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eurikain
16-12-2015, 10:55 PM
Hello everyone,

I finally finished my wiring diagram ! Can anyone have a look at it and let me know what they think ? I used QEletrotech, which is great for custom parts but does not provide the option to set wire colors. It does have a few bugs on Mac OS X and crashes unexpectedly every 10 minutes, but other than that it's great !

Setup:


4 x AM882 drivers
4 x Nema23 4.2A 3.2mH from CNC4YOU
5 axis BOB
70V 10A DIY Linear Power Supply
36V 9.7A Switching Power Supply
VFD + 2.2kW water cooled spindle
Water pump
[ESS Smoothstepper to come into play in the next few months, currently focusing on having a machine that runs. Parallel port in enough for the first few weeks/months to learn and don't risk burning up a 225 Euro board.]

Before looking at the diagram, please read the following:

1. Notes:


The relay used with ENABLE is there to sensure that if something goes wrong with Mach3 or the BOB the steppers drivers don't keep streaming to the steppers. Most of you trust the software. I don't.
I am open to simplification ideas. Bear in mind that I am not an electronics engineer.

2. Questions I have:


I'm not sure it's possible to find 6PST relays (?).

Yes it is possible. It's cheaper to buy lower PST relays. You can get two 3PST relays and wire them
Can I use my 36VDC 9.7A power supply and convert it (using converters, if that exists ?) to 24V for the relays, 5V for the BOB and 12V for the fans ?

Yes, those converters exist, but it's easier, safer and cheaper to buy a 24V and 5V PSUs.

You can do it with DC-DC converters, but it might cost more than new power supplies. A potential problem with DC-DC converters is that they can become unstable is they are driving long wires and the load changes quickly.
Should I plug the water pump separately or make it's power source go through the control box in order to keep all connections and lines at one place ? (this is the option chosen in the current diagram)

Personal opinion: its power source should go through the control box mains relay/contactor. You want the E-STOP to turn it off, because water spilling everywhere while cutting because of some broken or not well attached pip would be a good reason to push it :GB_bonesrock:.
Is it necessary to put a fuse for the pump ? It's a cheap 6L/min chinese pump that plugs directly to the wall. I need to look for the power consumption but I doubt there are any inscriptions on it :/

Personal answer: it's up to everyone's choice. The pump will probably brake from its chinese quality instead of a power peek or short circuit.
Is it necessary - and if yes, why - to ground each stepper's shield ? Same question for the limit/home switches ?

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

The ground wire going to the stepper and limit switches is a "screen". You must not use it for a signal and must (in most cases) only connect it at one end of the wire. The idea of a screen is that any interference gets onto the screen (protecting the signal wires) which then dumps the energy into a common ground point. If you have multiple ground point then this energy can radiate out into the signals you are protecting. So for a noisy (electrically) CNC machine I will use screened cables for all external cables and some internal ones. The screen of all these will go to a single point where the earth connects to the control box.

Another solution, thought more expensive, is to use shielded cables which keep have a shield that contains interferences inside a Faraday Cage (made with a metallic braid).
How do I use the 24V input interface for spindle control ? How do I wire it to the VFD ?

Diagrams:


Main wiring diagram (drivers, BOB, and motors connections are detailed).
16845
Last updated Dec. 18, 2015.
PSU (reproduced from JAZZ's award winning video). Just double checking so I don't screw up my transformer a second time.
16838
Last updated Dec. 18, 2015.

Thank you for your help and patience :) !

PS: For those interested, here are the QElectrotech files:
16822

cropwell
17-12-2015, 12:48 AM
Hi G,

It looks slightly overcomplicated. I use KISS design techniques (Keep It Sodding Simple). It is a lesson I learnt when revisiting circuits I made some years ago. Mind you it could be dementia galloping in :witless:, or were they circuits I drew up yesterday ? :witless::witless:

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

Also, when you hit a limit you need to have an override switch to be able to jog off the switch.
16826

The buzzer reminds you to reset the override.

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.

Cheers,

Rob

There may be other problems, but I will leave those to the forum.

JAZZCNC
17-12-2015, 02:55 AM
It's late now and i'm too tired to look at it in detail but instantly 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. 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.

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.

Other than that then don't look too bad at first glance.

Clive S
17-12-2015, 08:42 AM
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
18-12-2015, 01:10 PM
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-Electronics-for-New-Machine-Chinese-Spindle-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
18-12-2015, 01:52 PM
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 :smile:

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
18-12-2015, 02:17 PM
I use relays for the limit switches because I got inspired from JAZZ's OSCAR WINNING diagram (http://www.mycncuk.com/threads/9268-Electronics-for-New-Machine-Chinese-Spindle-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.!!

JAZZCNC
18-12-2015, 02:30 PM
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
18-12-2015, 02:34 PM
Normally a BoB has 5 inputs
Mine does have five inputs (User Manual of 5Axis Breakout Board - Mach3 (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0ahUKEwjN1u6q8N7JAhXD1A4KHQg7BkkQFggvMAU&url=https%3A%2F%2Fwww.machsupport.com%2Fforum%2Fin dex.php%3Faction%3Ddlattach%3Btopic%3D29618.0%3Bat tach%3D40507&usg=AFQjCNH9X0BYQgc-jWmTqNv-W03KMGzhKw&sig2=JFiUP7HlDorfuQ69IWHl5w)).


