Printable View
Ahhhh. Right. Thanks Clive.
That's better.
So lets say 3 amps from the PSU controlling stepper motors and i think i read 9 max from a VFD.. ?
So does that mean I could potentially run it all off one plug then with a 13a fuse?
Sorry for the dumbness on my behalf. I had to remind myself how a ground / fuse works earlier.
Getting there...
I think you said that you read every word 5 times. It has been said several times that you can power your system from one plug. You really should take the advise from the good people on here:beer: all these questions have been asked lots of times.Quote:
Originally Posted by mturneruk
The absolute correct way to do it is to use a relay to tell the software to say stop to the VFD, meanwhile a timed relay cuts the power after a second or so by which time the stop signal has reached the VFD...Quote:
Originally Posted by mturneruk
Thanks !
Really getting somewhere now.
So it's decided that I need one power input into my enclosure and split it. Not listening to the bloke that told me I had to run two plugs any more.
So one side of the internal mains split will go to an EMI filter and then to the VFD.
The other side of the split will go directly to the 48V PSU.
One single all in one 10Amp chassis connector / fuse / power switch.
Easy. Job done.
Apart from Emergency stop.
So can anyone confirm why I can't just use an inline mains e-stop button. How does a relay do the job better ?
Thanks massively for your help.
Martin
Clive.
Just been trying to work out who the good people are!
I've had so much conflicting advice, it's hard to tell what's real and what isn't.
Found the answer to that now.
NJ. Thanks.
Neale. Thanks. I use those Network plugs to around my house. Will look out for the drop out. Wonder if the EMI filter might stop that.
Thanks
Martin
Ok I've done you a quick Diagram but If your not going to listen your just wasting peoples time and I'm time short as it is.! So either take heed or don't waste my time asking questions your going to ignore just because it's not what you want to hear.!!Quote:
Originally Posted by mturneruk
The reason that isn't safe is because the minute you release the E-stop the machine is live again and in some circumstances could just takeoff if the Control software is still out putting pulses.
Also your dealing with Mains voltage levels at the E-stop switch which isn't ideal. Much better to handle control of high voltage with low voltage switch gear.
Proper Safe system should shut down Critical power in safe manner and inform any relavant parties, ie Control software. Then when fault is cleared power should only be restored in a controlled manner IE: With Reset Button that won't allow Reset unless fault is cleared.
The system I've drawn you is the simpliest but Safest E-stop there is without getting daft. It may look complicated but it isn't. It uses only one 4 pole Normally Open relay for the Safety side and one Momentery NO Switch.
On top of this I've included another relay to give you a better Limit switch system to protect against noise. This uses 24V running thru the switches to control turn on Relay that if tripped or wire breaks then cuts Signal from BOB and informs the Control system Limit trip as occured.
This means the 5V Signal wires form the BOB can be kept very short so much better protected from noise than if running all the way around the limit wires acting like an arial. 24V also keeps the contacts of the switches cleaner so less switch bounce.
I've drawn the Fan running on 48V which isn't ideal because they would be turned off with E-stop but thought you already had them so if you haven't got them already then buy 24Vdc fans and run directly from the 24vdc supply.
All this lot, inc VFD will happily run of a 13amp fuse on a single socket.
Now here's my Disclaimer. Use this diagram at your own risk I accept no liabilty if any errors and warn you it's a minimum of safety.
Regards the Fans then you will get dust even with an extractor so fit a filter. Ideally you want 2 fans with filters blowing Air into the case and then vent hot air out. This provides positive pressure and keeps dust out while rapidly removing heat.
Your lack of space makes this even more important so skip this step and you'll shorten life of anything in there.!
Attachment 16642
Amazing. Jazz. Digesting. Thanks for your effort!
Listening. Think I might owe you a few beers.
Only problem is I have a feeling I might have to ask you some more questions.
Martin
For the limit switch circuit Jazz proposes, you should add a diode across the relay coil to suppress the inductive spike, which would otherwise reduce the lifetime of the switches. If you're using them just as limits, not home switches, then that's not the end of the world. Either way I'd be more keen on using a transistor in place of that relay, since it also (for all intense and purposes) removes the small delay caused by the relay contacts moving. Again, not such a big deal for limit switches but it would reduce the accuracy if these are used for homing.
I wouldn't bother fusing the fan - do you really care if it blows up, it's only a fan...
Don't have a problem with asking.! . . . . Don't have a problem with not understanding.! . . . . . . Do have a problem with not listening.!!Quote:
Originally Posted by mturneruk
There are many many wise people on here and NONE will deliberately send you wrong.! . . Some tell it better than others. Some say the same thing but go round the houses. Some say it in ways only Nasa trained alians understand.!!! . . . But all say it with helping in mind and good intentions. So when more than a few say the same thing, even if said in differant ways then ignoring what's said is sure fire way to piss folks off and make them look the other way when you really do need there help and only they know the answer.!
