[poorfarmer25]

Hello I am wanting to add a ups to my router table, the problem is my spindle is run off 220. Is there a way to trigger an estop if power is lost? I had thought about using a 5v wall wart plugged into the wall as an input to my bob will this work or is there a better way to go about this???

[keebler303]

A "feed hold" may be better than an e-stop, but that is your decision.

I'd recommend buying a UPS with a relay contact. Lots of UPS's have them. You can feed that into mach3 to signal a power loss. It will react faster than a wall wart. If you are drawing very little current, the wall wart may stay powered for several seconds after power outage due to capacitance.

If you merely want to stop the feed when the spindle stops, you can simply add a relay to the power cord to the spindle so when the spindle is running, it gives a "spindle good" signal to mach and when the spindle shuts off (due to power outage, fuse blown, you trip on the extension cord, etc.) it will signal to mach that there is a spindle fault and mach should halt motion.

Matt

[poorfarmer25]

Feed hold sounds like a better idea, Can you recommend a relay that I could use for this purpose and what the name of the signal would be on ports and pins?

[keebler303]

If it is signaled from the UPS, you would use its builtin relay and wire it much like a limit switch.

If you want to wire it to the spindle power, you just need a relay with a 220V AC coil. This would work fine (you need a socket to go with it) QL2N1-A220

This may work for you to feedhold, although it may be useful to set it up differently so you can tell the difference between a user initiated feed hold and a power fail initiated feed hold. Ideally you would want to keep the machine from moving until the spindle was powered. I am not sure if this method will do that.

I need an external switch/input to cause a FEEDHOLD condition in Mach3

Matt

[keebler303]

You could also handle the logic in mach with a macropump, it would be a bit more involved but you can add custom messages like "Spindle power failure" or similar so you know what happened (not that it wouldn't be obvious).

Mach 3 CNC Controller Macropumps Intro - YouTube

Matt

[poorfarmer25]

Thanks a lot for the info I really appreciate it! The simplest thing to do would be to get a ups with relay, but all the ones I have found are 200+ bucks just for the interface card. Am I correct that relays can work backward like the motor starter? high voltage tripping the low voltage input instead of vice versa ?

[keebler303]

A relay is a coil which moves a set of contacts to make or break an electrical circuit. The relay will not switch anything unless the coil is energized.

To switch a 12V circuit with 220V AC, you need a relay with a 220V AC (or 230, whatever nominal voltage is) coil.
To switch a 220V circuit with 12V, you need a relay with a 12V coil.

They do not work backwards.

A feedhold signaled from the spindle will actually better protect you as it will stop motion in the event of a blown fuse or breaker, which a UPS would not see as it would likely be on a different circuit.

I could provide some hints if you tell me what your spindle actually is. Is it a high freq spindle, a router, what?

Matt

[poorfarmer25]

Sure i'm using a 2.2 kw spindle with Hitachi vfd which is set to use as an external on off switch that goes through the relay on my board, its not the right way but I am not smart enough to wire it up correctly.

I had though about using the ups software to issue a halt command however I don't think that would work reliably with that driver watch thing running and mach having resource priority.

[keebler303]

OK, that actually makes it easier. You likely do not need a relay and can use a digital output from the VFD itself.

Can you give me the model number or a link to the manual?

[poorfarmer25]

Hitachi x 200 http://www.clrwtr.com/PDF/Hitachi/Hi...ser-Manual.pdf
On page 39 it has an alarm signal maybe I could use that?

[keebler303]

You could use the alarm signal. If power is lost you will first get an undervoltage trip, which should activate the alarm signal.

It may respond more quickly if you use the Frequency Arrival Signal. This signal is true (logic high) when the spindle is at the desired speed. It is false (logic low) when it is stopped, accelerating, or decelerating. This means that the output will only be true if the spindle is up to speed. Regardless of what error the drive encounters, that output should tell mach when the spindle is not at speed.

If the spindle is stopped (you forgot to turn it on maybe) there will not be an alarm signal so mach won't know the spindle is stopped and will try to cut with it anyway.
If you use the frequency arrival signal, mach will know the spindle is not up to speed and can be configured through a macropump so that it will not start a cut without the presence of this signal and it will feedhold or estop if that signal is lost sometime during the cut.

You'll have to setup the parameters so you get that output and then figure out how to tie that into your breakout board. It is probably simplest to use the onboard relay that the drive has.

Matt