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
18-12-2015, 03:05 PM
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
18-12-2015, 04:15 PM
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:beer:

Rob

eurikain
18-12-2015, 04:31 PM
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:

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

eurikain
18-12-2015, 04:42 PM
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
18-12-2015, 05:06 PM
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.. .:thumsup:

eurikain
18-12-2015, 05:32 PM
Alright, so I've updated the wiring diagram with the following changes:
- simplified connections to the 6PST relay
- 6PST relay to be replaced with a contractor driven by a relay. Just didn't want to break all the connections and rewire everything
- 24V and 5V PSUs
- 12V fans wired in series to the 24V PSU
- limit switches moved input pin
- home switches wired in series, with override switch and 5V idiot-proof buzzzzzzzzzer
- two input pins left, most likely one of which for a touch probe to come in the next few months
16846

I've also updated my original post with the answers to my questions and the new diagrams, so that anyone coming in the thread can follow along without reading through all messages.

Cnc many
19-12-2015, 10:38 AM
Hmm with all that built. In safety im surprised your using a single pole main switch on the ac input

Clive S
19-12-2015, 10:58 AM
Hmm with all that built. In safety im surprised your using a single pole main switch on the ac input
I don't see anything wrong with that in fact it will probably be plugged into a standard socket and a lot of these have two pole switches in now

JAZZCNC
19-12-2015, 11:34 AM
Hmm with all that built. In safety im surprised your using a single pole main switch on the ac input

Emm I don't see why people think this is high level of safety.? It's basic IMO and minimum a good machine should have.
Just because these machine are DIY built doesn't make them any less dangerous, they'll happily snap your arm or Rip a finger off just Like £150,000 Hass VMC will.
Like wise They'll Also quite happily turn your Hair into Afro or Burn your house down if you Mess with electrickery without knowing what your doing.!!

But I Don't think the schematic is going down to that level of detail and it's more to show a Switch and not the type. Rotary Door panel isolater switches break all lines so he'll probably use one of those.?

If not then at least it's got some switch and it won't be a problem.

eurikain
19-12-2015, 03:47 PM
Well, a switch is a switch :) Yes in the end it will be plugged in a wall socket, but I'll have a main switch for the control cabinet.

routercnc
19-12-2015, 11:27 PM
In your latest drawing I would not connect the mains supply of the VFD to the estop relay. It is better to have the estop connect to the run/stop lines of one of the VFD logic inputs so it is still powered when the spindle spools down. If you want you can add a delay timer which switches the mains supply to the VFD off after a few seconds (Jazz does this) but most people don't and it works fine.

eurikain
20-12-2015, 01:05 AM
Hello routercnc, thank you for the advice :)

To be honest, I received my spindle kit more than two months ago and have not yet powered the VFD and haven't looked at the manual much yet (I know there is a good stick thread on here that will help).

Though I know it's possible to control the VFD (run/stop, and speed) with the BOB, I am not sure how the controls actually work. Is the run/stop line of the VFD the equivalent of the ENABLE for the motors ?

cropwell
20-12-2015, 09:53 AM
For a Normally Closed limits circuit, you have to use a SPDT switch like this. In your diagram there is no power to the buzzer. You can use 12v or 5v buzzer, just connect the appropriate +ve voltage to the +ve of the buzzer.16852

eurikain
20-12-2015, 11:19 AM
I thought I understood your diagram but apparently not :/ So let's break it apart step by step:

The CN1 is the BOB's (CN == "Common 1" or "Input 1" ? + ground). You've also got a ground from each switch to the star point.

Now, how I understand its functioning:


In the initial state, current flows through SW1 to SW4 and then goes back to the BOB. The circuit is NC and Mach3 knows that limit switches are set to NC. Mach3 also is told that there is an override switch in Normally Open circuit.
Imagine SW1 triggers. The circuit opens, Mach3 notices and stops the machine.
Mach3 won't let you move the machine until you use the limits override. So, you press on SW4, which opens the switches circuit and closes the buzzer circuit. The buzzer starts beeeeeeeeeeeeeeping.
You move your gantry or whatever triggered, or home your machine to be safe and reset Mach3. This releases the triggered switch.
You move SW4 to its original position and the limits are now back into their original state. Mach3 notices and is now happy :)


I might be wrong on #4 and #5. I don't understand why you have a 12V buzzer. Doesn't the BOB send 5V through the limits circuit ? Therefore, having a 5V buzzer would be enough ? It seems to me like your diagram causes the BOB to take 12V in when you press the override switch. I'm not sure the BOB can take that much on the input pins (thought I know it can on the spindle control interface).

Now if you look at my diagram, it acts similarly to yours, I think :/ ? When a limit is triggers, it opens the circuit and you have to put the override switch in position 2, which closes the buzzer circuit. The buzzer is now powered with the BOB 5V (unless I'm wrong about the BOB sending 5V through those pins).

