Fallen's Yeti Jr.

[Fallen]

Not really, but that's because I haven't researched any yet.

Some of the things that have kept me connected to this rig, are how cheap and reliable it is. So any brushless system would need to check those boxes; cheap & reliable. I already have some extra RX/TX set-ups I can put in.

[Fallen]

Alright, I think I'm going to try out the Dynamite brushless 380 motor/esc in one, DYNS0501.

My hobby shop has them in stock, and I have to stop by there anyway. One of my Yeti Jr's front drive shafts finally failed. After over two years of driving in the sand, dirt and rocks and being played with by two 3 year old boys, a part finally failed.

My LHS ordered the shafts for me, and since they're in I plan to get them and the motor tomorrow.

I also recently scored what I suspect was the last available Yeti Jr. Score front bumper & body mount set. This bumper certainly works and looks better with my Mini body. I might also be able to combine the body mounts with some Tamiya odds and ends to attach the body in a way that makes battery changes more simple.

[Fallen]

Here's how she currently sits:



I feel like I got super lucky! DRED805 sent me his old Yeti Jr. Trophy Truck, filled with Axial aluminum mods. I swapped the trophy wheels/tires and body onto my old Yeti Jr. chassis. My 3 year old sons LOVE it, and one of them usually sleeps with it. I've let them drive it, on the 50% throttle setting and they're starting to figure it out. They don't really care if they haven't figured it out yet though, they just love doing anything with it.

The chassis DRED sent me which has all of the upgrades sits like this currently:



Empty. Having so much aluminum goodness in this thing, I wanted an electronic system that could do it justice. I bought a Castle Mamba Micro ESC and a Castle 5300kv sensorless motor to give this thing the power the aluminum upgrades were built to withstand.

Unfortunately, Castle electronics are great at finding weak spots, and they didn't let me down. The center driveshaft that sends power to both the front and rear wheels is plastic from the factory. The Castle system made short work of that.

Also unfortunately, the only company who makes an upgrade for that is GPM. I don't like GPM because **** China. Nonetheless, I've got one on the way, but it'll take a month to get here.

So she sits empty for now. Waiting on the one part that will bring her back to life, and back to terrorizing the dirt in my front yard.

Once it's all back together you'll see a bit more of it, as those beautiful King shocks look great under the blue Mini Cooper body.

[DRED805]

Reunited with it's old MTZ's!... haha. I'm glad the kids like it so much!

[Fallen]

Apparently they were destined to be together.

When I installed the wheels / tires onto the chassis, it jumped for joy around my house for 2 hours. And that was with no battery!

The little bit of beach driving I got to do was great. The aforementioned electronics with these MTZs and its a blast in the sand. And the electronics don't overheat.

[Fallen]

By the way, do you remember what shock oil you ran in these King shocks? I put some 20wt in the rears, but they're still too fast. The fronts seem fine, so I haven't fiddled with those.

[DRED805]

Originally Posted by Fallen

By the way, do you remember what shock oil you ran in these King shocks? I put some 20wt in the rears, but they're still too fast. The fronts seem fine, so I haven't fiddled with those.

Probably leftover axial 30wt.

[Fallen]

Sounds about right, 30wt is what I planned to pickup and try next. I usually do the same thing, which is start with whatever oil I happen to have laying around and go from there. I only have Tamiya yellow, and 20wt TLR oil at the moment. I think the Tamiya yellow is close to 30wt, so hopefully I have enough to save myself a trip the the shop.

[Fallen]

Well finally, the center driveshaft came and got all built up. This thing sits in the bottom, center of the chassis and the car is basically built around it.



It was supposed to take a month to arrive, and the boredom was killing me. So much so, that I did what I know shouldn't be done: paint plastic parts. They always get scraped up and look horrible, but boredom will drive a man to do unspeakable things:







The cage pieces, A-arms, axle housing, trailing arms and front bumper were painted with Krylon Fusion Metallic Dark Gray. It doesn't look that different from the stock gray, which I'll appreciate once it starts chipping off.

Thanks to the RCCrawler search function I found a bunch of info on solving the leaky shock problem. Those rear Kings were super leaky, like lose 1/3 of their oil every battery. I greased the O-rings, and replaced the spacer between the rings with a Tamiya O-ring. Then I Teflon taped the upper and lower caps. Leaks solved (so far).

I mentioned earlier how Castle electronics really don't like plastic drivetrain parts, and will basically seek and destroy them. This chassis came to me with both differentials locked. I planned to drive it as a go-semi-fast rig, so I opened the front using the stock differential which is plastic. The 5300kv motor turned my Yeti Jr. into a 2wd truck, as it shredded the gears on the long output side of the diff.



It took me several tear downs to find it, as the teeth looked fine, and the differential performed normally, until both front wheels were making contact and needing to lift the truck. Then it was like the front wheels had a loose slipper clutch and wouldn't spin. Since an all metal drive train is required, back to the locker in the front I went.

So this is how it sits now, as pictured crawling around in front of my condo:







Since both differentials are now locked, I intend to run this more as a crawling / trailing rig. I ordered a Holmes Hobbies V2 380 Revolver to mate up with my Mamba Micro ESC.

The Axial aluminum upgrades really remove a lot of the slop in the front suspension. My Yeti Jr with all of the stock plastic parts has a ton more slop, which my 3 year olds don't mind. It surprised me how big of a difference these upgrades made.

With this body and wheelset, it's more like a 1:10 short wheelbase Gambler 500 type of vehicle, than a 1:18 rock racer. Oh well, I really like the curves of this Mini body and how it looks geared for offroad.

