Auto Switch Off

Hi All

Has anyone thought about an auto off mechanism after the print?

Like there is a 4 hour print on now but I am going home now and will only be back in the office Monday morning. The print will finish, I don't have any worries about that, have left it printing 15 hours and many other prints and came back and was all good.
But now then the machine just stands on till Monday doing nothing...is this fine?

As long as the "end gcode" shuts down heaters, all should be good. Then again, even if heat is kept on for a long time, the risk that stuff should catch fire or whatever is likely very low, seeing as it usually doesn't catch fire when printing. It all depends on how paranoid you are and what you are afraid of, really.

You can use the ATX control if you are using the standard ATX PSU. I have made my own PSU control for use with a stand alone 12v supply, all this does is switch off the 12v 2 minutes after a print finishes. It does have a thermistor close to the output wires so it may prevent this from happening, but wouldn't help if the fault was on the input side.

Regards,

Les

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Pointy's Things
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I am not really worried about fire hazard...also sure the end code will run...more worried about it just being on but guess it should be fine...

It is a machine after all and they should just be able to be on...

I will be converting mine to Automaticaly Shutdown (Power Off) later today, as it's quite simple to do.

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Hi guys, well I did say earlier that you'd given me an idea so here's Part 1 of it.....
I'm doing this in small sections so people can follow it easier, and comment, and it's Bank Holiday here in the UK, and I need to go out.
Part 2 will be mounting the MicroSwitch, and adding the Gcode to Slic3r..

Purpose:-
To Auto Shutdown the Ormerod when the machine is finished printing...

How:-
1) We alter the settings in Slic3r to add a code to the end of the Gcode files to have it park the HotEnd/Duct some where out of the way near X0 and then lower the HotEnd/Duct on to a MicroSwitch.
2) The Power Off Signal will be via the Power Box PCB...
3) We fit two switches to the machine, to replace the LINK on the Power Box PCB. One switch is an Overide Switch (we want to be able to setup the Printer and start it printing, and use it as it is now). The other switch is the MicroSwitch the HotEnd/Duct will activate using the Park Gcode Slic3r adds on at the end of all the Sliced Gcode files.

So here's the pictures of HOW:-
1) We need to remove the LINK in the Power Box....
2) Here's what we will be replacing with....

The Overide switch can be any single pole Open/Closed switch. In the picture you will see I've used a Double Pole Double Throw Switch I had laying about... I'll use the other side of the switch to work a couple of LEDs to remind me of the switch position. The two wires to the MicroSwitch go to the COM (Common) terminal of the Switch, and the NC (Normaly Closed) terminal... i.e. When the HotEnd is away working the Switch is ON.
The two short wires coming from the Overide Switch go on to the Pins that the LINK was originally on......

Well that's ALL the wiring done..... Just got to mount the Switch in the next part, but I'm sure you guys will come up with your own ways of mounting it.
It's all wired in and working here, but I haven't mounted the MicroSwitch yet.
I hope that's helped a few people.
All the Best,
Kim....

Edited 3 time(s). Last edit at 05/25/2014 10:15AM by KimBrown.

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I guess it depends a bit on where you mount the microswitch, but if you print something large that is nearby you might not be able to lower the head down without hitting the print. Also, having to stay away from that switch would at least somewhat reduce the max print envelope. I would still much prefer doing it the "regular way" using a cable between the Duet and the power pcb, and the M80/M81 commands. Like this.

Just followed your link and saw the mod. I hadn't seen it before.
Not sure I'd like the idea of linking the Duet to the Power PCB here personaly.
You could be opening up a tin of snakes if you needed to claim on the warrenty for the Duet.
But glad it works for you.... I'll be sticking to my MicroSwitch.

Edited 1 time(s). Last edit at 05/25/2014 08:54PM by KimBrown.

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The duet is already connected to that pcb via a beefy 12V cable, the extra cable is a thin 5V one. I don't see why that would make a difference. And it is a feature built into the Duet, why would using that void any warranty?

Kim, instead of adding am extra microswitch, why not use the facility already provided for the Duet to control the ATX supply using the M81 command at the end of the print job? You can wire a push button in place of the link to turn the Duet on, and put a M80 command in config.g to keep it on until you have completed a print.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi DC, it's my preferance, as with people reporting Duet failures, I'd prefer not to link it to the Power PCB other than the 12V incoming supply.
Also, with my eye sight, I think there might be a risk of getting the connector around the wrong way should it ever come off.
I do like the idea of the M80 command, but I don't want to risk possibly damaging the Duet by getting it mixed up and then later having Rep-Rap say that it's not covered by the warrenty, and I have the switch all wired in now in any case. So I prefer the the switch option.