Pleas forgive my lack of understanding :)

Clive S
20-12-2015, 12:45 PM
It seems to me like your diagram causes the BOB to take 12V in when you press the override switch. I'm not sure the BOB can take that much on the input pins
I don't think you are understanding the relay contacts the 12 Volts -ve is connected to ground and the +ve is to the buzzer then though to the relay contact. Now when the override button is pressed the relay changes state and then grounds the buzzer to make it buz. In no way is it connected to the input pin on the bob

eurikain
20-12-2015, 01:19 PM
Oh wait I was confusing with the home switches ! I put the buzzer on the wrong circuit.. it should be on the limits circuit. So the CN1 is the relay right (in my case 24V) ? Let me update the diagram and post it again :)

eurikain
20-12-2015, 01:41 PM
How about now ? I moved the buzzer to the limits circuit. When you press the override switch, it does have power, right ?
16858

cropwell
20-12-2015, 01:53 PM
The CN1 is the BOB's (CN == "Common 1" or "Input 1" ? + ground).


You move your gantry or whatever triggered, or home your machine to be safe and reset Mach3. This releases the triggered switch.


I might be wrong on #4 and #5. I don't understand why you have a 12V buzzer. Doesn't the BOB send 5V through the limits circuit ? Therefore, having a 5V buzzer would be enough ? It seems to me like your diagram causes the BOB to take 12V in when you press the override switch. I'm not sure the BOB can take that much on the input pins (thought I know it can on the spindle control interface).

Now if you look at my diagram, it acts similarly to yours, I think :/ ? When a limit is triggers, it opens the circuit and you have to put the override switch in position 2, which closes the buzzer circuit. The buzzer is now powered with the BOB 5V (unless I'm wrong about the BOB sending 5V through those pins).


Hi,

My connector CN1 is just there to show the connection point to the BoB.

Do not try and power anything from the BoB input terminals. They may be at 5v due to internal pull-up resistors, but they will not supply enough current and you may damage the BoB. Likewise the output terminal should not feed any circuit with any power demand greater than a relay.

The buzzer can be any small DC buzzer, just feed the +ve side from an appropriate power supply, 5 or 12v depending on your buzzer. I just happened to have a couple in a drawer.

As Clive said my warning buzzer is a separate side of the switch. On my machine I separate ++ limits from -- limits so I use a 3pole double throw switch to override both inputs and also earth the buzzer.

Don't try and Home the machine when a limit is being overridden. You may be the wrong side of the Home switch and your machine will try to keep going in the wrong direction.

Before you connect Home and Limits to the BoB, verify they are correctly wired using a test meter. BoBs are fragile little buggers, so treat them well.

Why are you using a relay for Limits switching ? It only adds more to go wrong ! What would happen if your 24v power failed and you didn't notice.

Cheers,

Rob

Clive S
20-12-2015, 01:54 PM
How about now ? I moved the buzzer to the limits circuit. When you press the override switch, it does have power, right ?
16858Wrong first why don't you change the markings on the BOB so that they mean something correct ie you are showing that you are connecting the home switches to a Z limit etc.
You have now connected the buzzer in series with the relay coil!!

eurikain
20-12-2015, 02:16 PM
Here is the updated BOB input names. Sorry for the confusion I just copied the part setup from the manual. But they were actually not relevant.
16859
What's wrong with connecting the buzzer in series ? If you explain to me the role of the override switch and how it works then i'll probably be able to understand what is not right in my diagram :(
Here is the QElectrotech file, if that can be of any help :)
16860

cropwell
20-12-2015, 02:43 PM
What's wrong with connecting the buzzer in series ? If you explain to me the role of the override switch and how it works then i'll probably be able to understand what is not right in my diagram :(

16860

1. It is not a good practice to derive power feed in this way.
2. The buzzer will not pass enough current to pull in the relay.

Clive S
20-12-2015, 02:51 PM
Here is the updated BOB input names. Sorry for the confusion I just copied the part setup from the manual. But they were actually not relevant.
16859
What's wrong with connecting the buzzer in series ? If you explain to me the role of the override switch and how it works then i'll probably be able to understand what is not right in my diagram :(
Here is the QElectrotech file, if that can be of any help :)
16860The BOB input names are relevant especially when you are asking basic questions.
.

I believe you are using two 12V fans in series so that you can power them from a 24V supply now have a look at the drawing re the buzzer and the relay coil and see if you can work that out. (I am not trying to be difficult but you have to fully understand the reason) clue is you are halving the voltage with the fans.:friendly_wink:.
.
The purpose of the override switch is simply to provide a path to ground to energise the relay in the absence of a limit being tripped ie opened.

eurikain
20-12-2015, 04:27 PM
Alright, I get it now :) Wiring the buzzer in series drops the voltage in half, therefore both the relay and buzzer get 12V, which obviously isn't enough for the relay. So, I need to wire relay and buzzer in parallel and the SPDT switch allows opening the override line that bypasses all switches PLUS a parallel line where the buzzer is. Back to physics 101... ! :D Is this correct ?
16864

EDIT:
I still have to make the changes for the contractor and for the VFD stop.

