Axial 1/18 Yeti (and Yeti Score)

[OldNTired]

Just out of curiosity. Has Axial made any sort of comment about the poor quality of these new Jr. RTR's electronics? It just seems that these vehicles have a far higher failure rate than any other RTR I've seen released. There are typically a few bad eggs in a batch but this seems pretty far reaching.

[monkeyracer]

Originally Posted by Brake Weight

That's a 280 size can. The specs on Axial's website say it's a 380.

Just to clarify for those looking for a new motor on these.
The stock 380 Motor is Ø28mm x 40mm can Length.

If you are looking for motors to fit this, look for Ø28mm sized motors.

For a brushed motor, this is going to typically be labeled as 380, but keep in mind some motors are actually more like 380 XL, like the Traxxas Titan 380, which is 28mm in Diameter, but longer than 40mm long. You may see something listed as 400 size, or 370XL, or something similar. Look at the motor dimensions. They will give you diameter and can length. If they are similar to the stock motor, it will probably work.

For a brushless motor, they typically list the dimension as the size of the motor. For example, a 2850 motor is 28x50 or 28mm diameter x 50mm length.
The Traxxas motor posted a few posts back (VXL 380) is a 2848 size - Ø28mm x 48mm long.
Most 1/18 scale brushless set-ups I've seen are smaller can diameters, like 2040 or so typically. These should still work, but they won't be able to produce as much power as the larger 28mm diameter motors.

One other thing to consider is number of turns or KV (covered in other threads, but will touch on here)

A brushed motor will be listed with number of turns - The stock motor is 40 turns. This is the number of times the wire is coiled around the each stator arm inside the motor.
The higher the number, the slower the speed, but higher torque (good for crawling).
The lower the number, the higher the speed, but lower torque (good for go-fast racing).
Most ESCs will have a limit on the minimum # of turns that you can use, so check that with the ESC you will use. The stock ESC doesn't list that (that I could find) so I would stick with something around the same number of turns as the stock, otherwise, you will need a new ESC.

A brushless motor will be listed as kv. This means for every volt of electricity, you multiply the kv number to get the RPM.

So, a 4500 kv motor on 2S lipo power is going to max out at 37,800 RPM (at 8.4V) and typically run at around 35,000 RPM (at 7.4V). The same motor on 3S lipo would be almost 50,000 RPM max.
A high KV motor will be faster, but have less torque. Vice Versa for a low kv motor.
The ESC may have a limit on the max RPM or max KV that it supports, so check that when you are shopping.

[Brake Weight]

Right on. I've got a 2838 3600kV I'm going to try. I've got multiple pinions to try out, too.

Not mentioned is the way this motor is mounted. Depending on the pinion size, it can allow the motor to rotate further to the outside allow a longer can.

[Exiwolfman]

got this Traxxas servo on order and two lipo 2s 35 coming , any idea if that servo will fit ..I'm take a gamble since truck not here yet ....It's waterproof and cheep and figured if it works well in a Revo mini why not in the yeti .


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[SCREAMER]

Comparing the dimensions to what I just put it mine it'll be a little deeper and wider. It looks like it'll fit but it'll be closer to the center shaft and a bit wider. It's cheap, 41oz/in, and waterproof. Looks good.

[Lavaheadache]

I have that servo and briefly dropped in the spot. The wire comes out the back of the servo which immediately turned me off to using it in this application cause of the center shaft

[Brake Weight]

I just put a cheap mg90 in and it fit like a glove. Pulled the motor and attempted to put a 2838 brushless and it doesn't work that well. The motor mount is an issue. The holes had to be drilled out to accept an m3 bolt. Then the little 10 tooth pinion is for a smaller shaft and counter sinks into the mount itself. The smallest 3.125 I've got is a 15 tooth and it ain't fitting. The area where the set screw goes counter sinks into the motor plate. Other than needing the tapered head 10mm m3 bolts and not having a pinion that would fit in the hole, it would've worked.

Stock configuration. Someone needs to address this and take my money.


So I dug out this old Losi combo. It's a 24mm can and I had doubts about the power.


This smaller motor has the proper size shaft for this 10 tooth pinion. While buttoning the chassis back up I stripped two bolts already. I just so happen to have several bags of these m2.5 bolts and some the proper lengths. They don't have the button heads, though.


I will say this. I am surprised at the amount of power put out by this little 24mm motor. It cogs like damnit being unsensored and 4500kV. But in my garage will do standing backflips when it catches.

I'll be looking for a motor in the 2000-2500kV range or figuring out how to make the larger 28mm motors work.

[Brake Weight]

Someone handy with a lathe that can turn out something like this? Or a 3D printed one may hold up in his scale.

[Lavaheadache]

I assume we will see a metal motor plate soon enough. I would like to see a 2 piece upper stay to make adjusting the pinion mesh a bit easier. I look forward to seeing Hot Racing do their thing with these little tikes.

[TownsendTdi]

Originally Posted by Brake Weight

I have that motor in a mini 8 and it hauls, it's a lot heavier too. I was hoping to put my spare motor in the Jr. Thanks for the pics

[Brake Weight]

Originally Posted by TownsendTdi

I have that motor in a mini 8 and it hauls, it's a lot heavier too. I was hoping to put my spare motor in the Jr. Thanks for the pics

I don't know how much smaller a pinion is made for this shaft, but I will be looking today. I also noted the spur setup was odd. There's no slipper and the plastic shafts are flexy and I'll assUme are that way to take some of the shock loads out of the drivetrain. The spur has a bearing on one side and nothing on the other. It's also held on with a pin. Once some slack is worn into the immediate area it'll fail.

