Mounting limit switches

[MrWild]

I've been looking through the build pictures and don't see any pictures of how limit switches were mounted. I always like to see how those that have gone before me worked their solutions. I'm prone to copying elegant solutions.

Thanks

[NB70]

Here's how I did mine (with a couple of pictures)
[edit]CAUTION: these switches are mounted backwards (see comment below by Crevice Reamer!), they work but would be safer the other way around.[/edit]
Link: limit switches on JGRO
I mounted the limit switches on U shaped aluminium profile (stuck the microswitches on with epoxy) which then fits snugly over square aluminium tube. There is one for each axis and the tubes are screwed down at each end to the machine.

The switches can slide up and down the tube for adjustment, and are then kept in place with a set screw. I thought that some adjustment might be useful, to stop the machine running into hold-down clamps etc, but I haven't adjusted them much in practice.

The switches are tripped by HDPE ramps mounted on L shaped alumiunium angle left over from making the linear bearings.

There are two limit switches per axis, one of these on each axis doubles as a home switch.

[Crevice Reamer]

Nice setup! But those pictured switches are mounted backwards. You never want to risk bending the actuator arm AWAY from the switch. Force should always be applied TOWARD the switch.

CR.

[NB70]

Thanks for pointing it out CreviceReamer, you are quite right. When I put the switches on some of them were backwards: I considered changing them, but the ramps were pushing the switch down rather than back so I left them as they were.
But if something large got stuck to the ramp it could bend the actuator and fail to trip the switch: so they should be the way you say: I'll change the webpage to avoid confusion. Its an easy enough thing to fix, and there are lots of other modifications and repairs waiting for this machine when I clear the backlog of other jobs I have to do.

[MrWild]

Thats interesting. I'd have never thought about the arm being bent away. In fact, I had to change my Z design because one would have been backwards. I don't know though, just about anything can grab an unhoused micro switch and bend the arm whether it is the right way or wrong way. With the ramp in the picture giving force in the direction of the switch, it seems that the same accident that might bend the unhoused switch lever up, could happen in either direction.

My switches will be unhoused and open to dust and swarf like yours. Have you noticed any problems?