Clive S
20-12-2015, 07:18 PM
Alright, I get it now :) Wiring the buzzer in series drops the voltage in half, therefore both the relay and buzzer get 12V, which obviously isn't enough for the relay. So, I need to wire relay and buzzer in parallel and the SPDT switch allows opening the override line that bypasses all switches PLUS a parallel line where the buzzer is. Back to physics 101... ! :D Is this correct ?
16864

EDIT:
I still have to make the changes for the contractor and for the VFD stop.

Ok You are getting there BUT if you look at the changeover switch how is the buzzer going to get its ground?
I feel it is better for you to work this out and then you will understand it.
Also if you will allow me to correct the name for the contactor instead of contractor (they are two different things in English.) I also wish I could speak your language as well:beer:

eurikain
20-12-2015, 07:23 PM
Whoops, forgot to pull that wire :) Sorry !!
I'm writing on a MacBook Air, OS X keeps correcting my words especially when it comes to electronics. Contactor gets automatically corrected to Contractor.. sorry :D Are you saying my English is bad ? Lord, didn't think it was that bad :'(
There you go :D
16865

Clive S
20-12-2015, 07:27 PM
Are you saying my English is bad ? Lord, didn't think it was that bad :'(
There you go :D
NO NO NO not in the slightest but I noticed from an earlier post you had done the same and just thought things had gone wrong in translation. I think your English is better than mine

eurikain
20-12-2015, 10:38 PM
Haha no worries :) Considering that I am not a native English speaker, I'll have to take that as a compliment :). Putting modesty aside, I have to admit that I lived in California a few years back and that's why I happen to have slightly better English than most French speakers you'll encounter :) I try my best to keep speaking, but especially writing and spelling correctly, otherwise you can loose your English in no time.

That aside, I still have a question =) Can someone look at the enable relay circuit I have in the diagram ? I had a discussion with Graeme and I am not sure whether the ENABLE is setup correctly. Should it be a NC or NO relay ? I'm asking because it is confused whether the ENABLE actually works backwards than what its name says. It seems to me that logically, the drivers should only be working when the "enable" gets powered up (5V) and disabled when it has no signal on the line (0V) ?

eurikain
16-01-2016, 07:22 PM
Last update of the diagrams:
1726217263

Note: this is a basic wiring diagram.

Potential changes / improvements:

Some people don't cut power directly from the VFD, they use a the start/stop pin of the VFD control interface and control it with a relay. This is safer for the spindle, it allows the VFD to slow down the spindle gradually without hurting it. if you really want to cut completely power from the VFD, some people (JAZZ apparently) also use a timer relay that delays for a few seconds the power cut to the VFD I'm not sure how to do it, I will look at it some time, and then modify the diagram in consequence.
Pull earth cable from the star point to the shield of stepper motors and limit switches.


QElectrotech files:
17264

Cheers.

JAZZCNC
16-01-2016, 08:16 PM
Statistically you'll use the E-STOP very few times over the life of your machine (unless you're goofy), so stopping all power going to the VFD won't hurt really.

No this is wrong you'll use the E-stop more than you realise. It's not always an emergency, sometimes you'll need to use it because you realise your going to hit a clamp or or Screw etc and don't have time to get to Control software to stop in controlled manner.

Who ever quoted me as using Timer relay with VFD is correct but only partly. Mostly I don't Kill power to the VFD I just send it Stop signal.



Pull earth cable from the star point to the shield of stepper motors and limit switches UNLESS you're using good shielded cable. In my case I'm using UTP ethernet shielded cable so no need for that. Plus I've got a VFD machine, so no real risk IMHO.

Again wrong. No matter the cable quality the shield should still go to Star ground. Ethernet cable can still be affected and Using a VFD makes it more important to have good grounding not less improtant.!

Clive S
16-01-2016, 08:20 PM
Statistically you'll use the E-STOP very few times over the life of your machine (unless you're goofy), so stopping all power going to the VFD won't hurt really. I think you will use the E-Stop more than you think. I for one would not kill the power to the VFD I would (but I don't) kill it with the stop control pin.

edit Dean beat me to it.

eurikain
16-01-2016, 09:18 PM
Sounds good, sorry for the misunderstanding. i'll earth everything. Can anyone provide a brief wiring diagram for how to do the trick please ?

JAZZCNC
16-01-2016, 09:28 PM
Can anyone provide a brief wiring diagram for how to do the trick please ?

What Trick.?

routercnc
17-01-2016, 12:12 AM
I think you mean the 'star ground'. This means all grounds from shields etc. all meet at one point, and this one point is then connected to the ground from your mains cable.

I'm not an electronics whizz but I think the idea is to avoid 'ground loops'.

Here is one of my older diagrams (a few changes since) - see the yellow cables which all join at a single point. This is then connected to the mains cable earth.
17266

Here is a picture of my control cabinet - ground is yellow and green. You can see that all of these cables meet up at a group of terminal blocks that are right next to each other (this is my star ground point). Because they are special earth terminal blocks they also connect to the metal DIN rail underneath which effectively joins them all together at that point. The middle terminal block then has a single wire which goes back out to the mains earth.

