Kraton Spur gear issues?

[spence]

Hi guys, I replaced the spur gear along with the pinion, (robinson racing 14t mod 1 5mm shaft) and um yea, idk if its the cheap steel that the spur gears are made of, I set the mesh correctly with a tiny bit of slop, almost no slop at all. Tightened down the adjuster bolts.

Center diff was rebuilt with shielded bearings(not sealed) I usually use sealed bearings, but they are still ok.As well as the Hot Racing center diff mount that replaces the plastic one.


Idk why tho, the spur gear mesh is kinda loose now, and the teeth are folded over in one direction, this has happened twice, maybe 3 times...

There isn't any issue with it, it just really bugs me, because this takes out the robinson racing pinion gear as well by making it wear out fast.

I love running on 6s and thats all I run. These spurs aren't cheap, they are $20 a piece... Is this just the way the stuff goes? Idk if they are even steel, maybe some sorta zinc aluminum steel alloy... Eventually about to drop more doe on this thing, (savox 1210sg HV, new batteries, voltage hobbies servo mount)

Is this a part of life with this junky spur gear? I don't understand, this spur that was brand new, has maybe 1 or two runs on it... NO flex in the motor mount area

Idk part of this feels like a waste of time since I fear the bankruptcy of hobbico...

I put a castle bec into it, 3 hot racing diff cups, new v3 chassis that happened to be factory drilled for the outcast battery tray. Outcast battery tray, Hot Racing F+R chassis braces...

Basically rebuilt the truck from the ground up... Kinda makes me feel like I'm wasting money here because of the spur



Some insight on this would be appreciated
Thanks
-Spence

 

[Rtappy1985]

Had my kraton over a year and no issues with spur yet maybe u got a bad one tgats possibly out of round

 

[msmy300z]

I have had some issue with eating spur gears too. I went through several pinions and 2 spurs before I finally decided that the motor shaft was bent. My mesh would be spot on it one place and much further out on the other side of the pinion. I had no experience with a metal on metal drive train and I have had much better success after a new motor and shimming everything. There is still some wear on 6s but better than it was. I think 6s is just brutal.
It sounds like you have the hot racing diff mount but not motor mount?
I have seen mixed reviews on here about how well the motor mount holds mesh with just one bolt.
Any other experiences?

 

[spence]

I'm kind of confused as well, its possible the motor shaft could be bent, not sure though. I still think the spur could be of a better material(like a hardened steel of some sort) Is there a spur gear upgrade out there?

I just recently did A LOT of work to my kraton, I don't want to put it to bed, I wanna thrash it some more...

The kraton is such an excellent juggernaut overbuilt truck (especially the upgrades that I did in a few places) I don't wanna abandon it... I still gotta get a voltage hobbies servo mount, 1210SG HV, and a new set of two 3s lipos...

Arrma pinions are crap (stock) for the kraton, they don't even fit correctly on the shaft, the Robinson racing ones are a much nicer fit on there. I use MOD 1 RR gears...

 

[Megasty]

I have never had spur issues. My issues have always been with pinions, especially with larger pinions. Robinson Racing pinions are great & all but I've destroyed those too with the spur being completely undamaged. The hardness of the metal does not bode well with the spur. The spur is machined steel but is not super hard. I have found that the cheap 5 pack of pinions on eBay, the 11-15t & 15-19t are a great match. I seldomly break them but I just throw on another & bash on.

I also never tried the HR motor or diff mount. The GPM diff mount is dirt cheap & haven't let me down in any of my rigs. But I've heard too many bad things about that HR motor mount with the one bolt design.

Anyway when it comes to upgrades, if it makes another part fail, either upgrade that part or abandon the upgrade. That cheap China 15t pinion has been in my Kraton all last year & this year. In that time frame I've superman jumped it more than I can remember, speedrun it & bashed it on 8S, ran it through enough mud to fill a pool, had to fish it out a ditch, & gave it several snow baths. Most of that was done with the stock truck minus the pinion, the superman jumping & the 8S stuff. I don't upgrade my Arrma's too much. I just don't like the idea of upgrades causing more problems than solving. It's also just easier to upgrade what breaks since I have all the Arrma 1/8 cars.

