Options to replace Micro Servo's?

[MattySlimz1987]

The fullsize Savox waterproof ones, (I believe the 0231 "tall" version) would be a great option. But would you run it on 7.4v to get the 200oz. out of it? And are fitment issues going to arise without some hacking... Yes these are the same price as Traxxas' plastic gear, 6v max servos so its a no brainer..

I still like CODYBOY's application of the Hitec 5065's.. 3 pole, top ball bearing and quick as lightning. I'm also betting Hitec is being slightly conservative on their 30oz. torque rating on this little thing too. Hope to hear back on the results of it..

[CoolRunning]

Great idea!

I'll use that for the front locker and buy a good Savox for steering as my stocker absolutely struggles cruising around creek beds and over rocks... it just cannot turn the wheels under load.

Until a locker is produced i'll use a zip tie for the rear; I might even pull the rear locker servo this week so I have a spare servo for backup.

I think I could use an SCX10 servo mount and screw it to a plate of aluminium and through the slider area sort of like stock... should be lots of room anyway.

Originally Posted by clm

You could always rehome the original steering servo to the diff lock duty when you put a good steering one in? It should have plenty of torque now that it's only trying to lock the diffs and not steer... and it is waterproof... and it came free with the truck

[clm]

Originally Posted by CoolRunning

Great idea!

I'll use that for the front locker and buy a good Savox for steering as my stocker absolutely struggles cruising around creek beds and over rocks... it just cannot turn the wheels under load.

Until a locker is produced i'll use a zip tie for the rear; I might even pull the rear locker servo this week so I have a spare servo for backup.

I think I could use an SCX10 servo mount and screw it to a plate of aluminium and through the slider area sort of like stock... should be lots of room anyway.

Hmm, if you moved the receiver you could probably put in a stand up servo mount right next to the stock locker servo mount and continue to use the stock mounting spot for the cables with a full size servo?

[CoolRunning]

I was thinking that I might be able to mount a full sized one lying down on the slider/side cover but in the same horn location as the micro shift servo with the end of the cable in the same spot but rotated 90 degrees. I'd move the RX box further rearward and do something similar with the shift servo.

[HumboldtEF]

Well I figured out a way to shorten the linkage a bit. I had ordered a new front cable thinking it may be shorter but it was the same length, but it did come with a new end link which gave me an extra to play with.

I figured out I could cut off a bit of the end link to essentialy shorten up the cable/linkage. For me it was an 1/8", but its gonna be a different for everyone I imagine. I drilled out the hole the cable threads into with a 1/16" bit all the way into the ball cup to maximize the thread grab.

If your cable is too short you can un-thread the cable a bit





Now the linkage has a throw thats centered on the servo.

I've yet to reassemble things so I'll report back again.

[CODYBOY]

Originally Posted by HumboldtEF

Well I figured out a way to shorten the linkage a bit. I had ordered a new front cable thinking it may be shorter but it was the same length, but it did come with a new end link which gave me an extra to play with.

I figured out I could cut off a bit of the end link to essentialy shorten up the cable/linkage. For me it was an 1/8", but its gonna be a different for everyone I imagine. I drilled out the hole the cable threads into with a 1/16" bit all the way into the ball cup to maximize the thread grab.

If your cable is too short you can un-thread the cable a bit





Now the linkage has a throw thats centered on the servo.

I've yet to reassemble things so I'll report back again.

Good job, and thanks for shareing!
Ernie

[El Matador]

Just thinking. If the servo is chattering like you say. I would inspect the wiring carefully. You might be getting a small short. I had a pin on the connector make a loose connection and man did that thing twitch.

[HumboldtEF]

So I have reassembled everything and its all working properly, I put a video together and combined it with the first one, skip to 3:17 if you've seen the first

https://youtu.be/RX46sRzpXwo





Keep in mind my front cable was long but maybe yours isn't so take a look and assess the length for your own rig. The threaded end on the cable is pretty long so if you cut too much and have to back it off a ways you still have a lot of grab.

Now this is the ideal throw and adjustment but maybe it still needs metal gears in the end, time will tell.

[Mudflap84]

You're the man! Great add on the video . I hope that bluebird shows up today


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[Terra Rover]

Here is a thought that I had. Use 1 servo to control both the front and the rear lockers. This servo set up would allow you to either lock or open both different at the same time. Us one of those dual arm servo arms and attach the cables to that.
For me, I feel that this would be all I would need. I don't think that I need to have one diff locked while the other is open. Just both locked or bothe open.
With this set up, you could open up to a variety of stronger, slightly larger servos. Plus there is less chance of something going wrong when you limit the electronics.
Just a though.

[awilson79]

Anyone tried the bluebird? I got the savox 0257mg with an xtm3860 servo saver. I was able to mount it in place of one of the diff lockers, but the size is off just enough that I wasn't able to connect it up to the cable. Going to play with it more and see if I can get it working. Also going to try it on the transmission. If someone confirms the bluebird works I may try that!!

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[CoolRunning]

Is that the 60oz Savox? The specs are great though I wasn't sure if it would fit.