BTW On another point, I found that both ends of the main 12V lines had started to come loose on my machine due to vibration. One end was starting to burn. I also found that the 12V lines go in quite nicely in to the screw connections when the boards are out of their enclosures. I intend to add a dab on my young Ladies nail varnish (when shes not looking) to the tops of the screws to stop it happening in future.
Also I noticed before finding the loose connections there was quite abit of heat in the Duet enclosure, so I may well add a cooling fan if it's still warm after the other mods I'm doing.

At the moment the machine is in bits till tomorrow... But I hope to have it all finished then.

I did order a replacement Ally bed, but it hasn't arrived... If it's not here by tomorrow, then it will bounce back to the sender. I did ask them to send it first class, but I guess they didn't....

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Quote
KimBrown
BTW On another point, I found that both ends of the main 12V lines had started to come loose on my machine due to vibration. One end was starting to burn. I also found that the 12V lines go in quite nicely in to the screw connections when the boards are out of their enclosures. I intend to add a dab on my young Ladies nail varnish (when shes not looking) to the tops of the screws to stop it happening in future.

I suspect it's not that the screws have undone, but that the copper wire has softened and deformed due to the pressure and heat. I use 30A ring main cable (which is solid core) to connect the 12V supply to the Duet board, and since I switched to that I no longer find that the screws become loose over time.

Edited 1 time(s). Last edit at 05/26/2014 11:31AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

DC, if I go down the road of linking the Duet to the Power PCB, doesn't the power stay on the Duet when the M80/81 command is issued to shut down everthing?

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That depends on how you do it. If you power the Duet using J9 and on-board 12V to 5V converter. Then the main 12V will disappear using the M81 command. If there is no alternative source of +5V (e.g. USB or ext +5V) then the Duet will lose power. Also to get it going again then you need an external switch to bootstrap the +12V back on again.

I think the intended way of using this facility is to power the Duet via J10 (not J9) and with the +5V standby fed into the 3 way connector (GND, PSON,5VSTBY). That way the Duet remains powered all the time the ATX supply has power from the STBY supply. Duet power up effectively turning PSON and enabling the +12V supply. M80 and M81 can then be used to turn the +12V on and off. So for example one could put an M81 in config.g to start up powered off and then enable / disable +12V at the star and end of prints (with suitable time delays. I have had mine wired up this way right from the beginning with no ill effects as this was one of the intended ways for the Duet to work. I think the external 5V supply can be a bit cleaner than the on-board version.

Ok that sounds good then. I want mine to completely power down Duet and All.
If doing it this way will achieve that then I'll be a happy bunny.
Thanks guys.

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Thank you very much guys.....
It works a treat....
I had real problems with soldering in a header on the Duet thou, due to the solder resist, refusing to come away cleanly.... Probably a good thing.
It would be really good if there was a timer M or G code, that could be used to allow the HotEnd to cool down before shutting down.

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Kim, as I attempted to describe in my earlier message, you can have M81 power down the Duet completely. Just power the 5V supply from the 12V as usual. Then to start it up, you need a push button wired between ATX ON and ground (i.e. where the link is on the ATX power PC, and an M80 command in config.g to keep the power on when you release the push button.

You can use the G4 command to program a delay before the M81 command.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi DC, thank you, yes that's exactly what I've done, but didn't know about the G4 command. I'll look it up, once I have the Ormerod setup for the home network....
I've tested it, and it all shuts down a treat thanks.
I will need to print another powerbox print thou, as the buttons I have are metal cased, and might short the dropping resistors for the led.
Traveling, means it setup to my phone network at the moment. Now I'm home I need to alter it, and then in a few days alter it again, so ending up with 3 variants of config.g.....

Suggestion....
M81 with a parameter, could invoke a timer, if the G4 command is already in the Firmware it could pass it to that routine.
It would be a very neat way of doing it.

Kim...

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Oops! I spoke to soon.

