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View Full Version : Proximity Sensors as Limit Switches ?



Lee Roberts
02-10-2009, 07:30 PM
Hey “yall”

I’m looking at limit switches for my new machine, has anyone used Proximity Sensor’s on their machine and is there a brand that would better for this job.

Also would the door sensors you find on house alarms be any good/reliable for this kind of thing?

Thanks,
Lee

Smiler
02-10-2009, 08:32 PM
Hey “yall”

I’m looking at limit switches for my new machine, has anyone used Proximity Sensor’s on their machine and is there a brand that would better for this job.

Also would the door sensors you find on house alarms be any good/reliable for this kind of thing?

Thanks,
Lee

Bad Juju.

prox sensors not accurate/repeatable enough (at a price you can afford) and get a speck of swarf, wood chips etc etc on the target and you lose any accuracy . Why you swimming against the stream man? Go with the flow, go mechanical, tried and true tech. Or optical if you like although they suffer similar problems to proximities.

You just trying to be different Mr. Lee?

Jeff.

tribbles
02-10-2009, 10:18 PM
I'm going magnetic with my limit switches. Home switches won't be repeatable (haven't decided what to do with them), but since limit switches are, for me, just in case of emergencies, it would be fine.

Plus I'm not cutting metals, so not too worried about swarf.

As a related aside, I do some electronics for a crop spraying company. My electronics controls a 4-wheel steering system, where it switches between 2-wheel and 4-wheel steering. When switching from 4 to 2, it can only do this when the front wheels are aligned. They use magnetic sensors for that with a thin plate bolted on to the steering rack. The magnetic sensor picks up the edge of the thin plate, and is accurate to about 2mm.

mike techserv
02-10-2009, 11:02 PM
Hi
we use inductive sensors from Wenglor or Baluff, seem to work fine.

mike

www.techservcnc.com (http://www.techservcnc.com)

irving2008
02-10-2009, 11:45 PM
Don't confuse limit switches, which are for emergencies, with home switches which need to be accurate and repeatable. Personaly I'd stick with mechanical switches since it is much easier to make these fail-safe compared to purely electronic ones.

Smiler
03-10-2009, 08:04 PM
Don't confuse limit switches, which are for emergencies, with home switches which need to be accurate and repeatable. Personaly I'd stick with mechanical switches since it is much easier to make these fail-safe compared to purely electronic ones.

Exactly my point. Put much more succinctly than I ever could.

And as Mach (which I use) can use them as both it IS important they are accurate, repeatable and reliable.

So there.