Kraton 4s motor/esc upgrade - what else at same time?

[pierre1111]

Stock kraton 4s (4408v2)

I want to try a sensored motor so I have a max8/4268 combo coming.

Are there any other tweaks/upgrades I should do while it’s apart?

I’ve read that the slipper clutch is a weak point. I haven’t had any issues with it yet but it’s still young… maybe 8-10 runs through it. Trying to find info if a differential from another model or version is swappable but it’s hard to tell what applies to my specific version.

 

[MrTitanium]

The 4s line has metal sintered diff gears. In other words, cheap Chinesium.

I would highly recommend buying either the Arrma steel CNC units or the HR spiral set.

Nothing wrong with the slipper IMO.

 

[Barmaleus]

The 4s line has metal sintered diff gears. In other words, cheap Chinesium.

Are all of them chinesium? Meaning the center diff (on v2.5) as well? Are the input gears also chinesium?

 

[morrjr71]

The most important sintered gears to change to CNC steel are the ring and input pinion gears on the diffs. These are the ones that are most prone to stripping and wear.

Arrma used to make their own CNC steel-geared transmission modules, but they were discontinued quite a while ago. I have them in both my Typhon 3s and my Infraction 3s (the Infraction is set up to run 4s on occasion). The CNC modules weren't cheap - $75 each - but they are durable.

 

[Barmaleus]

@morrjr71 Understood, thank you!

 

[pierre1111]

So… the adventure continues. The 4268 motor was too big. The driveshaft, while still, does not rub. After it’s initial run it’s clear it did at speed though. Paint transfer on the shaft and a tiny groove worn into the motor. The sensored difference was fun though and didn’t want to give up on it.

The shaft bearing support looked odd in this model. It only supports the bearing on the side opposite the motor. And it’s not removable, it’s molded into the chassis. I dremeled the support off so the chassis is flat and used the Arrma support that fits in the honeycomb and captures both sides of the bearing. That didn’t help, there’s still enough slop in the shaft for it to touch the motor.

I’ve read a few threads saying this will work. One mentioned a 15t pinion… stock is 13t. Higher pinion tooth count = larger diameter = bigger motor to shaft clearance.

I’m going to switch to the 4278 which is 2250kv vs 4268 that’s 2500kv. This will allow me to run a 15t pinion and remain at about the same rpm. Also going to the hot racing aluminum shaft. Hopefully that will put an end to the rubbing.

Oh why not … let’s swap from slipper to a center diff while we’re at it.

 

[Glitch]

So… the adventure continues. The 4268 motor was too big. The driveshaft, while still, does not rub. After it’s initial run it’s clear it did at speed though. Paint transfer on the shaft and a tiny groove worn into the motor. The sensored difference was fun though and didn’t want to give up on it.

The shaft bearing support looked odd in this model. It only supports the bearing on the side opposite the motor. And it’s not removable, it’s molded into the chassis. I dremeled the support off so the chassis is flat and used the Arrma support that fits in the honeycomb and captures both sides of the bearing. That didn’t help, there’s still enough slop in the shaft for it to touch the motor.

I’ve read a few threads saying this will work. One mentioned a 15t pinion… stock is 13t. Higher pinion tooth count = larger diameter = bigger motor to shaft clearance.

I’m going to switch to the 4278 which is 2250kv vs 4268 that’s 2500kv. This will allow me to run a 15t pinion and remain at about the same rpm. Also going to the hot racing aluminum shaft. Hopefully that will put an end to the rubbing.

Oh why not … let’s swap from slipper to a center diff while we’re at it.

Good ideas. I’m pretty sure you’ll fix the issue with those mods.