 

[spence]

I have never had spur issues. My issues have always been with pinions, especially with larger pinions. Robinson Racing pinions are great & all but I've destroyed those too with the spur being completely undamaged. The hardness of the metal does not bode well with the spur. The spur is machined steel but is not super hard. I have found that the cheap 5 pack of pinions on eBay, the 11-15t & 15-19t are a great match. I seldomly break them but I just throw on another & bash on.

I also never tried the HR motor or diff mount. The GPM diff mount is dirt cheap & haven't let me down in any of my rigs. But I've heard too many bad things about that HR motor mount with the one bolt design.

Anyway when it comes to upgrades, if it makes another part fail, either upgrade that part or abandon the upgrade. That cheap China 15t pinion has been in my Kraton all last year & this year. In that time frame I've superman jumped it more than I can remember, speedrun it & bashed it on 8S, ran it through enough mud to fill a pool, had to fish it out a ditch, & gave it several snow baths. Most of that was done with the stock truck minus the pinion, the superman jumping & the 8S stuff. I don't upgrade my Arrma's too much. I just don't like the idea of upgrades causing more problems than solving. It's also just easier to upgrade what breaks since I have all the Arrma 1/8 cars.

I have the HR diff cups (all 3) HR chassis braces, the center diff brace, and many other upgrades. Stock motor mount. So you are saying the stock china pinions are better in terms of health for the spur? I think I'm gonna check out the motor shaft as well.

I still am nervous about arrma and axial going away. When I get the money, I'll get another spur and stock pinions, and maybe run this spur and pinion till they blow.

I just hated how the stock pinions don't fit too good on the motor shaft(loose fit causes out of round pinion) I love running 6s, thats all I run and I beat the hell out of it haha...

So where should I get those pinions? I found a 14t is good in terms of speed for the pinion... Hopefully I can get this crazy monster working good for a long time...


I am a perfectionist and I don't like how my new $20 spur has folded over the teeth and aren't wearing decently straight, I guess as you said its due to the robinson racing gear being too hard and kinda messing with the soft spur...

 

[Megasty]

I have the HR diff cups (all 3) HR chassis braces, the center diff brace, and many other upgrades. Stock motor mount. So you are saying the stock china pinions are better in terms of health for the spur? I think I'm gonna check out the motor shaft as well.

I still am nervous about arrma and axial going away. When I get the money, I'll get another spur and stock pinions, and maybe run this spur and pinion till they blow.

I just hated how the stock pinions don't fit too good on the motor shaft(loose fit causes out of round pinion) I love running 6s, thats all I run and I beat the hell out of it haha...

So where should I get those pinions? I found a 14t is good in terms of speed for the pinion... Hopefully I can get this crazy monster working good for a long time...


I am a perfectionist and I don't like how my new $20 spur has folded over the teeth and aren't wearing decently straight, I guess as you said its due to the robinson racing gear being too hard and kinda messing with the soft spur...

The stock pinion is garbage. I broke the stocker on my V2 Outcast on its 1st 6S run I usually get the pinions on Amazon:

https://www.amazon.com/gp/product/B07429FZQR/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

These pinions are machined as well & get the job done.

 

[spence]

The stock pinion is garbage. I broke the stocker on my V2 Outcast on its 1st 6S run I usually get the pinions on Amazon:

https://www.amazon.com/gp/product/B07429FZQR/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

These pinions are machined as well & get the job done.

Cool thanks man. I really hope arrma doesn't go out of business, what do you think? Like current stage of the lawsuit? Axial as well. Kinda curious what you guys think about that matter tho, cause I'm kinda worried... There aren't a ton of spur gears available...

 

[Hunter Reynolds]

Why would they go bankrupt? I have perchased a kraton, how is this going to effect long term parts support? im lost lol

 

[Megasty]

Arrma & Axial isn't going anywhere anytime soon. They are not listed under Hobbico's chap 11 restructuring & are not up for sell ATM. Arrma has always handled their own business outside the states & only used Hobbico stateside for distribution & warranty purposes. Axial actually always handled everything in-house & only recently let Hobbico deal with distribution but they now handle that west of the Mississippi again since Hobbico closed that distribution center.

