Stripped pinion gear

[Micstar]

Heat it up, arrma loves red loctite. I believe they can handle 6s just not the arrma pinions. I bought some advantage racing pinions and have not broken any and usually only run 6s

Yep I am with @Stopfer I have changed to a Robinson Racing pinion and so far so good??

 

[Kpsnuts]

I've contacted Arrma regarding this issue - have they any plans to resolve the issue.

Also have people shimed, used heavier weight diff oil and meshed well and still get the issue?

My plan is to do all of the above - hope fully this resolves the issue.

Ive ordered the Robinson Racing Pinion. What Spur are people running there RR pinion with?

 

[Micstar]

I've contacted Arrma regarding this issue - have they any plans to resolve the issue.

Also have people shimed, used heavier weight diff oil and meshed well and still get the issue?

My plan is to do all of the above - hope fully this resolves the issue.

Ive ordered the Robinson Racing Pinion. What Spur are people running there RR pinion with?

I had to change the brushless motor due a breakage (see previous posts for details) and then also used a RR 14t pinion and have run 6s without any issues since.

 

[Kpsnuts]

I had to change the brushless motor due a breakage (see previous posts for details) and then also used a RR 14t pinion and have run 6s without any issues since.

Thanks for that - I will do the same - I was going to do the shimming and gear diff oil anyway......so will do those aswell.

Did you upgrade your spur.....I have a slight concern that you have a harder steel going onto the arrma steel spur

 

[Micstar]

Thanks for that - I will do the same - I was going to do the shimming and gear diff oil anyway......so will do those aswell.

Did you upgrade your spur.....I have a slight concern that you have a harder steel going onto the arrma steel spur

No problem so far, I really believe the main issue was the pinion but shimming and oil will definitely help.

 

[Kpsnuts]

Getting a Robinson Racing Pinion in the uk is like finding money in your pocket! Instead I have found RW pinion - Once I have installed and tested I will update this post.

 

[Voltron7]

Getting the gear mesh correct and keeping rocks out of the chassis was all mine needed. Have been on the same (new) 14T Arrma pinion and 6S for a long time now. Have also had success with the RR 15T pinion.

 

[nulli]

I had to use a modified puller to get the stock 12t off (and tear the alu servo horn to get the screw out). Just in case someone from Arrma is reading: PLEASE DON'T USE THE F***** RED THREAD LOCK!

On the third pack (first 6S run) with the 14t pinion one tooth went missing, happyhappyjoyjoy.
Should I use two strips of 0.1mm paper instead of one to adjust the mesh?

Using only one strip leaves a 'pleasant' non-binding gap but hey correct me if I'm wrong!

 

[Voltron7]

I had to use a modified puller to get the stock 12t off (and tear the alu servo horn to get the screw out). Just in case someone from Arrma is reading: PLEASE DON'T USE THE F***** RED THREAD LOCK!

On the third pack (first 6S run) with the 14t pinion one tooth went missing, happyhappyjoyjoy.
Should I use two strips of 0.1mm paper instead of one to adjust the mesh?

Using only one strip leaves a 'pleasant' non-binding gap but hey correct me if I'm wrong!

Agree but I've found the factory red compound is no problem if you heat the grub screw first, with your iron for about 30-60 seconds.
For mesh, I used 1 piece of standard copy paper and it is holding up, HTH.

 

[jk420]

Lol just lost every tooth on the stock pinion running 6s on pavement. I had the backflip tires on when it happened. I’ve pulled the motor and messed with the spur mesh before and never had an issue until I was doing speed runs with my new batteries lol. I feel smc batteries have such a punch and the backflips have suck bite that it just rips the teeth off. Lmao and I had just put it back on. It very well could have been my fault no getting the mesh right but I thought it was good. Oh well such is life.

 

[Kpsnuts]

Good info with the use of the solder... when I get round to doing my pinion.

I got some rubbish response from Arrma re the pinion "we always look to improve, we haven't had issues like this reported before.... thank you for your info.... we always look to improve our products" disappointing imo.

 

[slick2500]

Good info with the use of the solder... when I get round to doing my pinion.