Speaking of NASA trained Alians and then one appears. . LolQuote:
Originally Posted by Jonathan
I was trying to keep it simple Jon and most Relays come with Diode these days so didn't want to complicate things, esp with Transistors.
Was for Limits only has you know I wouldn't suggest running thru Relay for Homes.
Wonder how many houses and garages have burned down because it's Only a Fan.!!Quote:
Originally Posted by Jonathan
Ok. So I slept on it.
Your right Jazz. I didn't want to hear it. Sorry.
Having a built a machine before and managed to all the wiring myself, which ran fine for 3 years I was not expecting to run into these complications / expenses.
Also I have been fed some crap information from another source, which I thought I trusted. Not any more.
I massively respect the fact that you went to the trouble of doing me a really good wiring diagram, and everyone on here has spent so much time answering my newb questions. Thanks chaps.
So I am fully listening now, and I am signed up to your wiring diagram.
Questions.
1. On my previous machine I used a latching emergency stop. Could I use that instead of having the reset button as well?
That is once you press it in, it stays in until you twist the emergency stop to release. Not trying to cut corners, just wondering if that does the same job ?
2. Is there any reason why I cant use panel mount fuse holders e.g. http://uk.rs-online.com/web/p/panel-...lders/0563784/
3. Does this relay look like it will do the job ?. This is an 8A.
4. I was planning to use 5 limit switches, 3 of which were going to double up as homing switches. I was planning to put a limit at each end of the X / Y axis and one on the Z at the top end of travel.
I get the fact that 24v may help to stop false triggers, and i understand what your saying about the time delay in the relay for homing.
EDIT : Just thinking about it and I'm not sure why I need 100% accurate homing?. What sort of inaccuracy with the relay are we talking about do you think?
I have never used soft limits and I never put jobs on that may go over the limit of the material / machine size. Plus I've got the limit switches on all extents of the travel should the worst happen.
5. How do these PSU's look for what i need. They are fairly small and the same size which i like.
5V 3A
http://www.ete.co.uk/power-electroni...y-5v-3-0a.html
24V 1A - 20Watts - You spec'd 30 Watts is 20 enough ?
http://www.ete.co.uk/power-electroni...-24v-1-0a.html
6. I will run 2 x 24v Fans with filters as you suggested. I have looked and an average 80mm 24v fan is about 0.2A.
Does the 24v relay use much current, if not then i may be ok with that 20 Watt 24V PSU?
If I can use those small power supplies then it may mean i don't have to scrap my case which would make me very happy. I will make that decision when i've got all the bits.
Top shout. Thanks again.
Martin
#1 No can't use it like you think but yes you can use latching E-stop if you have one.
The fact you asked this shows me you don't fully understand how this E-stop system works so I'll expalin by breaking the diagram down. (See Pic)
You'll see 24V+ (red wire) going to one side of the relay coil. The other side of the coil needs a path back to 0V for the relay to turn on and close it's contacts to turn things on.
So follow black wire #1 and you'll see it goes to first Contact of the relay. This contact is Open so the path back to 0v is broken and the relay can't turn on. So we need a way to provide temporary path to ground. This is where the Momentery Button comes in.
The Pink wire is connected 0V and runs to the NO Momentery switch which when pressed allows 0V to the other side of the Relay contact and provided the E-stop button is Latched on then the path is complete and the Relay turns ON and the Contact closes providing another Path to 0V.
Now when you release the Momentery button the relay stays latched ON using the new path until the path to 0V is broken again. IE Hitting OH Shite Button.
This means we created a Latching circuit so When you release the E-stop button the Machine can't just set off. The Momentery button is the safety and will only let the Relay Latch on again provided the E-stop button is Set. On more advanced systems you'd have all sorts of other safety checks, like door switches etc but the principle is the same.
#2 No you can use any fuse you like provided it's rated correctly.
#3 Something like this will be much better but call in and ask for relay with doide. Or Buy a diode from them and put across coils.
http://www.ebay.co.uk/itm/4PDT-POWER...IAAOSw-jhUB4V2
#4 Could share for homing has well using this setup but I wouldn't.!! If your happy to use Soft limts then forget Limits and just wire the Home switches direct to the BOB.
Limits are Nice, esp on small machine when first learning but on Med sized machine and with 3yrs experience then you'll be ok.
#5 Provided your total consumption isn't more than rated then you'll be fine.
#6 You'll be fine Typical relay pulls about 50 - 60Ma.
Attachment 16643
Martin I'm glad now that you have switched on your ears and are listening to the good people at last. Remember they are not trying to sell you anything so not biased.
.
Dean. Brill write up should be made as a sticky in a newbie section on the forum :toot:
Jazz
I now get your latching circuit now. Nice one.
