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Axial 1/18 Yeti (and Yeti Score)

Alright, got the new servo installed. Hitec HS-85MG, 49oz/in at 6v so almost double stock torque, the size specs are 29x13x30mm, it's a 23 spline output, and it was cheap. Picked it up at the LHS for $22. This servo fits like it was made for the Yeti JR., with just a tiny bit of room everywhere so there's no contact on the center shaft or anywhere else. If you're looking at replacement servos, stay as close as you can to these dimensions for a good fit. There's maybe another 2-3 millimeters on the back side before hitting the center shaft but there's only a millimeter or less of available width before needing to modify the chassis pan. The Hitec HS-5085MG is good for another 10oz/in of torque for a total of 60oz/in at 6v and is almost the exact same size but the LHS didn't have one. If this one fails, I'll move up to the 5085. Here it is all tucked in and ready to go. There was no way to fit the servo saver without cutting the side of the chassis off so I need to find a way to attach it to the steering rack now. I'll post up my solution as soon as I figure it out.
 

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Good to know about the Servo..
I just want one to Build a scale IFS chassis for a 1/10 rig without the wheels sticking out
past the body. ;)
 
Alright, got the new servo installed. Hitec HS-85MG, 49oz/in at 6v so almost double stock torque, the size specs are 29x13x30mm, it's a 23 spline output, and it was cheap. Picked it up at the LHS for $22. This servo fits like it was made for the Yeti JR., with just a tiny bit of room everywhere so there's no contact on the center shaft or anywhere else. If you're looking at replacement servos, stay as close as you can to these dimensions for a good fit. There's maybe another 2-3 millimeters on the back side before hitting the center shaft but there's only a millimeter or less of available width before needing to modify the chassis pan. The Hitec HS-5085MG is good for another 10oz/in of torque for a total of 60oz/in at 6v and is almost the exact same size but the LHS didn't have one. If this one fails, I'll move up to the 5085. Here it is all tucked in and ready to go. There was no way to fit the servo saver without cutting the side of the chassis off so I need to find a way to attach it to the steering rack now. I'll post up my solution as soon as I figure it out.

I probably should have picked the HS-85 I guess. Instead I have an HS-65
on the way cause it's size mirrors the stock servo size. I could always move it over to my Teton and reorder.
 
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Alright, got the new servo installed. Hitec HS-85MG, 49oz/in at 6v so almost double stock torque, the size specs are 29x13x30mm, it's a 23 spline output, and it was cheap. Picked it up at the LHS for $22. This servo fits like it was made for the Yeti JR., with just a tiny bit of room everywhere so there's no contact on the center shaft or anywhere else. If you're looking at replacement servos, stay as close as you can to these dimensions for a good fit. There's maybe another 2-3 millimeters on the back side before hitting the center shaft but there's only a millimeter or less of available width before needing to modify the chassis pan. The Hitec HS-5085MG is good for another 10oz/in of torque for a total of 60oz/in at 6v and is almost the exact same size but the LHS didn't have one. If this one fails, I'll move up to the 5085. Here it is all tucked in and ready to go. There was no way to fit the servo saver without cutting the side of the chassis off so I need to find a way to attach it to the steering rack now. I'll post up my solution as soon as I figure it out.

The ball stud on the bell crank is the same size as the losi micros and mini-t. You can use rod ends from those or the redcat sumo or associated rc18 series, with some 2-56 or 2mm threaded rod.

 
Alright, got the new servo installed. Hitec HS-85MG, 49oz/in at 6v so almost double stock torque, the size specs are 29x13x30mm, it's a 23 spline output, and it was cheap. Picked it up at the LHS for $22.

Thanks for the info on the servo, trying to source one now but not having as good of luck as you in terms of price. I'm also curious if anyone has tried to use rod ends like TownsendTDI mentioned for steering linkages. I noticed an exagerated toe in on my TT and think this solution could help at least provide adjustment to the link. Only thing I'm not sure about is if the ball studs are the same size for these links as well.
 
This servo fits like it was made for the Yeti JR.

Nice! I have one of those in my XRay M18 and a spare in my toolbox. "thumbsup"

There was no way to fit the servo saver without cutting the side of the chassis off

Oh, that seems too big then.

