Kraton Pinion keeps moving

[Pablo1980]

Ive got a kraton exb with the max6 combo but my pinion gear keeps moving which ends up grinding against the motor mount. Im using the blue normal locktite thread lock but it seems to not hold very well.
I was just curious in what any of you guys use.

 

[LuigiMain]

Mine was doing this too. I just globbed a bunch of loctite on it and let it completely dry. At first I was just doing little dabs of loctite.

Completely cover that grub screw with loctite then torque the f out of it

 

[SrC]

This will prevent the pinion from sliding to the Motor mount and causing damage if the set screw lets loose.

CRUSH TUBE 5x7x5mm (2pcs) (ARA311026) | ARRMA - Designed Fast, Designed Tough (arrma-rc.com)

But Understand that set screws wear out and are consumable items. Have spares and use them only a few times if they are a problem. You can grind down the end of the set screw a bit to roughen the contact area better and may get better results if you don't have a new setscrew (grub screw) on hand.
Blue TL is just fine. Works for me. Red is an option , but I feel is overkill and what Arrma uses stock for factory assembly.

And, the most important thing is to let the TL set for 24 hours. IF you run it before the TL "CURES", you wasted your time with TL. TL wont work. It will even loosen faster than if you used no TL at all.
Done right, you don't need to bathe the Setscrew in TL. Just coat the threads fully. No blobbing! That can even seize up the Pinion to the motor's Armature's shaft next time you go to change out the pinion.
Use a torch or heat gun for TL removal always or risk stripping the set screw hex or hex driver.

 

[FlipSide]

Also, clean the threads of the set screw very well before you apply the thread locker.

My pinion was always coming loose as well and a nice cleaning of the threads with brake cleaner solved the issue.

 

[SrC]

^^^ THIS Clean TL parts always. Brake cleaner. A hard rule for sure.
I use Locktite 243 instead of 242.
It assembles well with dirty oily pre TL'ed screws no issue. Sometimes its hard to remove/ clean off old TL completely, especially RED TL FWIW.
Clean the pinion and setscrew and armature shaft.

 

[FatCatRC]

Those crush tubes seem like a really good idea. Woulda saved my pps mount. I use medium blue too even after cleaning well. It eliminates the chance of any oil messing it up. Especially with my aluminum diff cases.

 

[jkflow]

The secret to loctite is cleaning, next is cleaning and than some additional cleaning.
I use a tap tool to clean the pinion threads (M4) and a small steel brush (Dremel) on the grub screw followed with alcohol wipe down.
All issues will disappear. You also have to clean new items as they are coated in oil.

Next is the 24h cure, don't mess with it and leave it alone. This is NOT something to do on the field or an hour before the run.

 

[Grimbles]

To clean a set screw I like to get it red hot with a chefs blowtorch or windproof cigarette lighter, drop it in a capful of isopropyl then spin round in some kitchen roll. Squeaky clean after that and the loctite always sets lovely

 

[jkflow]

That will work but you are messing with the hardness if you overheat. Burning it off works though, just don't drop it

 

[Spoc85]

Ensure you’re lining the pinion grub screw up on the flat part of the motor shaft.
Throw another grub screw in for good measure if the pinion you are using has the option.

 

[SrC]

I do that sometimes. Some motors have double flats opposed 180 degrees for this purpose. If the pinion has two holes take advantage of this. Usually one motor shaft flat is shallower. I'll find a very short Grub screw or grind one shorter for the shallow flat side. This way the grub doesn't hit the Motor mount. Sucker ain't going no where.

 

[Pablo1980]

Some great advise and tips, im going to definitely get the crush tubes and going to give it a dam good clean before giving it another go. Thanks for all the help

 

[olds97_lss]

I use orange loctite on stubborn stuff. Not as permanent as red, but more so than blue. As mentioned, clean all oil off both the screw, threads, inside the pinion hole where it goes on the shaft and the shaft itself. Use a high quality allen (MIP or the like) to tighten and only use a grub screw once or twice. Even with a good allen, they strip, then your hosed... well, not hosed, but your life just got more complicated.

 

[Harriot10]

I use parts cleaner, orange TL, and MIP hex when installing my pinions. This has worked well for me. I also bought a bag of 100 grub screws, got plenty of extras.

 

[SrC]

Some great advise and tips, im going to definitely get the crush tubes and going to give it a dam good clean before giving it another go. Thanks for all the help

The crush tubes are just a failsafe backup. Prevents needless damage. Cant hurt. Cheap insurance for sure.
Installed properly, Pinions wont loosen to begin with. Honestly, I cant remember the last time I lost a pinion. For years and years.

 

[L3phturn]

Clean the grub screw, but clean the pinion threads too. Run the cleaned grub screw all the way in and out and clean both with brake cleaner. If you clean both thoroughly, use just enough blue thread lock, seat it properly on the motor shaft and let it cure a full 24 hrs you won’t have a problem.

Just a dab will do. Too much and it can’t cure properly.

 

[SrC]

TL attracts dirt and dust. And doesn't cure left exposed to air. TL reacts and cures when the threads are torqued and clamped firm, air forced out in between the threads. Only needed in the threads. That' how TL works. All the extra unnecessary TL is just a waste and will not dry. It gums up and makes a mess. Also too much makes the arm shaft seize to the pinion.

 

[Spoc85]

That will work but you are messing with the hardness if you overheat. Burning it off works though, just don't drop it

If he’s quenching that grub screw in that solution straight away the metal should strengthen.
If left to cool slowly it will weaken.

 

[Grimbles]

If he’s quenching that grub screw in that solution straight away the metal should strengthen.
If left to cool slowly it will weaken.

It goes straight in. I like the noise, bubbles and heady heady fumes

 

[M240i_bandit]

I seem to be having the same issue - luckily it didn't work its way down far enough to hide the grub so managed to get it off. This was after the first run so pretty sure everything was clean but I'll try some of the above - I'm sure I tightened it down as far as I could as well...

The crush tube seems to be OOS everywhere - is putting blue threadlock on the shaft as well to slightly fuse the shaft to the pinion an option?