17265

Note that my VFD is completely separate (separate mains cable, shielding and earthing), but many people run everything off one socket.

eurikain
17-01-2016, 12:33 AM
Thanks routercnc for you explanations :) your cabinet looks great ! I've actually got the same DIN rail mounted terminal blocks / relays / yellow-green terminal blocks :)

My question was more about how you stop the spindle. On your diagram, I see the line that goes through the relay and connects to FWD and FVD control interface, but what powers it ? Is that wire getting 24V, or is it just a loop on the VFD itself ? Here is how I understand it: when you power up everything, the spindle can move forward because the loop DCM/FWD is closed. If the relay goes off, the circuit opens and the VFD stops the spindle because its DCM/FWD loop is broken. I am wrong again ?

Also, could you take another photo of your linear PSU please :) ? I like the way you did it but the resolution won't let me clearly see how you connected the capacitors together (it looks very neat).

JAZZCNC
17-01-2016, 10:21 AM
Here is how I understand it: when you power up everything, the spindle can move forward because the loop DCM/FWD is closed. If the relay goes off, the circuit opens and the VFD stops the spindle because its DCM/FWD loop is broken. I am wrong again ?

Correct works exactly like that. Very simple.

routercnc
17-01-2016, 04:40 PM
As Dean says just a simple circuit connecting 2 wires together.

Away from pc and workshop but there are photos of power supply on my build log 'router mk 3' or something like that
Capacitor cables are one cable with the sleeve cut out at the right intervals then soldered to the terminals

eurikain
18-01-2016, 12:02 AM
Correct works exactly like that. Very simple.
Very simple but not obvious for me haha ^^


As Dean says just a simple circuit connecting 2 wires together.

Away from pc and workshop but there are photos of power supply on my build log 'router mk 3' or something like that
Capacitor cables are one cable with the sleeve cut out at the right intervals then soldered to the terminals
Smarty pants ! That's a great way to do it ! Just need to get the hand at cutting the sleeve without cutting the wire haha :) Thanks for the advice ! It makes things much more simple. Will 2.5mm2 cable be enough ? My friend that works for the Belgian electricity company says 6amps per 1mm2, so 2.5mm2 goes 15A, good bet right ?

eurikain
30-01-2016, 12:55 AM
Correct works exactly like that. Very simple.

Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off. I know you're gonna end up thinking I'm dumb, but I promise I'm not that stupid haha :) Now, if using the DCM-RST loop, I guess it would have to be normally closed, so that when nothing's powered the spindle does not start, when the relay is on the RST line is off so the spindle can start/stop as I will, and then when power goes off (due to pressing the e-stop) the relay goes off and the RST line closes which stops the spindle.

JAZZCNC
30-01-2016, 12:01 PM
Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off.

Ok well same thing really just controling a different function and how you describe the relay etc is correct. BUT why wouldn't you want the software to Control ON/OFF if you have the abilty.? . . It makes life so much easier.!
You can walk away from the machine and Know it will stop the spindle when finished. It will Stop the Spindle between Tool changes and Start again when press Cycle start. Which is great when learning because it's common for people to push Cycle start after tool change then realise they haven't started the spindle.!!

cropwell
31-01-2016, 02:20 PM
Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off. I know you're gonna end up thinking I'm dumb, but I promise I'm not that stupid haha :) Now, if using the DCM-RST loop, I guess it would have to be normally closed, so that when nothing's powered the spindle does not start, when the relay is on the RST line is off so the spindle can start/stop as I will, and then when power goes off (due to pressing the e-stop) the relay goes off and the RST line closes which stops the spindle.

What you could do is use a two way switch with centre off. One way would switch the FOR-DCM directly and the other would put the FOR-DCM through a relay controlled by the BoB. That would give you three modes :- Fully ON,Totally OFF and Automatic. I do this for my Kress spindle and also my chip blower. I will probably do the same when I build the next machine with a VFD controlled spindle.

Cheers,

Rob

Clive S
31-01-2016, 04:36 PM
Rob I see the trouble with this is starting the machine code with the switch not in the correct position and then not getting to the Osh#t button fast enough

JAZZCNC
31-01-2016, 04:55 PM
What you could do is use a two way switch with centre off. One way would switch the FOR-DCM directly and the other would put the FOR-DCM through a relay controlled by the BoB. That would give you three modes :- Fully ON,Totally OFF and Automatic. I do this for my Kress spindle and also my chip blower. I will probably do the same when I build the next machine with a VFD controlled spindle.

Cheers,

Rob

Won't work Rob.! Well it will work for the Off bit but not for the option of controlling directly from VFD front panel or BOB. Problem is the VFD needs parameter setting to change from External control to Panel control.

cropwell
31-01-2016, 05:32 PM
Rob I see the trouble with this is starting the machine code with the switch not in the correct position and then not getting to the Osh#t button fast enough

I agree, but when you have done it a couple of times, you learn:chargrined:. I check the switch is in the correct position, but the 'always on' position is down, so you can hit it faster than the osht in my case. After having my finger bitten by the machine, it also helps my confidence to put it to 'off' whilst doing a tool change and restarting the code does not fire up the spindle, so I switch it to 'on' before continuing. My new Cam software puts out the M03 after a tool change though.

eurikain
31-01-2016, 06:56 PM
I hear you, but I don't see how the connecting the FOR-DCM loop through a relay would help the software control the VFD/spindle. For that I need to wire it to the BOB's VFD control interface, which I currently don't know how, as explained in my first post of this thread. I've given my BOB's model and manual already but I don't know how to use the BOB spindle control interface to control the vfd.. I would love someone to provide a simple wiring diagram with on one side the BOB's VFD control terminal and on the other side the VFD control interface and tell me how to wire the together.. I'm so sorry for looking like an idiot, but I prefer having someone explaining it clearly to me so I can understand it, because so far I haven't found such diagram on the forum.. :(

cropwell
01-02-2016, 12:10 AM
Won't work Rob.! Well it will work for the Off bit but not for the option of controlling directly from VFD front panel or BOB. Problem is the VFD needs parameter setting to change from External control to Panel control.

