What Trick.?Quote:
Originally Posted by eurikain
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What Trick.?Quote:
Originally Posted by eurikain
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.
Attachment 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.
Attachment 17265
Note that my VFD is completely separate (separate mains cable, shielding and earthing), but many people run everything off one socket.
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).
Correct works exactly like that. Very simple.Quote:
Originally Posted by eurikain
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
Very simple but not obvious for me haha ^^Quote:
Originally Posted by JAZZCNC
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 ?Quote:
Originally Posted by routercnc
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.Quote:
Originally Posted by JAZZCNC
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.!Quote:
Originally Posted by eurikain
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.!!
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.Quote:
Originally Posted by eurikain
Cheers,
Rob
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
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.Quote:
Originally Posted by cropwell
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.Quote:
Originally Posted by Clive S
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.. :(
I was not intending to use panel control, but speed and direction control from the CSMIO-IP-S.Quote:
Originally Posted by JAZZCNC
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
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.!!Quote:
Originally Posted by cropwell
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.
Your understanding is correct.Quote:
Originally Posted by cropwell
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'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.Quote:
Originally Posted by eurikain
Jazz, you're the best :DQuote:
Originally Posted by JAZZCNC
Here is my BOB's manual (I find it not too clear):
User Manual of 5Axis Breakout Board - Mach3
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 :) !!
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
[ATTACH=CONFIG]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)
Attachment 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 :DQuote:
Originally Posted by JAZZCNC
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.Quote:
Originally Posted by eurikain
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 ? :)
USB can't be trusted, but it isn't as bad as USA.:joker:Quote:
Originally Posted by JAZZCNC
On a serious note, USB ports on a computer have a very low current sourcing capability.
Go to bed Rob, you're tired :DQuote:
Originally Posted by cropwell
True, but you can still use the port if you power it with an external PSU :)Quote:
Originally Posted by cropwell
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.Quote:
Originally Posted by eurikain
Cheers,
Rob
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.
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 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.
I see what you mean :) That's right, it's a matter of opinion.
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?
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.
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.
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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.Quote:
Originally Posted by routercnc
It will be a toroidal transformer 25-25v AC in series or 50-50 in parallel MCB D typeQuote:
Originally Posted by Tom J
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
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)Quote:
Originally Posted by routercnc
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.Quote:
Originally Posted by Tom J
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
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
Attachment 23315
John
About the diodes across the fuses for stepper drivers..Quote:
Originally Posted by john swift
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
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.