Limit Switch?

I am not quite sure what a limit switch is. What my team would like to do is put a push button on the "belly’ of the mini bot so that when it hits the pole it activates the motors. Does anyone know if this would be legal?



Short answer NO illegal; buttons are no part of the authorized list R92

Longer answer YES if you were to fabricate a button like thing say out of aluminum plate or like a PVC cap and this button like thing activated a limit switch then that would be legal. Assuming the fastners used to attach this “button” to the limmit switch were also listed in R92. Also if you could find a button like thing that is sold as a light switch. Sold at Home Depot or Lowes that also would be legal.

I would not be shocked if teams have done something like this

Anything sold as a limit switch is a limit switch. A button-type switch is not a limit switch, unless it is sold as a limit switch (which I’m 90% certain that your particular switch is not).

It may be possible to find or make a “locking” limit switch; that’s for you to find, as I’m not quite certain those exist commercially and your particular design may or may not be conducive to adding a latch of some form.

The typical switches supplied as limit switches in the KOP over the years worn are “push button” switches that just have a lever that trips them.

Here is an assortment of some switches that would be commonly marketed and sold as “limit switches”.

One of those could certainly be used as your “belly” switch, as is.

There are a number of ways to make it “latch” in the depressed position. A simple method is to have it activated by a lever that has just enough friction in it’s mounting hardware that the spring in the switch can’t over come.

In addition the GDC went back and removed the “that fits in a wall box” from the definition of “common household light switch”. So that opens up a bunch of switches that might be used on lamps.

Here is a link to the button we are looking at:



A limit switch is any switch that is used to detect an “end of travel” condition.

In other words, it’s a functional description, not a physical description. The GDC kind of messed up when they specified what part we can use, based on a functional description, rather than a physical description.

But what they appear to mean is what’s commonly known as a “microswitch”, which is a brand name that has become a generic term for a small rectangular snap action switch, usually with a lever that activates it.

Radio Shack sells a few of them. We used them on our minibot. The one with the roller on it works well for what you want to do.

While your linked switch could be used as a “limit switch” it is not marketed as such. I would unfortunately rule this as not meeting <R92> M. Sorry. The switches you received in the KOP can work better in this application.

Thank you all. It’s often faster to get good answers here than on the official Q&A.

The “limit switches” shown by Mr. V are sold as “lever switches” at our Radio Shack. Nevertheless, we will go with one of those.

2829 wishes you well at your competition.

The lever switches in the KoP are marketed as Limit Switches.
Maybe save you a trip to Radio Shack, since you already have them?