I was not intending to use panel control, but speed and direction control from the CSMIO-IP-S.

Looks like I will have to read up how the VFD works. My understanding was that DCM connected to FOR by a relay would cause the VFD to spin the motor according to the (0-10v) voltage applied to V1 and that opening the DCM, FOR connection would allow it to coast to a stop. All the setup articles I have seen are just how to connect R,S,T to single phase input and UVW to the motor, presumably then using the front panel to control ON/OFF and speed. I can't find any proper explanantion of the way RST (reset) works and what exactly it does.

Does anybody use braking resistors to pull the spindle to a halt ?

Cheers,

Rob

JAZZCNC
01-02-2016, 01:56 PM
I was not intending to use panel control, but speed and direction control from the CSMIO-IP-S.

Eurikain was talking about using the control panel but in anycase I don't see the point in what you suggest other than to disable ON?OFF. The Software allows you to manualy control spindle ON/OFF rather than G-code. The way you Suggest would work but is open to Error from forgetting to switch back and not turn spindle on before code starts and I don't care how fast you think you are there will be times when you do for get and can't reach it. Just like you can't reach O-shite button fast enough before it snaps cutter.!!
If you do want an actual Manual ON/OFF switch then better to use an Input and set up OEM trigger in Mach to turn Spindle ON/OFF.
If for Safety reasons then would only do this if it was tied to Reset so Control software can't start.


My understanding was that DCM connected to FOR by a relay would cause the VFD to spin the motor according to the (0-10v) voltage applied to V1 and that opening the DCM, FOR connection would allow it to coast to a stop. All the setup articles I have seen are just how to connect R,S,T to single phase input and UVW to the motor, presumably then using the front panel to control ON/OFF and speed. I can't find any proper explanantion of the way RST (reset) works and what exactly it does.

Your understanding is correct.
RST works just like Pressing STOP. Each of the VFD Inputs are programmable and can be set to do various controls and RST is set by default to same as pressing STOP button on control panel. When you Connect DCM to RST it Stops the VFD. Putting this thru E-stop contact will disable the VFD



I would love someone to provide a simple wiring diagram with on one side the BOB's VFD control terminal and on the other side the VFD control interface and tell me how to wire the together..

I'm not trawling back thru your posts to find out what BOB etc you have but if you post details again then I'll draw something for you.

eurikain
01-02-2016, 02:26 PM
I'm not trawling back thru your posts to find out what BOB etc you have but if you post details again then I'll draw something for you.

Jazz, you're the best :D

Here is my BOB's manual (I find it not too clear):
User Manual of 5Axis Breakout Board - Mach3 (https://www.google.be/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiyxtb40dbKAhWF_Q4KHR8uBX8QFggfMAA&url=https%3A%2F%2Fwww.machsupport.com%2Fforum%2Fin dex.php%3Faction%3Ddlattach%3Btopic%3D29618.0%3Bat tach%3D40507&usg=AFQjCNH9X0BYQgc-jWmTqNv-W03KMGzhKw&sig2=r3AlHppRzJTZ2JSBl94vVw)

Here is a picture of my VFD control interface (don't look at the cable, it's just a picture from google, not actually a picture from my VFD, but I checked that the terminals matched ^^):
https://www.buildyourcnc.com/images/inverterwire.JPG

My FVD manual (though mine has an English cover and some english mistakes):
http://www.jinlantrade.com/ebay/invertermanual.pdf

I think my BOB allows controlling on/off and speed as well for the vfd. If you can show me how to wire it in order to do that it would be awesome ! I don't know much about what Gcode can do beside positioning, but I guess it can embed speed control ? I'm also assuming that Mach3 is responsible for controlling on/off of the spindle when the g-code processing starts or stops (so it's not embedded in the g-code).

Thank you Jazz, you're awesome :) !!

cropwell
01-02-2016, 02:46 PM
Thanks for the info Dean. I am a bit cautious of turning power off to spindles after having the end of my right index finger chewed off by a facing cutter. I don't want to lose any more finger(s) or spend time in A&E being sewn back together. Given a choice between a snapped cutter or a finger, what would you choose ?

Eurikain beat me to the BoB info, but it is the type that has speed control and you can use the same pin as the B axis step for controlling an onboard relay to switch the spindle On/Off.
Cheers,
The Fat One

JAZZCNC
01-02-2016, 03:34 PM
It's easy see pic. Here we are using the Relay on the Spindle to Control ON/OFF. (Top 2 wires)
The bottom 2 wires are 0-10V for speed control.

