Electronics for New Machine + Chinese Spindle + VFD

[JAZZCNC]

As there are 2 power inputs into the box, the fuses are built into the 10A Chassis power input sockets. Not sure why i would need any more.

Why do you think each electrical item in your house has it's own fuse.? Why not just rely on the Main Breaker in the consumer unit.?
Think about and it's obvious.!!

I am confident i can wire it ok.

The above statement contradicts this slightly.!!

Yes E'stop mounts on the front and wires into the breakout board directly. However you've made me think now about E stopping the spindle as well.

Wiring to the BOB is Not Safe. EMERGENCY STOP is exactly that and should remove all power when pressed. Wiring direct to the BOB is only in forming Software to stop the program or at best drop Motor outputs which isn't safe.
Correctly done then E-stop will remove power to every electrical item so VFD is included. Don't confuse E-stop with Limits etc they are and should treat different.
Creating a Safe E-stop isn't difficult or expensive so there no real reason why not to do it correctly.

Obviously if i could get away with using this box i would like to as i have bought it now.

I was planning on having male / female screw on glands on the front of the box for the steppers to connect to, so the box can be separated.

Just seen this which is even tighter.
http://s26.postimg.cc/3rqeewhcp/image.jpg

However he has got partitions which i think is a good idea.

Martin just because someone else has done it wrong doesn't mean you should too.!! . . . What he's not saying or maybe not aware of YET is that the Heat is killing his drives slowly and there life span will be considerably shorter in there unless he's got Lots of Cooling.
The potential for problems is hugely increased due to heat, missed steps, low performance strange lock-ups and all sorts of other wierd and wondeful thigns can happen because of heat and the often new CNC users arnt even aware of them because they know no different.
When the reality is there machine is being strangled in some way or they waste money buying bigger motors or drives etc thinking there missed steps or rough running motors is due to them when it's not.

Heat sends Electrical items Bonkers at best, Kills them at worst.!!

Space for EMF isn't such a big deal provided Grounding is correct and routing of wires is done sensibly

My advise is look around at what others have done or ask and LISTEN to what is said by experienced builders. Then do it correctly and don't cut corners other wise it will cost you more money in long run and be painful experience in the process.!!

[mturneruk]

Jazz. Obviously I am listening. I am reading every word 5 times!
Obviously I am working within a budget, but I want to do things safely, and I admit I no electronics engineer, so i am asking for help...

I still can't understand the need for additional breakers or fuses in the box when the chassis power connectors have fuses built in.

On my last machine i had the E-stop wired to my BOB, however i was using a router which had it's own on / off switch. The VFD seems to of complicated everything massively.
So i would appreciate you telling me how i could wire a safe E-Stop.

Chatting to that chap about his cramped case, he said he had 2 48V fans which keep everything cool and it had all been running fine for 2 years plus.
I was thinking i would do the same.

None of you are saying i would have an EMI issue, rather more a heat issue which should be able to be controlled with fans, should it not.
Thanks again.
Martin

[JAZZCNC]

I still can't understand the need for additional breakers or fuses in the box when the chassis power connectors have fuses built in.

Ok Ill explain. So your Incoming Chasis power has you call it is providing power to the drives which all pull a certain amount of current. Lets say 4A each then you have other items possibly pulling off it taking few amps more so your Incoming suppy needs to be fuse rated to handle all this load plus a little spare so it will probably have 13A fuse.
Now what happens if say one motors blows up and shorts out.? Then drive will Pump current to that motor upto the Max the PSU can provide or until the fuse blows which will be much more than 13A. Now the drive is only rated upto 7A so it goes up in flames.!!! . . . Well not really but it does release the Magic smoke and your out of Pocket £50 just because you didn't fit a 50P fuse.. .

I will help you to do this correctly but I'm a little busy just now but I will come back with a Diagram to help.

Edit: Give me a list of everything your putting in the Case.

Regards Space then yes it's mostly heat related so if your sure you can remove the heat correctly then fine but just because he's not had problems doesn't mean you won't. Electrical components need a certain amount of air flow to cool correctly and any restrictions on cooling will have an affect long term. Or on performance.!!

[njhussey]

The E-stop through a relay can also send a signal to the software to shut things down. It's really bad for the VFD if you just cut the power in full flow, could damage it.

I've had them all running from the same socket but only for testing, not doing any serious cutting.

[njhussey]

In an ideal world you run power down one side and signals down the other. There are lots on this forum happily running everything together. If your power cables and signal cables are all shielded then it should be fine.

[JAZZCNC]

Yes it's fine and if it's water cooled Spindle just try to put the water pipes between signal and power cables. Provided you have correct grounds then you shoudln't have any troubles.

Edit: Doh didn't see neils post.! . . Same What he said. . .Lol

[njhussey]

This is what I love about this forum, so much information on so many different topics by the members :)

[mturneruk]

God forbid - If the worst should happen with my machine and for what ever reason the sensors didnt read the end stop position or user error, what do you think would give first. Steppers ? Can't see the frame breaking.

[njhussey]

Your trousers......;)

[komatias]

yeah I agree, your trousers would be needing some attention.