@ Silyavski, thank you very much for taking the time to go thru my VFD manual to help me. I think I'll get it going now and I will also connect the VFD failure relay to my EStop circuit.
@Neale, Ahh, thx, now that makes a lot more sense to me. I can now see why one would use this. I guess emulating the functionality by using a few relays that drop out on estop would not be impossible but getting the reset functionality to work would be very difficult for me, so it would be a lot easier to just use a component. Had a look on RS-online but new they are expensive so I'll try and find a second hand or discontinued one from a seller thas will to send here. Just wondered why on earth they call some models a PNOZ, do they know what it sounds like when you pronounce it in english :-)
@Eddy, thanks that's a very useful link.
BTW you guys were right, I did a cad layout of my control box this weekend and its MUCH larger than I thought if I follow the component manufacture's guidelines for spacing between parts. I'm going to need a small lotto win to complete this machine if I want a nice PNOZ, a steel enclosure and a CSMIO/IP-M. Scratching around to see if I can't maybe liquidate some other redundant hobby stuff :-)
Just thought I'd post an update. My build has been delayed a bit mostly due to lack of budget but I finally got going again. Got lucky and a friend contacted me to cut 6 x bench-rest rifle stocks which helped a bit for the hobby cash-flow. My stock making hobby is what what got me into cnc in the first place :-) Here's a pic of one getting cut
Anyway back to the topic. Got a nice 800x600x220mm steel cabinet for a very reasonable price (+- 70GBP). I was concerned about my ability to cut holes etc in the steel but got it done relatively painlessly using a Dremel and those small clip-in cutting disks.
I cut a alu panel to replace the steel one that came with the box.
I made an air filter box with a cheap car filter to house my huge fan and keep stuff out of my control box.
I think I have figured out what I want to do with my wiring. I'm a bit further along but these were the last photos I took.
WHOOHAA, its running!
Finally completed my control box. Decided to chuck 4 of the safety circuit relays and replaced it with an Arduino which resulted in a simpler overall setup. E-Stop button works as expected and any fault or position loss will stop all motion.
Steppers now mounted
Have to do the wiring of the machine now, fit cable chains, zero and limit switches etc but could not resist to try a few test cuts. No machine bed yet so I just clamped a vice on a few blocks of wood. Took a lot of effort to get this far but thinks are finally comming together and I'm absolutely over the moon with how the machine cuts. Part below was cut 15mm deep with a 6mm HSS endmill at 1000mm/min @ 3mmDOC and finishing cut at 500mm/min and 6mm DOC.
Thanks Jazz. Apologies, that came across wrong, ill try to explain. I wanted any fault signal to disable all movement and I could not figure out an easy way to combine the 4 stepper driver fault signals into one so I got them to switch 4 small relays and then wired the relay switches in serial so if any one opens it cuts my 5v enable circuit etc.
There are probably better solutions but I replaced those 4 relays with the arduino using 4 inputs and 1 output. Arduino Inputs connected to stepper driver fault outputs and the 1 output connected to all driver enables and spindle relay. The few lines of code check the inputs and if any change is detected it takes the output pin low disabling all drivers and switch the spindle off. Ive tested this to death and it works like a charm.
Not sure I understand what you mean about the spare IOs. I do have spare inputs available on my controller but i dont want to rely on mach3 alone to stop everything or is that not what you mean?
I think what he's getting at is how u had it setup with the 4 relays, why the need for Arduino, are you then doing somthing else once a fault is detected?
Mechanical vs Digital I guess.
Last edited by Lee Roberts; 15-06-2015 at 10:56 PM..Me
Yep, Lee I had one relay per driver with the fault signal driving the relay so a fault on any driver would open that relay which would break my enable circuit which ran in series thru the 4 relays + spindle fault relay. So you are correct, I just replaced the simple logic that the electro-mechanical parts performed with digital.
Please keep in mind I'm very much a noob when it comes to this electrical and electronic stuff so how do you gents combine these sinking type stepper fault signals?
Last edited by mitchejc; 16-06-2015 at 01:46 PM. Reason: hit send too soon
Regards the Drive fault signal and Relay then you only needed 1 relay and wire the drive fault signals in parallel so if any drive faulted it turned on the relay. The relay NO or NC contacts would be used to control other things like E-stop relay and send signals to control saying fault happened.!! . . . Much safer.
Last edited by JAZZCNC; 16-06-2015 at 04:04 PM.
The Following User Says Thank You to JAZZCNC For This Useful Post:
Thanks for the advise, Jazz. Keep in mind we rely on computers for safety all the time, in fact in some cases we use computers to make mechanical things safer :-) I do not really agree with you comparing an arduino with a pc as they are worlds apart in terms of complexity and things that can go wrong etc but its not a topic I want to labour.
I believe what you are trying to get across is that the relay solution is ultimately more reliable and I'd still like to get that working if possible. I thought this was going to simple as pie and its not like I did not try and I spent more than a full day to get it working and failed to do so reliably. My challenge is the following: Fault output on the driver is a sinking type output. I connected it as per the manual with a simple little 5V circuit containing only a current limiting resistor and I got 0.7V on the driver fault output pin when in fault and 4.7V when not. I can swap these around in the driver setup when I set fault to "active high". I used this setup with a small relay board that basically contains a transistor and a diode but it switches even at 0.7V and its at that point where I started fiddling and burning time and eventually chucked in favor of the simple arduino setup which I got working in 30mins. So what's the right way to do this? Can you perhaps please help me out with a description or diagram or close-up pick of your fault signal setup if you are using Leadshine drivers?
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