You will need to change some parameters in the VFD. These tell the VFD it's being controlled from external source. (Won't be able to control from VFD front panel unless set back to 0)
PD001 = 1
PD002 = 1

Now just set Mach3 up according to manual regards Spindle speed and Relay control.

Edit: I loaded wrong Pic up first time, should have gone to V1 not A1. (Thanks for spotting Rob)

[ATTACH=CONFIG]17473

eurikain
02-02-2016, 12:15 AM
It's easy see pic. Here we are using the Relay on the Spindle to Control ON/OFF. (Top 2 wires)
The bottom 2 wires are 0-10V for speed control.

You will need to change some parameters in the VFD. These tell the VFD it's being controlled from external source. (Won't be able to control from VFD front panel unless set back to 0)
PD001 = 1
PD002 = 1

Now just set Mach3 up according to manual regards Spindle speed and Relay control.

Edit: I loaded wrong Pic up first time, should have gone to V1 not A1. (Thanks for spotting Rob)

[ATTACH=CONFIG]17473

Thank you SO much ! I will be connecting these four wires tomorrow and post pictures of the finished control cabinet :) ! Can't wait :D The machine's almost ready :D

I was also wondering what the 10-24V inputs of the BOB (between top 2 and bottom 2 pins you connected to the VFD) are used for ?

JAZZCNC
02-02-2016, 05:00 PM
I was also wondering what the 10-24V inputs of the BOB (between top 2 and bottom 2 pins you connected to the VFD) are used for ?

It's so you can power using an external source rather than USB and I suggest you do that. USB is unreliable and not to be trusted.

eurikain
02-02-2016, 07:05 PM
I have it powered by the USB port but it's connected to a 5A 5VDC PSU, don't worry :D

Also Jazz may I ask out of curiosity what tool you used to draw the connections ? :)

cropwell
02-02-2016, 08:46 PM
It's so you can power using an external source rather than USB and I suggest you do that. USB is unreliable and not to be trusted.

USB can't be trusted, but it isn't as bad as USA.:joker:

On a serious note, USB ports on a computer have a very low current sourcing capability.

eurikain
02-02-2016, 11:54 PM
USB can't be trusted, but it isn't as bad as USA.:joker:

Go to bed Rob, you're tired :D


On a serious note, USB ports on a computer have a very low current sourcing capability.

True, but you can still use the port if you power it with an external PSU :)

cropwell
03-02-2016, 01:35 AM
True, but you can still use the port if you power it with an external PSU :)

I think with that board, if you put an ohmeter on the +5v pin of the USB socket, it shows it connects to the +5v screw terminal connector, so the USB way of supplying power to the board is provided for those who want the quick and dirty solution.

Cheers,
Rob

A_Camera
13-05-2016, 12:09 PM
Why having a buzzer at all? When the limit switch is hit the motors will stop, so you'll notice the silence. When you push the Limit override you know you are pushing it...

Just curious about what is the point with the buzzer.

eurikain
13-05-2016, 02:18 PM
Because you don't "push" the limits override, you "switch" it. If it was a push button, you'd have to reach your keyboard or something that allows you to move the gantry off the triggered limit switch while you're pushing the override. However, a switch will stay in the same position, so you won't have the problem of reaching your keyboard, but instead you might have the problem of forgetting to switch it back to the "off" position, hence why a buzzer. It's not mandatory if you are very careful, but it's a plus for safety.

A_Camera
13-05-2016, 02:27 PM
A limit override should in my opinion be a push button, not a switch. Of course, I know that a switch stays on as long as you don't flip it but that is not a good solution the way I see it. If reaching to it is an issue than the position of the location is wrong. But again, this is just my opinion.

eurikain
13-05-2016, 04:54 PM
I see what you mean :) That's right, it's a matter of opinion.

nairepooc
08-08-2016, 01:16 PM
Hi Eurikain,

I have read through your post with great interest and it has answered many of my questions.
i was wondering if you have any photos of the control cabinet build yet?

eurikain
08-08-2016, 03:49 PM
Hello nairepooc,

Thank you so much for the compliment :) I do have pictures of the build but I won't be home until tomorrow evening, but once home I can post some pictures for you :)

All the best,
Eurikain.

eurikain
25-08-2016, 01:21 PM
Hello nairepooc,

First off, let me apologies for not posting earlier. I have been very busy these past few weeks, but I finally found some time to take those pictures you asked for. I hope these will be helpful to you. If you need more pictures, let me know. My camera turned on the flash for every picture, if you want I can try to take new ones without the flash, they might turn out a little brighter.

All the best, G.

19082
19083
19084
19085
19086
19087
19088
19089
19090
19091
19092

Tom J
03-01-2017, 05:56 PM
I think you mean the 'star ground'. This means all grounds from shields etc. all meet at one point, and this one point is then connected to the ground from your mains cable.

I'm not an electronics whizz but I think the idea is to avoid 'ground loops'.

Here is one of my older diagrams (a few changes since) - see the yellow cables which all join at a single point. This is then connected to the mains cable earth.
17266

Here is a picture of my control cabinet - ground is yellow and green. You can see that all of these cables meet up at a group of terminal blocks that are right next to each other (this is my star ground point). Because they are special earth terminal blocks they also connect to the metal DIN rail underneath which effectively joins them all together at that point. The middle terminal block then has a single wire which goes back out to the mains earth.

