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After much hair pulling I think I have finally started getting my head around some of this electronics! Please could you guys cast your eyes over the attached schematic for me to ensure I don't see any of this rumored 'magic smoke' come from the electronics, or worse yet...my head?!
Most of its based on a circuit diagram Dean posted for another user a while back and connections based on various instruction manuals and confirmed against Joe's schematics. Some things I was unsure about were things like daisy chaining some of the wires (eg at the fuses/terminal blocks), if connecting shield wire earths in series on the limits was OK and if the alarm terminals on the drives only applied if using a safety relay?
Also, I know you recommended 6.1Nm NEMA 34 for the X axis but would I be OK going with the 8.7Nm instead as per Joe's build? As this would let me buy all motors from one supplier (CNC4YOU). Thanks.
Last edited by examorph; 09-12-2016 at 12:04 AM.
Forgot to mention, would the below enclosure setup be OK? I think I read somewhere that 600 x 900 was the typical recommended size for enclosure so will look for this, does anyone have any recommended suppliers please?
Also, will this do for the drives: https://www.aliexpress.com/item/New-...2-5560f2d46d31
Or does anyone again have any alternative recommended supplier? Thanks!
Last edited by examorph; 09-12-2016 at 12:05 AM.
6x8x3 would meet the needs of most I think: http://uk.rs-online.com/web/c/enclos...ng/enclosures/
Try and keep all power cables away from communication cables as best you can, use cable trunking to define 'zones' and then group components in each zone
Last edited by Lee Roberts; 05-11-2016 at 01:58 PM..Me
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Will look at this properly for you later but see one thing I'd change. Use contactor rather than relay contact for turning on transformer. Still use relay for safety but have turn it on contacter which is better suited to high current.
Also what kind of limit switch are you using.? On quick look if Proximity then think you have them wired wrong. If Prox what type NPN or PNP.?
Another thing I noticed I had cocked up on was showing them as "limits" on the diagram, they are actually homes and I was planning on using soft limits within Mach3, will get the drawings updated showing this and the contactor. Thanks
EDIT: Is it also worth running the VFD through the same contactor as the transformer or should I keep that one running through the relay?
Last edited by examorph; 05-11-2016 at 03:14 PM.
Ok had good look and only see few things would change.
First home or limits makes no difference to how wired and you had it wrong. See pic how to wire Npn correctly.
Now if you have the switch travel with the axis and sense target you can have one switch work has home and limits for that Axis. Just few settings inside mach3.
Regards the VFD then yes it would be better run thru contactor than Relay contact.
However personally I wouldn't Kill power to VFD just sending it stop signal is enough IMO. While strictly it's safer to Kill power it's also pain in the arse waiting for VFD to power up just because you put machine in Reset mode. It's personal thing really but IME it's more trouble than it's worth and spindle being forced into stopping is safe enough at DIY level. The Controller will also drop the Spindle output so stops anyway when E-stop occurs.
Next I would control the Water pump using the VFD on board Relay. This way the pump only comes on when spindle is spinning.
Fuse sizes for drives are too large. 5A is more than enough.
Edit: Noticed on pic forgot to change input numbers but you should get the picture.
Last edited by JAZZCNC; 05-11-2016 at 08:07 PM.
Thanks Dean, drawings almost updated but I am still struggling with figuring out how to wire the water pump direct to the VFD on board Relay
Also, after searching many posts I noticed that most people seem to be using a pump ran off of mains voltage instead of 24VDC as shown, so would something like this be more suitable? http://www.ebay.co.uk/itm/2000-L-H-W...3D390532181450
If so, how would I wire it direct to the VFD so that it has mains supply only when spindles running please? Thanks.
If using a small mains pump, as i do, use a separate relay to control it from the vfd.
The vfd has a relay - you need to set the parameter which turns this on when the vfd is in the 'run' condition.
Next, feed this relay a 24v supply to the 'com' or common contact, then from the 'n/o' or normally open contact you go to the +(if marked) terminal on your pump relay, the - terminal then goes back to your 24v supply.
Now you have a separate relay which turns on with the vfd. The relay will have common and normally open contacts - feed a fused live supply (1A or 2A fuse) into the common, then normally open to your pump, other pump lead back to neutral.
That should be it :)
The reason i would do this is for isolation - i don't like having 240v mains anywhere near the logic side of the vfd terminals.
Exactly like dave says but here's pretty pic just in case. Don't forget to change VFD param.
If you do end up using 24Vdc pump you can Dump the Extra Relay just run 0Vdc thru FA FB terminals straight to pump.
Last edited by JAZZCNC; 06-11-2016 at 09:12 PM.
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