Gotta stick with my Spektrum. It's bigger than stock but the servo saver and steering link still fit and work with no mods other than a washer on the servo saver.

I've beat on mine pretty hard since the upgrades and it hasn't missed a beat. There's a little jump where my yard meets the street that I've hit dozens of times with it and I get the biggest kick out of it every time. It handles about half of my crawler track, mainly the slate and hill sections. Obviously, the bricks, boulders and the stump are a bit much for it. I've also got a small figure 8 I'm running around two trees so half my course involves trying to keep it on all 4 wheels at the highest speeds it can handle.

It flips so easily though. Even with expo to soften the center, a little too much speed in a turn and the front tire digs in and over it goes. I'm afraid going from 30wt to 10wt shock oil up front as suggested earlier will make it even easier to flip.

I want to try some 3S runs in the street if it ever gets above freezing outside. Winter isn't messing around this year.
 
I called and spoke to someone a few minutes ago regarding my lack of steering. They said they would drop a new servo in the mail tomorrow, however, after reading this thread I suspect I should just get a better one.

I'm new to this so if anyone wants to guide me in the right direction, I would appreciate it. until then, I'll use the search function and try to gather as much info as I can.
 
So my Yeti JR came today...

DSCN1085_zpsgpdkzeqd.jpg


I charged it up, drove it around on the carpet for a minute, and tore it down. My first impressions were about the same as everyone elses. First off, the battery door on the transmitter barely stays closed. It half way latches and will pop open and dump the batteries if you bump it. Second, the steering is awful. The servo itself (for now) returns to center but it's ridiculously weak. With the weight of the truck on the tires, it won't return to center and it will barely turn the wheels unless it's rolling. Any kind of low speed crawling is completely out of the question with this servo. Besides that, I see a TON of potential.

Haven't seen pictures of these items yet so I figured I'd post a few...

DSCN1087_zpsdtjqnu1c.jpg


DSCN1088_zpsh8povgvw.jpg
 
I called and spoke to someone a few minutes ago regarding my lack of steering. They said they would drop a new servo in the mail tomorrow, however, after reading this thread I suspect I should just get a better one.

I'm new to this so if anyone wants to guide me in the right direction, I would appreciate it. until then, I'll use the search function and try to gather as much info as I can.

Direct replacement = pretty much any 9 to 11 gram servo with a 21, 23, 24, or 25 tooth spline.

A couple of us tried Hitec HS-65MGs and both of our ESC / RX units died shortly afterwards. Honestly, that servo should have no effect on the other electronics but... *shrug* the results are what they are. Could it be the LiPos that we were also using? Maybe, but this truck is labeled and sold as 2S LiPo compatible so... yeah. Just be prepared to scrap the stock guts.

Bigger servos require the stock guts to be removed and replaced with better stuff. You can keep the motor. Nothing wrong with it. Replace the ESC with a Hobbywing QR 1060 and call it a day.

Couple guys going with the HS-85MG but it doesn't allow the use of the servo saver and needs a new link to connect between the servo and the steering because the stock one hits the servo and limits travel.

The Spektrum I'm using is the same one that comes in the ECX Ruckus and Torment trucks. It's bigger so it still requires a new ESC and receiver but it's waterproof and allows me to keep the stock servo saver and linkage and use the included longer servo horn to prevent the link from hitting the servo.

Heard back from Hobbico today. They are sending me new guts. I guess I'll add them to the pile of stock guts that I've replaced over the years.
 
I've been driving mine around the house the past two days and I agree that the servo is terrible but I think since the TT has smaller wheels it's less of an issue for me. Once I get this thing outdoors this weekend I'm curious how my opinions of the car will change. Either way I think the hs-85mg will be on order next week. Thanks for the gutted diff pics @jdurgin
 
The axles are like dogbones at the open diff. The side gears are part of the cup for the dogbone and they're plastic. The axle shaft is plastic and the end is molded to a hex. The axle is retained by that outer bearing that's held in place by a molded channel in both halves of the axle housing.

DSCN1089_zpsdr5y4rue.jpg


DSCN1091_zpsed2m7fm8.jpg
 
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