Mechanical vs NPN Prox switch and power supply?

[Livnpaintball]

I’m stupid!, so now we got that out of the way I’m still working on getting my mill running. Still on the wiring portion. Now to the question, limit vs home switches, what’s the difference? Should you have home switches for home and then limit on the other end of the axis? Or can I get by with using just home switches?

I currently have some mechanical limit switches and some NPN prox switches ready to be used BUT I read that you need to use a different power supply for the NPN prox switches because it will be unstable if you use the Acorn power supply.? I also saw somewhere that mechanical switches suck with the Acorn.?

I’m drowning with this project, please throw me a life preserver!!

[Nigelo]

There is absolutely nothing wrong with using mechanical switches provided they are NC and of good quality with excellent repeatability. My Wabeco Mill uses Euchner N01K550-M Homing switches as an OEM fitment and they are accurate well within their stated 20 microns (approx 0.0008") and highly repeatable. Just make sure yours are NC for safety rather than NO

Whilst you can use limit switches at the far end of Axis travel, they are not essential as you can and should set software limits for each Axis within CNC12 anyway. Installing limit switches should therefore be looked at as a belt and braces (suspenders) solution but they will require one or more additional inputs

Hope this helps

[martyscncgarage]

I’m stupid!, so now we got that out of the way I’m still working on getting my mill running. Still on the wiring portion. Now to the question, limit vs home switches, what’s the difference? Should you have home switches for home and then limit on the other end of the axis? Or can I get by with using just home switches?

I currently have some mechanical limit switches and some NPN prox switches ready to be used BUT I read that you need to use a different power supply for the NPN prox switches because it will be unstable if you use the Acorn power supply.? I also saw somewhere that mechanical switches suck with the Acorn.?

I’m drowning with this project, please throw me a life preserver!!

Would be good if you had ONE build thread. That way we can scan back through messages and read about physical size of the machine, what drives and motors you are using.
There cheap and very good mechanical limit switches as Nigelo said. Proximity shouldn't draw all that much. That said you can easily upgrade the Acorn power supply to a din mounted Mean Well power supply with over twice the current capacity. Pretty inexpensive from Amazon:
MEAN WELL MDR-60-24 DIN-Rail Power Supply 24V 2.5 Amp 60W
by Amazon.com
Learn more:

You can series your NPN NC switches to ONE input and assign it homeall and then simply use soft limits and the control will take care of it from there.

[ShawnM]

Here comes the life preserver, be sure and catch it.

If you have normally closed NPN switches I'd use those first unless you have high dollar, high quality mechanical switches. Your NPN switches are probably 6-30 volts, yes? I have 3 NPN switches wired in series running off the same Acorn 24 volt power supply with no issues. I have all 3 NPN switches setup as "HomeAll" wired to input 1 and have my soft limits set for the max travel. Works flawlessly with no issues. Very simple and it saves an input for something else. If you want limit switches for the max travel there's no problem with that either. It's just more wiring and more inputs used up.

Hope this helps and try to keep your head above water.

[Livnpaintball]

Thanks guys for the life line, I will ditch the mechanical switches and us the NPN for home! That Mean Well ps is a nice little package. I may use those instead of my current set up.

[S1Loki]

My entire set-up is using Meanwell MDR and SDR power supplies.