I think you didn't quite understand what i was on about with the limits.
I DO want limit switches on all axis. It's easy to 'over jog' if your not careful.
I DON'T use soft limits. Well haven't up to now anyway.
I want 3 of my switches to double up as homing switches. Which i know how to setup in Mach3.
Just been looking at the KK01 breakout board wiring diagram (below) from CNC4YOU and it says you can use 24v with it for the limit switches as long as you add some 1.8K resistors.
Looks like i would have to add one in the Estop signal wire as well.
Attachment 16644
I think that would mean that I can do away with that second relay. I have modified your wiring diagram with what I think I can do.
See below. Make sense ?
Attachment 16645
I have made some more space in my enclosure. The 48V PSU now mounts on the outside of the enclosure back panel. I have made up a box with appropriate venting to enclose it. I even painted it the same colour. This will make a big difference to the space I have to play with inside.
I decided it was "Out of the box thinking". LOL
One other thing - been reading about relays and from what I can gather a 4PDT relay can be NC or NO depending on which terminals you wire to. Is that right ?
What u drinking - Guinness?
Thanks Jazz
Martin
Actually this is getting more complicated.
It looks like if you use that 24 volt input to the VCC in on the KK01 breakout board, you need to put resistors in the output to the drivers as well.
Think your relay idea might be simpler after all.
Would proximity switches be less prone to giving false readings?
And avoid the need for the relay?
And be more accurate ?
It looks like they are powered separately from the signal line.
Here's a link to the manual that shows the switch wiring.
http://cnc4you.co.uk/resources/KK01.pdf
Thanks
Martin
Martin The 24V line is only for the limits + estop. The driver signals are output from the BOB that will be 5V so no resistors needed.Quote:
Originally Posted by mturneruk
.
The Estop line to the bob is at 5V as it is isolated by the contacts of the relay (ie fed from the BOB through the relay contacts and back to the BOB) .
.
If you go with sensors then you would not need the 24V SPST relay but then to be safe I would put a 1k resistor in the signal line ( usually black wire) to limit current.
.
Re the 4PDT relay it can be used as normally open or closed depending which contacts you use on the relay.
Thanks Clive.
Ok. have done some more reading on using 24v for limits.
I will stick with the relay as per Jazz's diagram.
I assume using prox sensors will make no difference in accuracy terms for homing as it's the relay that is causing the inaccuracy.
I can live with that.
Thanks.
Martin
Have you thought about taking the VFD out of the box instead of the 48V PS.Quote:
I have made some more space in my enclosure. The 48V PSU now mounts on the outside of the enclosure back panel. I have made up a box with appropriate venting to enclose it. I even painted it the same colour. This will make a big difference to the space I have to play with inside.
I decided it was "Out of the box thinking". LOL
Yeah Clive. But it won't work so nicely.
This way the whole thing stays all as one unit with the controls for the VFD on the front.
I 3d printed the white cover, which when removed allows me to access the terminals without taking the box off completely.
Attachment 16649
Cheers
Martin
If your going to have Inaccurate home switches then there's no point having them at all really.! . . The whole point is accurecy and repeatabilty and you'll lose this thru a relay.
If the KK01 can accept 24V then it's simple just drop the relay and put resistor in series. It's the weak 5v signal that's the main issue so removing this removes the problems with sharing switches and complexity of using a relay.
If your planning on sharing switches for both then make it even simpler and make the Switches Travel with axis then sense adustable Targets at each end. This way only need 3 switches and one Input total.
Prox swithces are much better than Micro switches and cost about £1.50 so it's cheap as chips.!
Where can I buy Prox switches for £1.50?
Well here's one £1.40 http://www.ebay.co.uk/itm/LJ12A3-4-Z...kAAOSwvt1WQ~SRQuote:
Originally Posted by uli12us
Look harder and you'll buy several of them working out at roughly £1
Here's the very switch I tested to show how well they work on a router.
https://www.youtube.com/watch?v=A11Zvi3nAFE
Excellent. I like your idea that sounds better and much more accurate.
What confused me was this diagram in the KK01 manual showing that I might need to put extra resistors in the driver wiring as well if I was running 24v through the KK01.
That put me off.
Attachment 16653
Excuse me for being dumb again, what are the prox switches actually looking for - a magnet (target wise)?
I've looked and can't find any info.
Look what I got this afternoon - happy days!
Attachment 16652
My cousin cut them for me in his engineering shop.
The CNC mills he's got are serious.
They are perfect the bearings have dropped in beautifully.
So I can start building my machine now.
Thanks Jazz for your excellent input.
Martin
Strange, i have asked Ebay (but only for P. switch without sensor) and the lowest price was £3.60.
