Wiring Diagram check

[Clive S]

On the PSU drawing you have the signs transposed for the +ve and -ve on the outputs.

I would not use the 36V PS as it is overkill on the size and you are just bringing more complications in to the system.

If you are using 24V why not get 24V fans?

Yes you do need to ground each stepper shield at the star point.

[eurikain]

Hello people ! Thanks for your great input :) I will modify the diagrams according to your advices. I do however have a few comments to make:

Hi G,

Dude, how did you guess ?

I have had quick look and don't see why you have to put relays into the home and limits circuit. It only makes more to go wrong and a relay introduces a time delay which could vary if your relay goes sticky.

I see you have relays for the homes which you don't want to be using. Wire them striaght to the Inputs on the BOB. Relay for the Limits wired in series is ok.

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 ?

This will put your home positions as a variable rather than fixed reference point.

Is that an issue or a personal opinion ? I am new to CNC, I honestly don't know what's best. So you're saying I should just have all switches as limits instead of separating homes / limits ? The only advantage I really see from this (with my current CNC knowledge) is that it would free up one pin on my board to introduce a touch probe later on in the build.

Also, when you hit a limit you need to have an override switch to be able to jog off the switch. The buzzer reminds you to reset the override.

You will have to set Mach3 to Auto reset Limts so you can reset Mach and reverse off the switch. Other wise you'll need a limit Override switch. Either works fine but overide switch is safer.

True ! I didn't think about it but it makes obvious sense :) Otherwise the machine wouldn't be able to keep moving. I like the safe option. I can add this override to the control box. As for the buzzer, I think I get the idea ;)

6Pst relay - you can get 'em, but at an ouch price. you could do the same job with DP relays, just use the latching one to control the others, and you can have as many as you need.

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

Have the E-stop relay turn off a Contactor for the higher power devices like VFD, WP and PSU. This will mean you can use lower rated E-stop relay with fewer contacts. Most Contactors also have an Aux relay contact for control Signals which you could use for the Enable relay. Contactor is much more suited to mains power than normal relay.

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 ?

On the PSU drawing you have the signs transposed for the +ve and -ve on the outputs.

Good catch, fixed it :)

I would not use the 36V PS as it is overkill on the size and you are just bringing more complications in to the system.

That's right. I'll just order a 24V and 5V PSU. $25 total on AliExpress vs. 100 Euros here in Belgium (which are PSU provided from China.....) loool

If you are using 24V why not get 24V fans?

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.

Yes you do need to ground each stepper shield at the star point.

How about the limit/home switches ?

[cropwell]

So you're saying I should just have all switches as limits instead of separating homes / limits ?

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

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 ?


How about the limit/home switches ?

Normally a BoB has 5 inputs, which map to pins 10 to 13 and 15 on the port. They seem to be ususally used as Homes, Limits, E-stop and touch probe, leaving one spare. If you absolutely need more, you can always use a second BoB, which I do. That second board is very simple, just opto isolated inputs and outputs. It's overkill though

1. You have to keep Homes and Limits as separate inputs. Mach3 treats them differently, Limits are more like pressing E-stop in function. Homing is a different process, Mach moves the axis towards the Home position until the switch trips, it then jogs back until the switch reverts to normal. It does this for Z, Y and X in that order. Z first so your cutting tool is clear and high before the gantry moves.

2. ST on a relay or switch refers to 'Single Throw' which means your contacts either make or break.
DT means you have a common (COM) contact which makes with a normally open (NO) contact when the relay is energised and when not it falls back to the normally
closed (NC) contact.
This change over can be Make-before-Break but is normally (on a relay) Make-after-Break.
6P means 6 poles which is 6 sets of contacts inside the switch or relay. SP is usual for single pole, DP for double pole, after that numbers are used.

3. Contactors are special construction relays, suited to switching higher voltages without arcing, normally used for 3phase and suited to long 'on' periods.

C'mon G.E., I didn't guess.

Happy Holiday

Rob

[JAZZCNC]

1. You have to keep Homes and Limits as separate inputs. Mach3 treats them differently, Limits are more like pressing E-stop in function. Homing is a different process, Mach moves the axis towards the Home position until the switch trips, it then jogs back until the switch reverts to normal.

