Hey guys; I recently purchased the Cen colossus 1/7 scale truck, and this morning I took a few minutes to enjoy running it before work...well, after 10 minutes of running it, the set screw on the motor pinion gear came loose; and this is not the first time; it happened last week and I put blue thread locker on the set screw, but it has indeed come loose again! Should I put red locker o the set screw, or not? Our local hobby shop owner said that they don't even stock red because of not being able to free up the screw for maintenance after it is applied; what do you guys think I should do?

I would avoid using red unless you never intend to change pinion gears again. I would make sure the grub screw and pinion are clean, then apply blue thread lock and tighten. Then let it sit overnight to set. If you're just assembling and then taking it out right away, that's your issue. The loctite needs time to set. If you use red, the only way to get red to loosen up is to apply a lot of heat and you would risk damaging things.

A trick that I've been using that has worked exceptionally well for me is, prior to installation, to put blue thread lock on screws and let them sit overnight. The thread lock sets up and then when installing the screws the next day they feel slightly tighter going in. By only allowing the thread lock to coat one surface the locking effect isn't as strong but feels just right. I've used this trick on my AE chassis screws and have yet to have one come loose. I have heard of guys using red to lock the screws on their spool drive cups, but I never use red myself as it seems like overkill and as previously mentioned above is a royal pain to get off.

Thanks guys fr both of your responses; the thread locker I was using was supposed to be a quick drying locker; I did rush out and run it afterwards; I will try applying the locker and letting it sit as mentioned; thanks again!

i never use red loctite : it's really hard to get off the screws with red loctite ! my CEN for exemple has some blue loctite and it never failed. a night of "drying" is indeed needed !

Pinions usually don't come loose even without any Loctite so I would consider getting a new, quality pinion. As others have said, don't use red on anything you might ever want to loosen again.

i never managed to run longer than 10 sec without loctite on my motor pinion !!

The motor pinion o this Cen appears to be really good quality; plus, I did program the punch to level 7, so I am sure that the constant torque from wheelie's is tough on the drive train; considering this thing is heavy mass to move so quickly.

I also use the method above, of putting thread locker on to dry for a day prior to installation, on my pinion set screws. Again, never had one come loose. I'm running touring cars so the torque many not be comparable though.

A trick with set screws that lock against a flat on a shaft is to grind down the tip of the set screw to make it flatter. A lot of them have a tapered tip and it puts all the pressure on a small section of the center of the shaft and it allows it to work back and forth over time.

Thats a really good shot man! That is screen saver material.

thanks, it's a screenshot of a video. as this thread was about a CEN, posted it ! lol

Man you are crazy!!! That thing looks like it is 35 ft in the air! Did you break anything on that jump? Or better yet, to keep the thread in the context, did your blue thread locker hold up?

haha thanks man, didn't you see my CEN videos ? of course i had some crash, there a gringy video only about crashes ! no thread lock failure though !!

Yeah I saw your vid's; your definitely push these things to there limit for durability; keep up the good work!