I'm not sure I'd connect two diffs to a single double horn as any difference in the throw to get a diff locker engaged might cause issues. The servo is very weak too so it might struggle too boot. There unfortunately doesn't seem to be much wiggle room inside the truck either...I'm pondering if I can move the RX so I have more room atm to use big servos.

[awilson79]

It's around 30oz of torque. It fits fine. I had to take the top off and push it through from the bottom since the wire comes out the side instead of the bottom. Once I got it in, I put the top back on and it worked out fine. But the servo saver I tried is too stiff for the job. The stock servo savers have a ton of play and barely put any pressure on the wire at all even when they over-rotate the servo. To get the one I was trying to use to work, things would have to be done to a much better tolerance than what it is with the stock setup.

[capone93]

Originally Posted by svt923

I've heard of people using Bluebird BMS-373MG servos to replace the micro servos in the Summit. Metal gears, 25T spline, and supposedly mount right in place of the 2065 servos.

https://hobbyking.com/en_us/bms-373m...sec-11-4g.html

any feedback on these servos, would be great.

[HumboldtEF]

I just tried to rebuild one of the stock Traxxas micro servos simply as a test and I noticed that the sensor or switch in charge of stopping the servo internally is possibly another weak point. It will work in one direction but in the other direction the servo just keeps on trying to go. That's definitely gonna strip gears or burn it up. I put new gears in and while testing it ate the new set of gears (the same gear) because it wouldn't stop.

I noticed the new servo I put in just did something similar, I think this is likely the source of the buzzing, the servo has crummy internal end points. Short video to come later.

[Mudflap84]

Originally Posted by HumboldtEF

I just tried to rebuild one of the stock Traxxas micro servos simply as a test and I noticed that the sensor or switch in charge of stopping the servo internally is possibly another weak point. It will work in one direction but in the other direction the servo just keeps on trying to go. That's definitely gonna strip gears or burn it up. I put new gears in and while testing it ate the new set of gears (the same gear) because it wouldn't stop.

I noticed the new servo I put in just did something similar, I think this is likely the source of the buzzing, the servo has crummy internal end points. Short video to come later.

HumboldtEF I installed the Bluebird 373 mg front and rear with the servo savers and rear has already died. I dont think a sub micro is ever going to handle the job with any reliabity. I have decided to leave the rear locked for good. If/when the front servo fails,I will replace it with a full size unit. On a positive note, your mod on the front cable has it operating perfectly

[Frank211]

Originally Posted by Cletus Brown

My front servo failed and Traxxas is said they're sending me a new gear set.


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Just a set of gears.
WOW that seems mighty cheap of them. You'd figure a whole new servo

[HumboldtEF]

Here's a quick video in how the sensor inside works or rather doesn't work.

EDIT As CLM has pointed out below the pot has a home not end points. thanks to the advice I attempted a rebuild again and centered the servo first by plugging it into the steering channel. I haven't stripped the gears yet testing it, but I've yet to install it.
I believe I had the pot offset to one side (when I did the first rebuild) which likely made the servo wind itself into the stop making it strip the new gears immediately.


https://youtu.be/04lZ5OP_ksI



Another thought popped into my head, I though I had read in a post that the stock ESC used a 1A BEC, maybe its low for the sake of these wimpy servos and regular ESC's might overload them? just a thought.
I did this test using the stock ESC.

Originally Posted by Mudflap84

HumboldtEF I installed the Bluebird 373 mg front and rear with the servo savers and rear has already died. I dont think a sub micro is ever going to handle the job with any reliabity. I have decided to leave the rear locked for good. If/when the front servo fails,I will replace it with a full size unit. On a positive note, your mod on the front cable has it operating perfectly

Well that's unfortunate, but good to know I guess. I wonder if the transmitter/receiver are partly at fault here too, seems like there's a lot of factors working against it.

[Mudflap84]

Originally Posted by HumboldtEF

Here's a quick video in how the sensor inside works or rather doesn't work.

https://youtu.be/04lZ5OP_ksI



Another thought popped into my head, I though I had read in a post that the stock ESC used a 1A BEC, maybe its low for the sake of these wimpy servos and regular ESC's might overload them? just a thought.
I did this test using the stock ESC.



Well that's unfortunate, but good to know I guess. I wonder if the transmitter/receiver are partly at fault here too, seems like there's a lot of factors working against it.

Need to be able to set endpoints for sure-I have too many irons in the fire to buy a decent Tx/Rx right now

[clm]

As I posted on youtube, that servo position pot is working as it's supposed to. the channel it is on currently has the orientation off to one side so off to one side is where the off point of the potentiometer is as centered, as you twist it either direction from that point the motor will spin and attempt to, through the servo gearing, reposition the servo output back to the off point on the potentiometer. This is why the servo motor spins quickly in one direction when you twist it one way and then quickly in the other direction when you twist it that way.

Easy way to see this is to plug that servo into the steering channel. power up the radio and then center the potentiometer so the motor stops, then on the radio turn the wheel back and forth, you will see the motor spin one way then the other in accordance with how you turn the wheel.