 

[spence]

So guys, I think the RR pinion gear VS spur gear battle, I think the robinson racing pinion gear is losing LMAO I think its softer than the spur! The spur is a tad beat up, still gonna buy a new one, but the pinion is destroyed, its all pointy and thin and very sharp lol geeze... The spur is file hardened while the Robinson racing gear is soft via the file test! So what does this mean? Will those amazon pinions work ok? The robinson racing pinion is destroyed!!


The pinion is hard, but not as hard as the spur! Idk this is interesting findings for sure lol no wonder my gear mesh keeps moving, I made sure my current STOCK motor mount that I have been using since I got the truck was tight, the hot racing piece replaces AR310348, or the diff truss that is usually plastic... I don't have the single bolt HR motor mount that is pointless...


I mean its a Mod 1 pinion thats correct right?
Look at the videos!

Pinion

Spur

I went full Ave on this one

I have a collection of old RR pinions and stock pinions I broke the teeth off of too
Motor shaft appears to be a ok.

interesting, the stock pinion that broke is harder than a RR gear a lot of head scratching going on here... You guys for sure think I will be happy with those amazon pinions?

 

[jrwalte]

maybe you have your initial start punch setting set too strong?

 

[Megasty]

There's an innate problem with hardening steel. While the process works wonders if done right, the opposite results occur if done wrong. Heating up a metal too much can cause the molecular structure of the metal to swiss cheese. Heating it up too little will not align the molecules enough so they will look like a jumbled mess. Both events will result in a metal that is weaker than what you started off with. Plus you have to adjust your temperatures for the combination of metals you're using. One heat doesn't cure all, albeit 2 in this case. Quenching also plays a large role in the final product. Quenching is even harder to explain because there are just too many ways to do it. But it leaves the metal frozen in state. Some methods add a protective layer through thermomolecular bonding.

Needless to say, hardening isn't an exact science. I'm leery of all hardened products because of this, having worked in that metallurgy environment for over a decade. I'll even harden my own sintered parts, which is a much easier process because you can only burn them up & do not have to worry about making them weaker.

 

[spence]

There's an innate problem with hardening steel. While the process works wonders if done right, the opposite results occur if done wrong. Heating up a metal too much can cause the molecular structure of the metal to swiss cheese. Heating it up too little will not align the molecules enough so they will look like a jumbled mess. Both events will result in a metal that is weaker than what you started off with. Plus you have to adjust your temperatures for the combination of metals you're using. One heat doesn't cure all, albeit 2 in this case. Quenching also plays a large role in the final product. Quenching is even harder to explain because there are just too many ways to do it. But it leaves the metal frozen in state. Some methods add a protective layer through thermomolecular bonding.

Needless to say, hardening isn't an exact science. I'm leery of all hardened products because of this, having worked in that metallurgy environment for over a decade. I'll even harden my own sintered parts, which is a much easier process because you can only burn them up & do not have to worry about making them weaker.

So, I mean like would you definitely say getting those amazon pinions should fix my issue? Maybe as well turn down my start punch too? Hardening makes metals inherently brittle. Those pinions you linked tho are 32 pitch gears aren't they MOD 1?

 

[Megasty]

So, I mean like would you definitely say getting those amazon pinions should fix my issue? Maybe as well turn down my start punch too? Hardening makes metals inherently brittle. Those pinions you linked tho are 32 pitch gears aren't they MOD 1?

I was just about to buy some too but the seller changed the listing. I contacted him & he's out, he has to import more. He sells on eBay too & the dropshipper is out too, so no more US pinions for a few weeks. So i'll just order these:

https://www.ebay.com/itm/M1-5mm-11T...961780?hash=item1ed1beceb4:g:yQUAAOSwYwJZ558q

It's where they get them from anyway, then up the price for convenience.

Anyway, the 13t pinion in my Siren MT just broke, It had exactly 37 packs on it. From the looks of it, it's sintered hardened & CNC'd just like the RR gear - for a fraction of the price. My last RR gear lasted 4 packs

 

[nulli]

A spur costs more so you'd ought to like it to last... plus it's a hassle to change one.