17265

Note that my VFD is completely separate (separate mains cable, shielding and earthing), but many people run everything off one socket.

What kind of transformer is used in your 68V PSU? Asking as you use MCB is tybe D which would be ok for torus trafo.

Clive S
03-01-2017, 06:08 PM
What kind of transformer is used in your 68V PSU? Asking as you use MCB is tybe D which would be ok for torus trafo.

It will be a toroidal transformer 25-25v AC in series or 50-50 in parallel MCB D type

routercnc
03-01-2017, 07:37 PM
Hi Tom,

I used 750VA, 2x24v in series (close Clive, I know some use 2x25v but I think it tipped the voltage a bit high once rectified and smoothed etc. ? Can't remember. I get 72V unloaded so OK with that.)

Toroid from Airlink transformers:
http://www.airlinktransformers.com/

Read post #42 onwards for the Toroid/PSU development, and read post #70 for the 'final' wiring diagram. . .
http://www.mycncuk.com/threads/6988-routercnc_MK3/page5

Note that I went with the 10A Type D MCB in the end as the 6A tripped out on startup due to the inrush current (no soft start). It's been running fine since.

Thanks

Tom J
03-01-2017, 08:03 PM
Hi Tom,

I used 750VA, 2x24v in series (close Clive, I know some use 2x25v but I think it tipped the voltage a bit high once rectified and smoothed etc. ? Can't remember. I get 72V unloaded so OK with that.)

Note that I went with the 10A Type D MCB in the end as the 6A tripped out on startup due to the inrush current (no soft start). It's been running fine since.

Thanks

I have both 720VA 2x30V 2x12A and 420VA 2x30 2x7A in two different application. All secondary winding have to be in phase (start 1st coil & start 2nd coil as one cable and end 1st coil with end 2nd as one cable)
I tried 4A type D MCB and was tripping out from time to time on 720VA - did not try bigger MCB, will do try on smaller 420VA.
I might get away from using soft start

Tom J
04-02-2017, 07:44 PM
I have both 720VA 2x30V 2x12A and 420VA 2x30 2x7A in two different application. All secondary winding have to be in phase (start 1st coil & start 2nd coil as one cable and end 1st coil with end 2nd as one cable)
I tried 4A type D MCB and was tripping out from time to time on 720VA - did not try bigger MCB, will do try on smaller 420VA.
I might get away from using soft start

Got recently 2x45V AC 500VA nad was tripping 4A type D MCB as well, will update with 6A or 10A type D when they arrive.

Nr1madman
05-12-2017, 07:54 AM
Thanks for an exelent thread!
Will be stealing much from the latest schematic for my own build.
Just have a question :)

Why is the enable signal wired in a relay that's controlled by the master relay?
Why not just use the master relay and skip one relay?

Thanks
Robert

Skickat från min SM-G955F via Tapatalk

john swift
05-12-2017, 02:51 PM
looking at diagram in post 42 I have noticed two issues-

I would expect wiring in series a 12V fan & 12V pump across a 24V supply will damage the fan !
( pump will look like a short circuit so most of the 24V will be across the fan )

connecting a diode (FR607 ?) across each stepper driver supply fuse
will provide a path for the back EMF from the stepper motor
when a fuse blows

see revised diagram
23315

John

Nr1madman
08-12-2017, 02:11 PM
looking at diagram in post 42 I have noticed two issues-

I would expect wiring in series a 12V fan & 12V pump across a 24V supply will damage the fan !
( pump will look like a short circuit so most of the 24V will be across the fan )

connecting a diode (FR607 ?) across each stepper driver supply fuse
will provide a path for the back EMF from the stepper motor
when a fuse blows

see revised diagram
23315

JohnAbout the diodes across the fuses for stepper drivers..
How big of a problem is it if you don't use a diod?

In my mind it's more probable that the fuse will break during acceleration instead of deceleration?

I might be wrong? :)

Skickat från min SM-G955F via Tapatalk

cropwell
08-12-2017, 06:22 PM
I think that the driver output stages have back emf protection, as the first vulnerable components are the switching transistors. I have been unable to find a circuit for that driver, but they are all much of a muchness. A diode across the fuses is belt and braces.

I totally agree about the pump and fan.

Neale
08-12-2017, 08:31 PM
Why bother with the diode at all? Just another complication. The driver itself has overcurrent protection so if there is a wiring or motor fault, the driver should turn off and raise a fault signal. So all the fuse is doing is protecting the wiring if there is an internal fault in the driver. The fuse does not protect the driver - the fuse blows after the driver has already failed. So, thinking this through, the fuse will blow because of a driver fault, so you don't need to protect this driver any more, and the blown fuse will isolate that driver from the PSU and other drivers as well - if the PSU fuse hasn't blown as well.

I just have a single fuse in the PSU feeding all the drivers, rated at the nominal capacity of the PSU. Anyway, will the back EMF on a fault be any higher than the back EMF in normal use while decelerating?

Nr1madman
08-12-2017, 08:40 PM
Doesn't feel like it could be higher as the motors generate the back current and not the driver..


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