My team has been having a little controversy between keps and nylock nuts so I wanted to get more opinions. We all know of the basic things like using nylock nuts at pivot points. But what do people use more often and why?
Nylock nuts weigh more, but have a better grip, so use them on parts that wobble a lot (flywheels, catapults).
When our team had our first tournament we used keps and we had to tighten them after every match. I would recommend nylock so you don’t have that problem.
I agree that nylock weigh more but not that much more, I don’t think it would be robot effecting.
What I tend to do is prototype with keps nuts, because they are easy to take on and off.
Then once you are ready to build it properly use nylock nuts.
The reason for this is that after about 3 - 4 uses, nylocks start to lose their locking ability, as the thread wears down the nylon at the end.
It will make prototyping go quicker and then make your final build a lot stronger. The annoying part is actually getting them on because you have to hold the nut while you tighten the screw. Many awkward hand positions have been made to get some nuts on.
We have used old nylocks before and have been suprised when they rattle off because they don’t lock as much anymore.
Keps Nuts All The Way!!! I have to say i have use nylocks for lift joint because they can have adjustable tension/ tightness. However, I have used Keps nuts for everything else on my previous Skyrise and NBN Robots and nothing has ever detached or fallen off. I know that nylocks are much better since they hardly ever loosen, but they take more effort and also they are heavier. My experience with Keps Nuts are fine, so i will probably keep using them. But, if there is a part of the robot that can never detach, then i will use nylocks for that part.
Keps for everything except for when things are pivoting on a bolt (like you said) or sometimes hard to reach bolts that are likely to come loose - like bearing flats on uprights.
Make every nut on the chassis a nylock… bad experiences
Make a flywheel with a slightly bent main shaft using keps nuts…bad experience
Make a slip gear piston with keps nuts and watch it fall apart while testing… bad experience…
Have done that too
+1
I nearly always work this way.
@NattyMan0007 SAAAAMMMMMMEEEE!!! But like actually Keps are just so easy to use. You only need the allen key to tighten them. This feature is especially useful when you can’t fit a wrench somewhere, and for me that happens way to often. Likely because of my poor planning skills 
I just made something in CAD, fits together with like 0.5mm tolerance. tried to build it. Oh wait…you need screws…
Keps nuts will come loose if there is a plastic component somewhere in the bolted assembly, like a nylon spacer or a flat bearing. For the Keps nut to lock properly, it must be able to torque until the lockwasher is fully compressed, and this requires all-metal to be bolted together tightly.
Vibration is a killer for the keps nuts. Take your robot on a nice car ride between events and see how many end up on the trunk floor. That is why nylocks are recommended.
There are also flatter nylocks on the market which are a bit less heavy.
Same for us.
WHY THE HECK IS THERE ANY CONTROVERSY, NYLON NUTS ARE WHY BETTER. The only reason they wouldn’t be is if your lazy.
Exactly what I do and recommend my teams to do. If the design hasn’t moved in the last two events, lock it down with they nylocks. But, always check them before an event just to make sure.
And as Team80 points out, there are slightly thinner ones you can use. Having a handful in your kit will make your life lots easier.
Is that a thing?