KEPS Nuts or Nylock nuts?

Which is best for which part of the robot?

I find Nylocks good for any moving part of your robot, but KEPS for plastics because the teeth grip the plastic and really create a firm hold.

It depends, Nylocks are a little bulkier and difficult to take on or off, but will practically never come loose. Keps are good for areas where space is limited or for quick prototyping.

One application I would highly recommend Nylocks for is anything that might vibrate, such as the parts holding the flywheel together, as Keps nuts will vibrate loose. In general, it’s good to use Nylock nuts for a low maintenance robot, but another thing to keep in mind is that they do weigh a good bit more than Keps nuts which does add up, so I would not use them unnecessarily.

I’ve never found it common practice to use Keps Nuts over Nylock ever on a competition robot…

maybe I’m missing something.

I hate KEPS nuts. They never stay tight. I don’t understand why they have the integrated washer, because they simply don’t work.

We use standard hex nuts with lock washers. They don’t come loose and tey aren’t as annoying to take on and off as Nylocks.

Is that legal now? It didn’t used to be but some rules have changed since 2012.
https://vexforum.com/t/answered-lock-washers/20495/1&highlight=lock+washers

We find that, for the most part, nylocks are superior to keps nuts in most situations. The washer on the keps nut simply doesn’t work. One thing to note with nylocks, if the screw doesn’t penetrate the rubber part of the nylock IT WONT WORK. This makes using quarter inch screws for quick assembly not an option.

Nylocks are for joints.

Keps nuts are for static constructions.

If you tighten down a keps nut hard it wont come loose.
Additionally the washer isn’t supposed to keep the keps nut tight, its designed so that it’s the opposite of a nylock nut. When you only spin the screw, the nut will tighten unlike on a nylock nut where the nut will just spin and you have to use a wrench. That’s what the washer on a keps nut is for.

Our teams use a lot of Keps nuts, and very rarely use Nylock nuts for anything. Of the two times that I have seen Nylock nuts used by any of our teams, one was when we almost ran out of Keps nuts. Basically, ignoring the scarcity of Keps nuts scenario, use Nylock nuts if it’s a) definitely not being rebuilt for a while, and b) the screw and/or nut might rotate.

Prototype quickly with Keps and permanently build with Nylocks is our general rule.

Unless you can easily access the nut location try and use a Nylock. Vibrations like a nice car ride to an event an hour away will shake the robot a bit and you will have a few loose nuts.

So if it is easily available for a quick tightening, you can use Keps but be warned it will come loose eventually.

Unless something needs to have space to move, like a simple joint, I use keps nuts. With the correct allen wrench I can get them tight enough that they will not come off for months. However, for a general rule, for competition, nylock on bearings and joints, keps for structure( allows you to make small adjustments in angles easily), and nylock for triangle shaped trusses (keeps the tension correct over a longer time to keep structures intact). By a state competition or going to worlds, the robot should be +85% nylock.

Honestly I never realized it was potentially illegal. I hope we weren’t inadvertently breaking any rules in the past. This year I do see it says:

So I would think it is safe to assume lock washers are legal this year?

I have 4 years of loose keps nuts that say otherwise :smiley:

Unless perhaps you buy titanium screws and nuts so you can actually tighten them sufficiently without just stripping the heads out.

Obviously I’m being sarcastic, but we truly do have a terrible time with keps staying tight, no matter how tight they are originally.

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Well, that sounds like it is now legal, but it’s not my decision.

For what it’s worth, I use Keps for prototyping and Nylock for final designs (space permitting).

Maybe it’s time to invest in some nicer drivers? It is very rare that a properly tightened keps will come loose. I have a bad habit of not using a wrench so mine come loose more frequently, but I tighten everything the morning of a competition. If you don’t want to buy higher quality drivers you can tighten first with an Allen key and then use a wrench to crank the nut farther and it will be pretty tight.

Nylocks are great, until you have to remove a stripped screw…

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I use a socket wrench on the keps nuts I need to stay tight, and they NEVER loosen. Granted, we’re a second year team who hasn’t kept anything together for more than 2 months, but they seem pretty tight.

Agreed. That’s why we have gone to the deep socket head type screws where ever possible. In some spots where space is a premium we have to use the button head type, but we avoid it.

Though Mr. Murphy insists that the least accessible screw head will be the one most likely to strip :eek:

Wouldn’t he say that all the screws will strip?