Axial left several areas for improvement: motor mount, spur gear area, bulky and unnecessarily heavy battery mount, and there seems to be some binding in the steering on mine.

[Lavaheadache]

Originally Posted by Brake Weight

I don't know how much smaller a pinion is made for this shaft, but I will be looking today. I also noted the spur setup was odd. There's no slipper and the plastic shafts are flexy and I'll assUme are that way to take some of the shock loads out of the drivetrain. The spur has a bearing on one side and nothing on the other. It's also held on with a pin. Once some slack is worn into the immediate area it'll fail.

Axial left several areas for improvement: motor mount, spur gear area, bulky and unnecessarily heavy battery mount, and there seems to be some binding in the steering on mine.

I had binding in my steering too. It was the very tight fitting ball cups. I used a sharp hobby knife to trim some of the inner lip that causes these things to be almost impossibly hard to snap on. I had to do the same thing to my shock links and trim off excess mold material on my A-arms. Honestly these things got released in rough shape. My shocks even get stiff after a few minutes of inactivity, just like my stock scx10 shocks did. You have to give them a quick compression before you drive to wake them up.

[Brake Weight]

My look over last night wasn't too thorough. After things settle down holiday wise I'll go back through it and shave some of the steering components until its smooth. The 4500kV motor is a bit much and I'll order that brushed ESC linked a page or so back. I've got the bigger version of that one on my scx10 and it's nice. It does like to roll a lot and after 2-3 walks of shame I grow tired of it.

[TownsendTdi]

Originally Posted by Brake Weight

I don't know how much smaller a pinion is made for this shaft, but I will be looking today.

I've got a 9t, haven't seen any 8s.

[Brake Weight]

Originally Posted by TownsendTdi

I've got a 9t, haven't seen any 8s.

I wouldn't think they'd get much smaller. Maybe some of the Dromida guys can pitch in.

I've made a few laps up and down my driveway and it makes giggles at speed, but stays upside down maybe 30% the time or at least rolling.

I don't think it can handle a 28xx BL motor. I've decided to go back brushed until the aftermarket catches up.

[Poprivet]

Well, like the rest, my electronics crapped out the second after i put a lipo in it. I never even hit the throttle. The second i touched the steering it went down unresponsive.

I have a mamba micro x/ 4100kv, but thought I'd see how the stock motor would do on 3s.

Luckily i had everything i needed in a drawer to make this thing awesome.
Rc4wd 1.55 racelines- i won at ecsc this year
Hs-5245mg- left over from a dig setup i removed
Titanium turnbuckles- from an rc18t turned rc18r
Ae-5- from my bomber (now sold)
380 size heat sink- someone gave to me. Slotted for cooling vent.
Spektrum sr3100 rx- i always have a couple extra rx, just in case.

I had to make a little bracket to mount the servo. I hate cutting up a new chassis. The bracket was pretty simple to make. Im using a stock wraith servo mount on the other side.

I just accidentally deleted all 55 photos of the progress. So here are some crappy ones after everything was already installed.

Heat sink, because i had it and they never hurt. You can kind of see the slots i put in to open up the vent hole in the motor.


Turnbuckles, the toe in up front was excessive. I plan on ordering a complete titanium turnbuckle set for the rc18t. That should be enough to titanium adjustable the rest of the links.


The servo, i had some great pics of the bracket i made, but...dammit. I can pull it back apart and take some better pics if anyone wants to see them.
Stock wraith mount on the left side (edit: with spacers), all the way back in the slotted hole, and my bracket to offset the front mounting hole about an 1/8"


Ae-5, already had the stock bullets, so no soldering required. Servo taped to the top of the servo. Rx servo taped to the side of the esc heat sink.


Wheels, i toaster ovened the stock wheels and tires. Be careful though. 10min. At 300° started to melt the wheels, but was just enough time to separate the tires.



Had to put in a m3 cone washer between the wheels and the hex to keep the wheels off the knuckles. The wheel hex is a little deeper than the front hex. The wider hex in the rear had no issues.


I've ran two 1300mah 3s packs through it so far with no issues. Motor and speed control barely brake 100°.

With 61oz. @ 4.8v the steering is excellent. 3s power brings this thing alive with stock gearing and no heat issues. This thing is an absolute blast to drive now.

[Lavaheadache]

Surprisingly this plastic drivetrain is up to the task of brushless lipo power.

[SCREAMER]

Got my replacement ESC in. Took advantage of an Amain coupon and free shipping so it only ran me $35. Overkill for sure but it's small and waterproof, switchable 3amp BEC for 6v or 7.4v, good for 2s or 3s, and many other programmable features with the included card. I've wanted to try one of these new Hobbywing 1080 ESCs for a while and this was the perfect application for me. I have everything I need now to get her running except for a servo horn. I'll hit up the LHS as soon as these holidays blow over and get this thing in the dirt where it belongs instead of on my bedroom dresser.

[Brake Weight]

That ESC is a little big.

They have a smaller one that is 3s capable but doesn't have the programmability. It's the one I was thinking of ordering. I have one like yours on my scx10 and it is great so far.


http://www.hobbywing.com/goods.php?i...5635.0.0.0.0.0

[TrilloThrillo110]

Originally Posted by Brake Weight

QuicRun WP 1625 Brushed_Car System_HOBBYWING | Welcome to Brushless System Trends -

Might have to order me one of those once the Christmas break has blown past