PDA

View Full Version : Limit/home switches - how are you mounting 'em?



HankMcSpank
13-11-2011, 12:55 AM
So I want to add some home switches to my new little CNC, but I'm a little stumped how these things are physically (& robustly) affixed to the machine.

For example...

http://www.ebay.co.uk/itm/CNC-LASER-Machine-Limit-Switch-Sensor-C2-/150542770097?pt=LH_DefaultDomain_0&hash=item230d0c5fb1

are the two small holes...mounting holes, or are theyjust holding the switch together?!!!

I pulled some similar switches from some old dot matrix printers, but I'm stumped for a way of mounting them...gluing seems very cack....these things shouldn't ever be able to either move or fall off, but whenever I see a pic of a limit/home swithc it never jumps out at me "aha...so that's how you mount them!"

Personally, I immediately thought of a chassis mount barrel type switch...ie drill a small hole in my gantry upright, pop the switch in...it ain't going nowhere then....but alas ....not seeing any....must be missing the point (I normally do!)

Robin Hewitt
13-11-2011, 01:19 AM
They are mounting holes, usually around the 2 - 3mm mark.

The roller switch is usually activated by a ramp fixed to the moving component. Vast overshoot is okay. It's more a limit sensor than a position sensor.

A button microswitch is much better than a lever if you want position. Simply add a bolt to physically stop the slide before it crushes the switch. Theoretically you stop before you hit the bolt :naughty:

m_c
13-11-2011, 01:42 PM
As robin says, small screws through the holes work well.
There are various types of levers available on microswitches, it's just a case of picking a style that suits your needs.