About homing and switches...

**JW1977** · 05-09-2019

So, anybody got a good source for proximity sensors?
As i have understood, im in the market for the inductive kind. 4 mm sensing distance would do it and NPN/PNP should not matter with the Csmio IP-M. Emergency switch, some resistors and a main switch is also on the shopping list right now...

**john swift** · 05-09-2019

it depends on the budget your working to

if its a hobby machine then try amazon or ebay etc
buy 1 to check the quality then order the others you need

for a business machine you use to make a living
look at industrial suppliers like RS Components , Farnell or Rapidonline
for original proximity sensors not the cheep clones found else ware online

you will pay more but they will be to the published specification
example
https://uk.farnell.com/multicomp/mcp...imity%20sensor

John

PS
after looking at your location

https://se.farnell.com/

https://se.farnell.com/multicomp/mcp...weden%2Fsearch

**JAZZCNC** · 05-09-2019

Don't waste money buying the expensive switches Just buy the cheap Chinese switches off ebay.

I've fitted 100's and probably had about 3 in total that was faulty out of the bag. I've had about 5 fail in use over a 10yr+ period all on different machines.
The accuracy is more than good enough for any Router or DIY Milling machine.

The IP/M doesn't care which you use but I always fit NPN switches.

**JAZZCNC** · 05-09-2019

Originally Posted by JW1977

So, anybody got a good source for proximity sensors?
As i have understood, im in the market for the inductive kind. 4 mm sensing distance would do it and NPN/PNP should not matter with the Csmio IP-M. Emergency switch, some resistors and a main switch is also on the shopping list right now...

Why the resistors.? You don't need any for the IP/M

**routercnc** · 05-09-2019

Maybe you got confused with all the chatter of 10k internal resistors, pull-up resistors and so on. You paid good money for a quality controller and therefore the prox sensors just plug straight in !

I think I used resistors on the 12V front panel LEDs to run off 24V but that depends on how, or if , you want indicator lights for status and so on. For example they can also be mains powered indicator lights.

**JW1977** · 06-09-2019

Sorry guys, fuses, not resistors! Theres a lot on my mind right now...

However, havent got to it yet, collecting the final parts right now but, i read about one resistor in the driver manual.

Remark:
VCC is compatible with 5V or 24V;
R(3~5K) must be connected to control signal terminal.

If im not mistaken i think i read about it in in the Csmio manual also but they recommend a 2K resistor there!?

**Neale** · 09-09-2019

Couple of odd comments:

IP/M is very happy with direct connection of prox switches running on 24V. Works well.

IP/M drives the usual stepper drivers directly without needing any resistors. Use differential connection if your drivers support this - better noise resistance.

Unlike Jazz, I've not been too lucky with prox switches from eBay. I bought a box of ten. One was the wrong type (unbelievable! Two-wire, quite obviously not the same as the rest of the 3-wire switches), one was faulty straight from the box, and one failed very shortly after fitting. However, the rest have been working fine for a couple of years now, and the whole box probably cost less than one "professional" quality switch. That's the difference between home building and commercial - commercial machine could not stand that level of quality, but it suits my pocket!

**cropwell** · 09-09-2019

I too bought a box of 10 from China.

The machine I have from MD had end-on axial sensing and I crushed a sensor whilst jogging (the machine, not me!), In my naivety I ordered a replacement from MD and it cost £17.50 (ouch, ouch,ouch). When I crushed that one, I ordered 10 from China and converted the sensing to bypass.Some have orange sensor ends and a grey cable and some have blue ends and a black cable. I have 9 of them left. They are all NO and 4mm.

Cheers,

Rob-T

**Clive S** · 09-09-2019

I also have had about 30 from AliExpress with no duds with pnp and npn types.

**hanermo2** · 09-09-2019

My chicom mechanical switches are quite reliable, omron copies.

They are not too accurate, and the mechanical assys are terrible, in terms of machinist parts.
0.01-02 mm +/- in repeatability/accuracy is terrible.
For my cnc lathe, industrial quality.

But for routers, they are much more than good enough.

(My lathe is for sub-micron or 1 micron repeatability.)

Cheap 5$ optical limit switches provide about 2 microns accuracy, fairly easily.