Metal-gear micro servos for Summit -- SOLUTION FOUND
 

The transmission shift servo on my Summit crapped-out last night -- just locked up tight as a drum and then stripped itself out so I can hear the motor whizzing away constantly, trying to turn gears that no longer have teeth on them.

I'd like to replace them with metal-gear servos, but I can't find metal-gear micro servos that have the standard Futaba 25-spline hubs that the stock servos use. I've looked at Hitec, Futaba, and Savox. Am I missing something? What are other people using? I'd really prefer to replace the stock micro servos with metal-gear servos that have the Futaba 25-spline hubs, because that way I can keep the stock servo-savers for the diff-lock servos.

Alternately, if anyone knows of adaptors that fit onto micro-size servo hubs and adapt them to the Futaba 25-spline size, that would work fine too.

Help?

Re: Metal-gear micro servos for Summit?
 

Nevermind, I think I found a good solution. I'll know in a few days when it arrives.

Re: Metal-gear micro servos for Summit?
 

Please let me know how it goes. I've been having the same problem as yours, except 6 times in the last 4 months and it's always the on for shifting the transmission, the other two have been problem free. I've looked some but hadn't been able to find a better replacement.

Re: Metal-gear micro servos for Summit?
 

Same here.
I have killed 2 trans shift servos now. I want to replace them with better ones, but I can not find any that fit and work with the stock servo horns.
Also I need them to still be water proof.

Re: Metal-gear micro servos for Summit?
 

Finding one that's already waterproof is the dealbreaker. Fortunately it's not hard to waterproof a servo.

1) Open the back end and paint the circuit board with clear nail polish (or colored nail polish, if the color helps you notice spots you missed);
2) Open the front end and make sure the gears are thoroughly greased;
3) Some people fill the middle area, where the motor and potentiometer are, with grease as well, but thus far I've skipped that step and I've had no problems. Unless you're running in saltwater (pro tip: NEVER DO THIS WITH ANY RC EVER), a drop of water in the middle section of the servo should make no difference;
4) If the servo isn't gasketed, use a toothpick to apply a bead of Loctite around the edges of the servo case before reassembling; the Loctite will form a thin seal to help keep water out.

Hopefully the servo I ordered will arrive early next week. I'll post which one I got if it fits and if the direction of rotation is correct. I'm not trying to keep it a huge secret, I just don't want to waste people's time until I know for sure it works. I've seen too much idle speculation around the internet about which servos will fit, and I don't want to add to the morass.

Re: Metal-gear micro servos for Summit?
 

The Turnigy BMS-211DMH (rebranded Blue Bird digital coreless servo) does not fit. The hub is the right size and the right spline-count, and the width is and thickness are right, but the mounting depth on the servo is too deep. Strike one; on to the next possibility.

Re: Metal-gear micro servos for Summit?
 

Another problem with the BMS-211DMH is that it's coreless and digital, so it runs at full power constantly to maintain its position, since coreless servo motors have minimal resistance to rebound force from servo-savers, and there's no way to adjust the EPAs on the micro servos using the stock Summit radio. An analog servo with an iron-core armature may in fact turn out to be the best bet, and if so this will be the first time I've ever said "this servo is too fancy for this application."

Someone I'm corresponding with on another forum says the second servo I'm going to try does fit; I'll confirm when mine arrives.

Re: Metal-gear micro servos for Summit?
 

Keep us updated man!
I just replaced my shift servo again! Gears stripped in it again.

And yes I have the end points set correctly. And the shift shaft moves free. This time a small Stick got in there and jammed the servo up. Just bad luck I guess.

Re: Metal-gear micro servos for Summit?
 

My servos finally arrived. I'm swapping back and forth between the analog and digital servos to get an impression of which ones I want to use. The digital servos are definitely noisier at first, but they do settle down after a few seconds -- having an iron-core motor does seem to help with holding their position, as I originally predicted. The digital servos also move into position faster and stay in position when I torque the hub using a hex driver. However -- and this is the $80 question -- I'm not sure those attributes actually matter for this application.

For now I'm using the analog servos. I didn't really have any complaints about the performance of the stock servos, only about their durability. The new servos are definitely better-built, though I find myself wondering if I should buy a complete replacement set (instead of a single spare) just to be on the safe side, since Blue Bird isn't exactly a huge brand-name.

Anyway, here's a picture of the servos installed, with 6" extenders on all the wires:

http://i.imgur.com/eGzTNvm.jpg

The analog servos I decided to use are the Blue Bird BMS-373MG. The digital servos that I decided to send back -- but they do fit, if you really want digital servos for such a simple job -- are the Blue Bird BMS-375DMG.

Re: Metal-gear micro servos for Summit?
 

Just came across this thread so I thought I would chime in.

The shifting servo on my Summit finally let go and I had a TGY2-212DMH in my box. It's the same dimensions as the 211 but faster with less torque. I use these for steering on 1/12th and F1 pan cars. Anyway, since I had it I decided to put it in. It's been in there over a year now and still working. I can't remember having any depth issues when I mounted it though. I can take some pics later this week when I get home.



Sean 8)

Re: Metal-gear micro servos for Summit?
 

Hmm. It never occurred to me to use a micro servo on a race car to save weight.

Re: Metal-gear micro servos for Summit?
 

Only for 1/12th and F1. Here's a little video I made to show just how fast the 212 is.

https://youtu.be/MiCv9tUceYs

I'm going to try the 211 in my Summit as soon as I get one.



Sean 8)

Re: Metal-gear micro servos for Summit?
 

Just keep in mind you don't need fast servos for shifting and diff-locking duties. Honestly the cheapest servo that fits and doesn't break is all you need, and since they will be straining against servo-savers constantly when they're in-operation, analog servos actually work better because they don't strain with their full strength against the slightest resistance.

Re: Metal-gear micro servos for Summit?
 

Yeah I had the servo already and it was the only one that fit the Traxxas servo horn so I used it. I have a ton of other micro servos that fit but they all have the smaller output shaft. As you already know it's so hard to find a waterproof micro servo with a Futaba 25 spline output AND metal gears. :roll:

I have to admit I'm a bit of a servo junkie and every time I order from HobbyKing I always throw in a few cheap servos to test. Sometimes you find a real diamond in the rough. That's how I discovered the 212 for 1/12th pan cars.

Sofar this servo has lasted longer than the Traxxas 2065 that it replaced. I don't know about other Summit owners but my servo just stopped working. When I disassembled it the gears were fine so I suspect the motor or the driver failed from always straining against the servo-saver. The 211/212 has a coreless motor but it also has an aluminum body to dissipate the heat.

This would all go away if the radio had EPA for those shifting channels.



Sean 8)

Re: Metal-gear micro servos for Summit?
 

EPAs would be nice, but let's face it, Traxxas radios are all RTR-grade, even the 5-channel one that comes with the Summit.

Re: Metal-gear micro servos for Summit?
 

Wishful thinking. :lmao:



Sean 8)

Re: Metal-gear micro servos for Summit?
 

So it appears that the BMS-373MG has been discontinued by bluebird :( I can only find them on RcMart or Hobbyking from China.....

Re: Metal-gear micro servos for Summit?
 

Traxxas really ought to make a metal gear set for their micro servos.

Re: Metal-gear micro servos for Summit?
 

Like this one?

https://traxxas.com/products/parts/2065X

Re: Metal-gear micro servos for Summit?
 

Yes!!! Wow, have not seen that before even when searching, thanks! Now I need couple METAL replacement gearsets for the 2065 plastic gear servos I'm already running lol. "thumbsup"

Edit: found that too
https://traxxas.com/products/parts/2064X