Wiring Diagram check

[JAZZCNC]

I use relays for the limit switches because I got inspired from JAZZ's OSCAR WINNING diagram (http://www.mycncuk.com/threads/9268-...ndle-VFD/page5). Thanks to Graem I understand that the limit switches in series are go through a relay because my BOB can't take 24V input so it isolates the BOB from that circuit. JAZZ, why would you not do the same for the home switches ?

Ok first not a good idea to use schematic unless you fully understand it and it takes your individual requirements into account. Your needs may different to what his where and you might not need relays..?

But the reason why not to use Relay for homes is because the delay in time for the relay to turn on translates into in-accuracy in repeatabilty of the Home position. This defeats the whole point of using them and makes home a variable position which is what Rob was saying.
Also because HOME signals are only used while homing they don't get has affected by noise like Limits do so can get away with directly using the 5V Input Logic.

Good to know :) I'm not sure what the difference is between PST relays and DP relays.

6PST means 6 contacts called poles which are Single throw type. So can only be NO or NC depending on which type contact you buy.

DP means Double throw so Can be Either NC or NO and each Set of contacts has 3 terminals. COM and NO or NC you choose which to wire to.
IE: 4PDT = 4 poles each with NO/NC position.

I just got inspired from your diagram, that's why I used relays on mine :) Or maybe DT relay it the other word for contactor ?

Nope Contactor is not DT it's like said above means Double throw. Contactor is basicly the Same has Relay but with heavy duty contacts which are better suited to higher voltages/currents. They also often have one or two sets of Aux contacts which can handle lower currents for using to signal to controllers etc. Again these contacts can be NO or NC.

Because I have looooooots of 12V fans at reach for free :) Would be waste not using them :) I can try to find some, but I think that might be overkill as I have more than enough fans I think (4 total). Well, I hear you already "you never have enough fans" lol.

2 x 12v wired in series with 24V supply is ok and what I do.

How about the limit/home switches ?

All Signal wire shields should go back to the Star Earth point.

Edit: Bugger didn't see Rob's reply could have saved my self load of typing.!!