgraded it to a CC BEC at 7.4V and left the receiver at 6.0V from the MM ESC.
    I wired mine the same. I wanted 6v to the esc and 7.4 to the servo. Don't cut any wires either just used a few extensios

    Mine did some humming too when new

  21. #21
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    My radiopost doesn't hum, and when off there is little resistance or noise when moving the tires. I like it.

  22. #22
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    Im actually going to try something different for the servos I have. They are all HV servos meant to run directly off of 2s Lipo. Well instead of soldering into the battery lead Im using the balancing leads for power. A little customization on a balancing lead extension and all set. Im going to try running dual HV servos for giggles and see how it pans out. Seeing how I got a sweet deal on a pair of JR's Z9100HVT and Z9100HVS Im going to see how they react together. One of the draw backs to high torque is you lose speed, well what if a high speed is assisting the high torque? Ill soon find out!

  23. #23
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    Not well, the high torque servo will pull the high speed servo around, they'll constantly fight with every different input and likely drain more power and cause strain on the entire system.

    Also make sure if you decide to run your servos off your balance port on your packs that you keep the ground common. The ground is the negative terminal of the pack connected to the ESC. If you pull power from the wrong taps on the balancing connector or the wrong pack you'll short out the pack and likely fry your entire electrical system.

    It's a bad idea at best. You'll also want to keep a ground connected between the receiver and the servos regardless of the power supply so you can have a solidly grounded DC system on your truck. That will prevent glitching.

    If it was me, I would use the high torque servo running at 7.4V off a CC BEC and forget about the speed servo, use it in a 10th scale vehicle.

    I run a Radiopost Torque servo at 7.4V which is 419Oz*In torque and .09s/60deg transit time. I have a CC BEC wired in parallel to the MM ESC to a Y-cable to the Servo, removing the positive pin at the receiver. That prevents any voltage issues, or frying anything.

    If you want plug and play just set the ESC BEC to 6.0V and plug the servo into the ESC normally.

  24. #24
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    Sorry I don't want to hi hack this thread,but I need some help here also.I bought a used e revo,about a month ago for 100 buck and sold the evx 2 for 30. Now here is where I need help,one of the servos was bad.I had a couple of hitec HS-645MG servos in a box.I ordered a Hobbywing WP-SC8 120A esc,now my ? is ,should I get a bec?,if I want to use them both.

  25. #25
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    Normally not with hitec servos. It is 6v/3a you should be good
    Last edited by 50togo; 01-15-2013 at 12:32 AM.

  26. #26
    RC Turnbuckle Jr. rjm2519's Avatar
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    Just be careful with your gearing on that esc, it doesn't like to be pushed hard, don't ask me how I know. I ended up getting a 150 amp for my revo the 120 that replaced my original is still looking for a home. I use a savox off the ezrun esc without issues. Only 222 oz in of torque but has not issue getting truck turned where I want it to go.
    Donít handicap children by making life easy

  27. #27
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    so if I use them both it should be ok,only reason Im asking is because of rjm2519.I read his post where he,well fried the mess out of his.also I appreciate the help, Thanks
    Quote Originally Posted by 50togo View Post
    Normally not with hitec servos. It is 6v/3a you should be good

  28. #28
    RC Turnbuckle Jr. rjm2519's Avatar
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    That had nothing to do with the servo that was with the esc. If you see the 120 and 150 side by side you will seriously question the 120 amp rating. If I read the post right you should be good with the two hitec servos.
    Donít handicap children by making life easy

  29. #29
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    Quote Originally Posted by rjm2519 View Post
    That had nothing to do with the servo that was with the esc. If you see the 120 and 150 side by side you will seriously question the 120 amp rating. If I read the post right you should be good with the two hitec servos.
    just making sure,never can ask to many questions.also your esc,had a massive heart attack.

  30. #30
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    Quote Originally Posted by 65535 View Post
    Not well, the high torque servo will pull the high speed servo around, they'll constantly fight with every different input and likely drain more power and cause strain on the entire system.

    Also make sure if you decide to run your servos off your balance port on your packs that you keep the ground common. The ground is the negative terminal of the pack connected to the ESC. If you pull power from the wrong taps on the balancing connector or the wrong pack you'll short out the pack and likely fry your entire electrical system.

    It's a bad idea at best. You'll also want to keep a ground connected between the receiver and the servos regardless of the power supply so you can have a solidly grounded DC system on your truck. That will prevent glitching.

    If it was me, I would use the high torque servo running at 7.4V off a CC BEC and forget about the speed servo, use it in a 10th scale vehicle.

    I run a Radiopost Torque servo at 7.4V which is 419Oz*In torque and .09s/60deg transit time. I have a CC BEC wired in parallel to the MM ESC to a Y-cable to the Servo, removing the positive pin at the receiver. That prevents any voltage issues, or frying anything.

    If you want plug and play just set the ESC BEC to 6.0V and plug the servo into the ESC normally.
    Im not the average joe, Electronics Engineering is what I do for a living but thanks for clarification for anyone who reads this.

    Well so far so good. What I did for power was run the lead directly off the balancing port on a 2s lipo to the Rx (yes my Futaba R614ff is rated for it) so they both get the same power source and using a short servo lead attached to the ESC with the + removed on the lead instead of the ESC wire. As predicted they work well together and do not fight eachother in the least. I connected the high torque servo first and aligned the steering then connected the high speed and nulled it out which was quite a bit easier on a Futaba radio. High torque is on channel 1, High speed is on channel 3 with a mix program applied. After all the mechanical adjustements made a +1 offset to channel 3 and they run in perfect harmony and move those 40 series big joes like they were nothing and move them fast! I did remove one at a time to see the impact of single vs dual and high speed only vs high torque only to make sure it wasnt a waste of time. There is a marked difference between the different configurations. Both connected the steering moves lightning fast end to end, faster than with either single. High torque only moves faster than high speed only, due to the load of the big joes.

    Ill post back if I get an adverse effects over time as this is experimental.

  31. #31
    RC Turnbuckle Jr. rjm2519's Avatar
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    You could say that, more like heartburn!



    Comparing the 120 amp and 150 amp esc!

    Donít handicap children by making life easy

  32. #32
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    I don't see any difference between the two!

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