I got some rubbish response from Arrma re the pinion "we always look to improve, we haven't had issues like this reported before.... thank you for your info.... we always look to improve our products" disappointing imo.

You should link to this thread

 

[nulli]

If you run 6S avoid the stock pinions. First 6S run, both lost a tooth plus considerable wear. I switched to Arrowmax and it is an improvement!

Agree but I've found the factory red compound is no problem if you heat the grub screw first, with your iron for about 30-60 seconds.
For mesh, I used 1 piece of standard copy paper and it is holding up, HTH.

It's not very nice when it's been splashed between the shaft and the pinion. Screw came off relatively easy.

I talked to an experienced shop keeper and he set's them up so that there's (almost) no play between the closest point where the pinion and spur teeth meet. With the small 12t etc pinions it's important to keep the contact area as big as possible regardless of the noise.

 

[Sully_]

Will this https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXDZEY&P=7 fit on the stock Kraton motor with the stock SPUR ?

 

[slick2500]

Will this https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXDZEY&P=7 fit on the stock Kraton motor with the stock SPUR ?

No, that gear is 32p you need mod 1. Robinson Racing RRP1213 would be 13t https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXURS8&P=7 if you want a different tooth count just replace the last two digits with the number of teeth you want, ie a RRP1214 would be 14t RRP1215 is 15t ect.

 

[Sully_]

So far iv been through 2 pinions. The 12t that came stock lost a couple of teeth and the 14t one that came extra with the kit got completely destroyed. I can almost guarantee that both times it was a rock that got caught up in the gears. When i lost the 14t i also lost teeth on the spur gear as well. Have a Robinson Racing 13t on its way with a new spur gear. Also have a dusty motors on its way to hopefully prevent me from blasting through pinion gears

 

[slick2500]

I think I'll just pick up some pantyhose for mine. Or a shower cap.
I found this in a quick Google search, might pick up a pair https://www.aliexpress.com/item/Hua...lgo_pvid=7df2c2ec-3d6b-4144-b3d4-5ec2a04d5177 wish they had a color other than blue though.

 

[Kpsnuts]

So a bit of a write up.

I've shimmed three difs and put in new oils: 50k, 300k, 100k.....wow the car handles in a much better way....really great. I used hobby king trackstar oil.

I used mugan and stock washers... I went with 2 either side of each planet gear....most say 2 and 1....but 2 and 2 worked well...not to tight.

When removing stock pinion grub screw and motor screws I used a soldering iron to heat through the red locktite....without it, it would have been a struggle. Soldering iron was effective. When I put the screws back in I used blue thread lock.

I got the mesh quite tight. I got the spur and pinion as tight as I could (no click) and secured into position. wierdly when I ran paper strip through...the paper didn't tear just crimped. I felt nervous leaving it that tight so eased off a little, til I got the faintest of clicks.

I've had around 5 runs with no issues.

So far so good....only problem is if I blip the throttle enough it backflips!!!

 

[Sully_]

Glad to hear you got your mesh set right @Kpsnuts. I'v been having an issue with that, but i think i got it right this time. Just beat the ever living poop out of my kraton , and didn't have any issues with the gearing or anything. I did order the hot racing motor mount though , and that should make adjusting the mesh WAY easier then this stock motor mount that seems to have already taken some damage.. Enjoy brother !

 

[slick2500]

So a bit of a write up.

I've shimmed three difs and put in new oils: 50k, 300k, 100k.....wow the car handles in a much better way....really great. I used hobby king trackstar oil.

I used mugan and stock washers... I went with 2 either side of each planet gear....most say 2 and 1....but 2 and 2 worked well...not to tight.

When removing stock pinion grub screw and motor screws I used a soldering iron to heat through the red locktite....without it, it would have been a struggle. Soldering iron was effective. When I put the screws back in I used blue thread lock.

I got the mesh quite tight. I got the spur and pinion as tight as I could (no click) and secured into position. wierdly when I ran paper strip through...the paper didn't tear just crimped. I felt nervous leaving it that tight so eased off a little, til I got the faintest of clicks.

I've had around 5 runs with no issues.

So far so good....only problem is if I blip the throttle enough it backflips!!!

To cut down on the back flips run thinner oil in your center diff, unless you want back flips.