I teach a high school robotics class and coach an after school club. We have 6 V-5 claw bots and a competition kit. I keep having the same hardware issue. Several times, almost on a weekly basis, students report that drive shaft on their drive trains keeping popping out of the motor’s seating resulting in the claw bot usually going in circles because only one wheel is turning. 9 times out 10, it’s typically the front right driveshaft on the clawbots.
I have double-checked the build plans for the claw bot several times and I’m rather confident that I have all the necessary shaft collars and spacers where they should be. Does anyone else have similar issues? I have trained my students to re-insert the drive shafts by now when it happens but it’s rather annoying. Have I overlooked something or is this a potential design flaw? Any solutions to keep the driveshafts in the motors during use would be helpful.
While its possible there may be some other issue with the way your students are mounting the shafts, a trick my students have been using is to drop in a gear insert whenever using a standard shaft since there is so little in the cartridge to hold the shaft.
Put a screw into a shaft collar, as you can tighten the shaft collar much more with a screw rather than the set screw. We never had any shafts pop out after the change
The problem is that the clawbot kits come with rubber shaft collars, rather than the metal ones that most competition teams use. If you replace the rubber ones with these, I am 99% sure your problem will be fixed.
We have rubber shaft collars, not the metal ones (didn’t know they existed. Here a picture of our setup  Grab one and put some stuff together.
To return to the OP’s issue, anytime you cantilever the wheels you run into those issues. Even putting in the inserts as firegnome suggested is not a cure. When cantilevering the wheels, there is nothing really holding the axles in the motors except friction. Several things can help. One, use omni wheels so that turning doesn’t cause a large lateral force on the wheels. Particularly on the outer wheels in a turn (left side wheels in a right turn), Two, and what we do with our competition robots, DON’T cantilever wheels. Build a box around the wheels so that the shaft collars can be placed in a way that resists the movement of the axles out of the motor