Nothing dumb in not under standing. Would be dumb if you didn't understand and Didn't ask.!!Quote:
Originally Posted by mturneruk
They are Inductive sensors so they sense Metal. You can get Sensors that detect Magnets Called HALL Affect sensors. Both are used to do the same job in different conditions.
Inductive are good for routers because no flying metal chips but on a Mill not so good.!
Talkiing about Different things there.! Drives use OUTPUT signals meaning they recieve signals being OUTPUT from the BOB.Quote:
Originally Posted by mturneruk
INPUTS are expecting to see signals coming INTO the BOB. They are different and separate to each other.
Maybe your asking the wrong question.!!Quote:
Originally Posted by uli12us
What you mean P switch without sensor.? PNP with no LED.?
The resistors are to limit the current going into the opto-isolators at the front end of the KK01. In crude terms, these opto-isolators are designed to accept 5V signals so with a higher voltage, you need to limit the input current to a safe value. It's a very straightforward and common thing to do. Those resistors will cost you about 3p each from your local Maplin so no exotic components needed!Quote:
Originally Posted by mturneruk
The KK01 needs 5V in any case; the 24V supply is just to feed the limit switches. As Jazz says, the KK01 will still give a 5V output to go to the drives.
In your link its "proximity sensor switch", I asked only "Proximity switch". But after the link, I entered the same in the shops question line and the only parts I found cost £2. Not really much more, but indeed a bit strange.
I have just ordered these. http://www.ebay.co.uk/itm/141781789185Quote:
Originally Posted by uli12us
I beat you by 1p Old boy . . . :loyal:Quote:
Originally Posted by Clive S
Are those NO or NC?
So those Prox switches that detect metal does that include aluminum which is non-ferrous?
Or is it ferrous metals only they are looking for . e.g. they contain iron.
Those prox switches your buying don't look to be shielded. Should prox switches be shielded or does it not matter so much?
I have just re-read your advice on the KK01 resistors. Thankyou.
Just to clarify are you certain that no resistors are needed going from the KK01 to the drivers, in the step, enable, dir wires?
I can't see why they would of put that diagram in showing different resistors, and I am certain that getting that wrong could be bad.
It's painting electronics by numbers at this end. Sorry for repeat question.
I'm getting my head round it slowly.
Manual : http://cnc4you.co.uk/resources/KK01.pdf
Cheers
Martin
Yes, it could be bad if you get it wrong! But look carefully at the table of resistor values in the diagram. You'll see that for 5V, the required value is zero. That is, a resistor of zero ohms. In other words, a piece of wire! That diagram is slightly misleading and in reality it comes from the data sheet of the driver rather than the BOB. The KK01 BOB is fed from 5V and cannot put out anything higher, so the diagram is misleading and there is no situation where you might need those resistors anyway. However, the drives are designed to take a 5V input and if you use a different BOB running at a different voltage you might need them. Just like the inputs to the BOB, where you need resistors if you use a 24V limit switch system but not if you work at 5V.
Neale. they are NO The NC one's are usually about £3-5 for some reason .Quote:
Originally Posted by Neale
Dean. You need the penny saved to have a piss (or is that 10p these days):victorious:
Martin. The leads are not shielded but I tend to cut them short and use shielded cable they also need ferrous ie just a bolt head or washer etc. Neale. I agree that schematic is very misleading you beat me to it:applouse:Quote:
Originally Posted by mturneruk
That throws me to another question. I have ordered a NO and a NC Sensor
from china, only to make the basket full. The NC is blue and the NO is orange.
I don't know if its alwas so, or can this made from each manufacturer different.
In many descriptions is the blue NC, I think thats correct because the sensors I have are in this way. But often enough they have a blue sensor and the description say NO. Is the description correct and the picture false, or have they different colours for the same sensor characteristics.
Jaz, I get only these offer from your 1.4 store
http://stores.ebay.co.uk/cayin35?_dm...+DC+6V-36V+NEW
the other with 1.41 don't send parcels to germany, so not to unusual, that I don't find it on german Ebay.
Oh, sorry, they give me the value in €, thats the same like £1,4.
But why I get €prices, from the british site.
I have both colours in NO you have to go off the numbersQuote:
Originally Posted by uli12us
Like Clive says forget colours that's not how they are identified. It's the last two letters that do that.Quote:
Originally Posted by uli12us
The Last Letter tells you if NPN or PNP. Second to last NO or NC.
NPN = X
PNP = Y
NO = B
NC = A
NO & NC = C (4 wires )
IE: BX = NO NPN
They will sense Aluminium but you have to get very very close and they are erratic so NO is the answer. Sense to a bolt head or Metal plate etc.Quote:
Originally Posted by mturneruk
Clive answerd that he does what I do.Quote:
Originally Posted by mturneruk
They are completely separate and isolated things don't worry.Quote:
Originally Posted by mturneruk