I just wanted to know, what is so bad about nylocks? And if we have them on out robot, should we replace them with locknuts?

I might’ve committed some atrocious crime against the sacred rules of the forum

But seriously, what are the pros and cons, and why are they “bad”?

Locknuts = keps
Woopsies, used to calling them that

Build with keps nuts, when the robot is all done, everything’s perfect, rebuild with nylocks.

Also, for some reason I heard some people use zipties instead of nuts/screws, is this just a joke Or…?

Wait, so basically, keps for building, nylocks for finalizing?

We build everything with nylocks… We know that if we build with keps nuts it’ll stay that way forever.

too true

Nylocks and locknuts are the same thing as far as I understand. I think you are referring to the difference between keps nuts and lock nuts. I think either one is fine; most of the time I just use keps nuts. If you tighten them well enough they pretty much never come out. As for lock nuts, I mainly use them for joints like on a lift and anything that shakes a lot.

I encourage my students to build using keps nuts, then once the design is relatively finalized use nylocks in the following situations. One, on joints that will pivot so as to stay attached in a situation where you want some play or two, in places that they do not want to come apart, particularly in places that would be hard to reach to tighten. However, any assembly that might require some disassembly in the pits should be keps nuts as they take less time and effort to remove in general.

As for the zipties, that is just a joke.

Never build final robot designs with keps nuts, period. You can tighten them all you want, but they will still get loose. And don’t state “Well my keps nuts don’t come loose”, however, there are scenarios where your robot might be under some stress and the parts will get loose. Do not take that risk. There are no real disadvantages to nylocks, they hold in tight, and only take about 1 more second to screw in compared to keps, which doesn’t matter that much. They also similar in weight. To answer your question, you are mistaken. Keps nuts are bad, even for prototyping sometimes, not nylocks.

I would say more like a good 5 seconds. And that’s not taking into account that you can’t screw them in without a wrench so you have to reach for the wrench if it’s not in your hand, so it might take even longer.

Zipties are actually useful to secure non-structural elements to the robot with a more flexible placement of them where holes in the metal wont line up properly to secure screws in them. (eg: attaching angled polycarbonate plates to a square frame)

With respect to the posts above, I think you can totally use Keps nuts for your final design. Just don’t only use the Allen Keys vex supplies, get some nice T-handled ones instead, that way you can easily apply more torque to the nuts so they will never loosen.
We never use Nylocks on any part that doesn’t need to pivot, nothing ever comes apart (Unless I am prototyping and thus not tightening things perfectly) and we save a surprising amount of weight.
You can find some nice tools for Vex here: RoboSource

Just remember to always make sure the washer on the Keps nut is flattened.

Just in my experience, 2 months ago, I would use nothing but locknuts. Now that I say how great they were, I use them a ton. The only time i’ve used kepnuts (starnuts) are from prototypes. Other than that, I would recommend locknuts for your final design.

I guess you’re right. I foolishly put keps nuts on my VEX demo robot and they eventually came loose after six or seven years. Mind you, I was turning them with a wrench at that point as I was disassembling the robot, but you’re right. Those bad keps nuts did come loose!

If you tighten keps nuts with a socket wrench, they don’t come off. In fact, I stripped a keps nut trying to take it off.

In my experience, neither are really necessary. Zipties, rubber bands, wires, pop rivets, and rope are quite sufficient to keep a robot together. Any problem can be solved by adding more of one of them. At least 3 keps nuts fall off every time I test my robot and it still functions perfectly. Other pieces that fall off with no significant consequences are collars, spacers, washers, standoffs, wheel legs, and even motors. I don’t even put most of them on the robot and they still appear spontaneously right when someone important is examining build quality.

(NOT SERIOUS) just in case you didn’t catch it :slight_smile:

On a more serious note, what are the actual names of the three types of Nuts i.e. metal with the spike disc, metal without the spike disc, and metal with rubber?

Nylock Nuts, Keps Nuts, and Hex Nuts.

But, which ones are they…

Nylocks are Locknuts(nuts with rubber), Kepnuts are starnuts(disc-shaped nuts), and Hexnuts are the ones without the disc shape

This is a promotional video for a type of locking bolt, but I think it would be interesting for people to see how bolts are testing for clamping pressure and the challenge of them coming loose.