Controlling spindle direction through relay

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LenelyWolf
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Re: Controlling spindle direction through relay

Post by LenelyWolf »

polaraligned wrote: Mon May 03, 2021 8:17 am Not up on Acorn as I use Centroid DC servo drives, but if the Acorn relay output is a mechanical relay driving another relay, it is fine. You will only be drawing a handful of milliamps to close the other relay.

As for item #2, time delay relays are readily available.
I don’t know if acorn relay is mechanical or not but I only need the acorn relay to switch on big relay. I’m not sure if I can run full 5amps from 24V supply through that relay to switch the big relay

#2 i really don’t want to use time relay because the time vary and it depends on if the spindle is loaded or not and what rpm it is running. I was hoping there is some feature in cnc12 to disable vfd on spindle direction change until rpm from encoder are 0. Then enable vfd and change direction.
martyscncgarage
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Re: Controlling spindle direction through relay

Post by martyscncgarage »

polaraligned wrote: Mon May 03, 2021 8:17 am Not up on Acorn as I use Centroid DC servo drives, but if the Acorn relay output is a mechanical relay driving another relay, it is fine. You will only be drawing a handful of milliamps to close the other relay.

As for item #2, time delay relays are readily available.
Agreed, I would use a separate small power supply than the Acorn logic power supply to power relays, like your reversing relay, estop relay etc.
You do need to use some sort of timer relays to ensure the spindle has come to a stop. The Lenze document says it uses dynamic braking so perhaps that time won't be long. You might experiment with putting a G4 Px in the the first lines of the M3 and M4 Macros G4 is a Pause. Px (x is the number of seconds). The Pause would time and then fire the output.

Rigid tapping likely won't work with this arrangement....

Marty
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polaraligned
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Re: Controlling spindle direction through relay

Post by polaraligned »

LenelyWolf wrote: Mon May 03, 2021 8:29 am I’m not sure if I can run full 5amps from 24V supply through that relay to switch the big relay
Just because the power supply is rated at 5 amps doesn’t mean you will be putting 5 amps through the relay. The relay will only draw whatever it’s coil is rated at. Look up the specifications on it and you will know. A couple of hundred milliamps or less.
LenelyWolf
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Re: Controlling spindle direction through relay

Post by LenelyWolf »

Yeah main reason to wait for the spindle to stop was to be able to rigid tap on the machine
martyscncgarage
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Re: Controlling spindle direction through relay

Post by martyscncgarage »

polaraligned wrote: Mon May 03, 2021 10:54 am
LenelyWolf wrote: Mon May 03, 2021 8:29 am I’m not sure if I can run full 5amps from 24V supply through that relay to switch the big relay
Just because the power supply is rated at 5 amps doesn’t mean you will be putting 5 amps through the relay. The relay will only draw whatever it’s coil is rated at. Look up the specifications on it and you will know. A couple of hundred milliamps or less.
Polaraligned is correct. Relay coils don't take much current.
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
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LenelyWolf
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Re: Controlling spindle direction through relay

Post by LenelyWolf »

Yeah I also thought so.. i just wanted to confirm that. I don’t want another fireworks on my acorn 🤦
martyscncgarage
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Re: Controlling spindle direction through relay

Post by martyscncgarage »

I'm concerned your spindle de ve does not provide isolation on the analog inputs. I have seen drives with no signal isolation blow up Acorns. You should call Lenze and leave the analog signal disconnected until you know for sure.
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
LenelyWolf
Posts: 85
Joined: Sun Jan 17, 2021 3:13 pm
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Re: Controlling spindle direction through relay

Post by LenelyWolf »

martyscncgarage wrote: Mon May 03, 2021 12:23 pm I'm concerned your spindle de ve does not provide isolation on the analog inputs. I have seen drives with no signal isolation blow up Acorns. You should call Lenze and leave the analog signal disconnected until you know for sure.
Actually I believe that is the main reason for the fireworks and also reason why I’m getting 90v on my ethernet shield and ground. There used to be isolation board originally installed but I think there is no way to connect it back with acorn. Also people who converted this machine to mach3 didn’t use this isolation board and the had no problem so I thought it well be the same for acorn..
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