I don't know if you noticed, but the price on these Yeti Jrs went up from $150 to $175. Apparently they're pretty popular still, so hopefully production continues for a while.

My 3 year old sons still usually sleep with one of these.

[durok]

Awww...

MAN!

This is so nifty...

My favorite stuff is when people go way outside the lines like this.

Did ya use cut up tires for the fenders???

It looks like a British Trials car...

Nowhere as capable as this thing looks to be, but I ran HPI Super rally wheels and tires on a Tamiya M-03 Mini that I covered with a VW New Beetle body with the fenders cut off, used to run it at a groomed off road track many years ago - was hilarious.

Awesome build!

[Fallen]

Thanks, and yeah, they're Tamiya tarmac tires cut up and glued to the body.

It's been an odd-ball build for sure, but it's really cool now and I enjoy how unique it is.

I ran it at a baseball field earlier today when my family and I went to a park. As a go-fast rig it's pretty fun. Even with the 5300kv motor electronically limited (via TX endpoints) to 75%, it can't handle its own top speed. But it sure is fun to drift around in silty dirt. Watching the suspension handle bumps is satisfying too.

What bug body did you fit on an M03 chassis? I'd love to drop a bug body on this, and I think the M03 and M05 wheelbase is similar.

[soze]

Dammit... I don't even know where to begin. I've been eyeing a can-am for a while now, and finally picked one up. Looks like you've the the TT/RR version. Time to go through your thread and see what's necessary! LOL.

[Fallen]

Mine started out as the Can-Am version. I replaced the front bumper with the one from the old trophy truck version.

My opinion is that the necessary upgrades are replacing the entire drivetrain with steel or aluminum. Most of it is plastic from the factory, and even the stock electronics will overpower that stuff. A locked rear differential is also something I really recommend, as well as some type of servo saver delete.

Those upgrades being done have made this truck a very reliable and fun truck to play with.

[DRED805]

Looking good!... Glad the truck went to good use!

[durok]

Originally Posted by Fallen

Thanks, and yeah, they're Tamiya tarmac tires cut up and glued to the body.

It's been an odd-ball build for sure, but it's really cool now and I enjoy how unique it is.

I ran it at a baseball field earlier today when my family and I went to a park. As a go-fast rig it's pretty fun. Even with the 5300kv motor electronically limited (via TX endpoints) to 75%, it can't handle its own top speed. But it sure is fun to drift around in silty dirt. Watching the suspension handle bumps is satisfying too.

What bug body did you fit on an M03 chassis? I'd love to drop a bug body on this, and I think the M03 and M05 wheelbase is similar.

It was the HPI New Beetle, long since discontinued...

[Fallen]

Man, this Holmes Hobbies 380 motor is prime time! At 2000KV its still too fast for this little guy, but it also has excellent low speed control. In the low speed arena, it feels very similar to my brushed Yeti Jr. Currently geared 18 / 60.



The install wasn't exactly a drop in, but pretty simple. I had to use some washers between the motor plate and the motor to push the motor aft in the chassis. That's because the shaft is too long for stock mounting. Hehe, something that came from John Holmes with too much shaft... maybe someone will get that reference.

I also had to swap out the bullet connectors as it came with 4mm bullets and I needed 3.5 to match the Mamba Micro. I don't have a soldering station in my 2 bedroom condo that I share with a wife and 5 kids, so off to the hobby shop I went.

While this is likely the end of significant mods for my brushless Yeti Jr, I did score a killer find while at the hobby shop...





While the shop guys soldered my motor I cruised the shelves and found a body for the Tamiya M Chassis. I was so excited, I didn't even care what body it was, I was buying it. At the counter I found out it's a Honda Civic, so for my brushed Yeti Jr, a Civic rally body is now in the making.

It'd probably be easier to just go buy an 1/18 scale rally car, but that'd be no fun. If I did that, I'd probably want to turn the rally car into some sort of UTV, like a Can-Am or something weird.

[DRED805]

That's a killer motor/esc combo!

[smog]

You are selling me hard on the Jr. I have been wanting one of these for awhile.

That really is a sweet little power plant you’ve got in there

[Fallen]

Thanks, and yeah, it really is a rad combo. The torque is off the charts, and the top end is more than the Yeti Jr. can handle, even with modest gearing.

But you can still crawl with it since the low speed control is there.

Forgive my newbness as this is my first Holmes motor, but if I ever upgrade electronics again his website will be my first spot to look. Having a $100+ electronics system in what was a $150 rig seems a bit ironic, but having done these upgrades over about a 3 year period makes me feel a bit better about it.

The other change I had to make from stock for this motor is that the Holmes 380 has a 3mm shaft, and standard 380 motors have a 2.3mm shaft. So standard 380 size pinion gears won't fit, but that's an easy fix and it makes finding pinion gears much easier.

[Fallen]

Thanks to the Yeti Jr upgrades thread, I found these:

https://www.subotechrc.com/home/376-...car-parts.html

They look like a metal front differential alternative. I ordered two, and will post up with results as to whether they fit or not. Unfortunately, I'm pretty sure these are coming from China, so it could take a while for me to be able to test them out.

I'm hoping they can allow me to run an open front diff, due to the metal gears that MIGHT stand up to brushless power.

I'd really rather run my Yeti Jr as a go-fast rig, than a crawler. I have this mental block about a locked front diff, that I just can't haul ass and feel good about it.

So hopefully they:

1. Arrive from China.

2. Fit.

3. Are decent enough of an alloy to survive brushless power on loose dirt.