Not strictly true Rob and I know you now this but for clarity sake for others I'm pointing this out.

Homes and Limits can share the same Input/switch provided they are wired directly to the inputs and not thru Relays also Mach is setup correctly.

When setup this way Mach changes how it homes.? It turns off limits while Homing and treats the switch has HOME switch. After Homing finish's it turns Limits back on and treats the Switch has Limits from that point on or until Homed again.
If you wire the Home switches to separate input then Mach will still monitor the Limits while Homing and trip if touched.
Also If you wire each home switch to individual input then you can have Mach simultanously home all Axis at the same time. (This does mean a slight change of Mach's Home script)

[eurikain]

Normally a BoB has 5 inputs

Mine does have five inputs (User Manual of 5Axis Breakout Board - Mach3).

1. You have to keep Homes and Limits as separate inputs. Mach3 treats them differently, Limits are more like pressing E-stop in function. Homing is a different process, Mach moves the axis towards the Home position until the switch trips, it then jogs back until the switch reverts to normal. It does this for Z, Y and X in that order. Z first so your cutting tool is clear and high before the gantry moves.

So I wire homes in series just like the limits, with an SPST relay ?

2. [...]

Great explanation :) I had guessed the S stood for "Simple", but "Double" didn't hit my mind ^^, as well as the other details. You are a good teacher :)

C'mon G.E., I didn't guess.

How stupid can I be looooool, duhhhhhh ! That's the "Rob" that put me on track x) You still have to send me an email ;) (and I still have to reply the one from Sunday :p). I thought you had fallen off some unsafe stairs, I'm glad to know you're alive ;) !

[JAZZCNC]

So I wire homes in series just like the limits, with an SPST relay ?

Your not paying attention enough "G" Read what's been wrote again and you'll see the answer to that question.!!

[cropwell]

G E

I had guessed the S stood for "Simple",

Guess again - it stands for SINGLE

I know what Bob you have, didn't I send you the manual in the first place ? I have two of those BoBs sitting in a drawer and two of the simple types, I made, with them. I plan to use 1 of each of them as replacements, but from then on any new controller will be ethernet.



I replied to your email on Sunday, I have forwarded a copy in case you didn't get it.


Jazz, I am actually trying to keep things as simple as possible and get OP shifting his gantry ASAP. I am just wondering if his original problem may have been the phase wiring on the stepper coils.

Jazz don't think I am having a pop at Yorkshiremen, I am not, every one of them I have met, were honest, down to earth, friendly and good humoured. In fact they both were. You can always tell a Yorkshireman, buuuuuut I am sure you know the rest.

Cheers

Rob

[eurikain]

G E
I had guessed the S stood for "Simple",
Guess again - it stands for SINGLE

Whoops ! Got me :)

I know what Bob you have, didn't I send you the manual in the first place ? I have two of those BoBs sitting in a drawer and two of the simple types, I made, with them.

Yes you did send me the manual :) See, the thing is that it's only today I realised that you were cropwell. I am getting more used to Rob :) Actually, where does that cropwell come from :D ? As in "crop well" ?

[JAZZCNC]

Jazz don't think I am having a pop at Yorkshiremen, I am not, every one of them I have met, were honest, down to earth, friendly and good humoured. In fact they both were. You can always tell a Yorkshireman, buuuuuut I am sure you know the rest.

Total Bull shit.!!! . . . . . Well know you've met 3 honest Yorkshire men.!! . . . . But I'm not really botherd Rob so carry on mate it's "watta of ducks arse" to me.. .

[eurikain]

Your not paying attention enough "G" Read what's been wrote again and you'll see the answer to that question.!!

Sorry, I wrote my reply before seeing what JAZZ wrote :) Plus, it's not that I'm not paying attention, I just want to make sure to understand properly. You're going to end up thinking I'm a bit mentally slow loooooooool.
So the answer is that there are two options:

1. homes on separate inputs
   +: possible to home all axes at the same time (while modifying the home script).
   -: you loose one input
2. homes on one input
   +: you save two inputs

No matter what, it's not necessary to use a relay for the homes.

See ? I'm a goooooooood student :) !