Ok, where have I gone wrong here...
I wanted the machine to TOTALY power down when the M81 command was entered.
Instead the fan goes off, starts to spin down and then powers back up.
I have to press the button I've added to start it now, which is correct.
I've replaced the link on the power supply PCB by linking it to the Duet using Gnd and Pwr On link under the 12V incoming terminals. I've left the +5V disconnected, as I was expecting the Duet to power down when the 12V went off.
And I left the J9 link in place to get 5V from the 12V main ATX supply.
I'm running it via the Web browser, so it's not getting power from the USB...
And using DC's 59a Firmware.

Any one got any suggestions please?

Edited 1 time(s). Last edit at 05/26/2014 07:55PM by KimBrown.

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Quote
dc42
Kim, as I attempted to describe in my earlier message, you can have M81 power down the Duet completely. Just power the 5V supply from the 12V as usual. Then to start it up, you need a push button wired between ATX ON and ground (i.e. where the link is on the ATX power PC, and an M80 command in config.g to keep the power on when you release the push button.

You can use the G4 command to program a delay before the M81 command.

I tried removing the M80 command from the config.g file, but I'm going to guess that after the M81 command has been processed there is still enough power in the boards capacitors to keep it alive.
There clearly is a blip in the power, as I can hear it in the HotEnd fan, so it's trying to work, but it's not long enough to drain the power out of the board circuit, so the board wakes back up.
So I think that when it hits the M81 routine, there's no delay before exiting the routine. If there was a 10-15 second delay in the routine, which probably wouldn't complete as during that time the power would be drained, then this would work.

So to achieve a complete shut down means me going back to my MicroSwitch system, as I don't want the Duet powered up at the end of a print. I want it completely powered down.

I also tried having M81 at the start of the config.g file, thinking that at start up the button would be pressed and the M81 command would have no effect. This just made the board oscillate, on and off...

Edited 1 time(s). Last edit at 05/26/2014 10:29PM by KimBrown.

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It looks like the Duet may be going into an unpredictable state when the power goes down. This is something that can be adjusted in firmware. I'll take a look at it when I get time.

btw you should not connect another ground wire between the Duet and the ATX board. If your main ground wire becomes disconnected or the screw terminal works loose again, you will get large currents flowing through that extra ground wire, which those terminals are not designed for. A single wire from PS_PON to the centre pin of jumper K1 should be the only wire you need.

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Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi DC, yes I'd forgotten about that. I'll disconnect it when I get time later. I'm thinking it could be the capacitors in the power supply keeping it alive long enough for it to carry on running.
I'll try shutting it down with the bed heater on later.

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Yes the capacitance in the PSU will keep the fan turning and the Duet powered for a little while, but that shouldn't be a problem. I think the problem is that the SAM3X is not powering down cleanly and is pulsing the ATX power output pin, turning the power on again.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Oh, so it's not just a problem here then. I'll try the M81 command while the HotBed is on in the mean time. I want the Duet to shut down totaly due to the printer being in the cabin at work, as well as prefering the idea of it being off if I leave it printing while out.

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I don't know if it's just a problem with your system or not, but I'm guessing not. I'll check my system out with a scope sometime. There is a chance that the problem is being caused by capacitive coupling to the PS_ON wire. If that's the case, then connecting a resistor between PS_ON and +5VSB may help - that's between the centre pin of jumper K1 and the one next to it that the jumper wasn't on originally. A value of between 200 ohms and 1K would be about right.

Edited 2 time(s). Last edit at 05/27/2014 05:17AM by dc42.

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The PSU is switched on when the power signal is low. It can therefore only be controlled from a genuine open-collector (or otherwise isolated) output from the switched board. Any type of output from an I.C. will usually have protection diodes which will conduct to Vcc when Vcc drops. Vcc is low (because the board is powered down), and so it will turn the PSU back on. Some circuits also have a protection diode or a resistor to Vcc on a transistor buffered output, which will thus have the same problem (I've not looked at the Duet's schematic in that respect). If the output is truly open collector, you should place a low value resistor in series and a capacitor on the PSU side to catch glitches that may occur when the Duet's Vcc ramps down - most digital circuits will glitch unpredictably as they brown-out. The resistor must be low enough to provide a solid low against the pullup on the PSU when the transistor is switched on, yet be high enough to suppress glitches in conjunction with the capacitor. If the glitches are long enough, it may not be possible to suppress them without other circuit modifications.

When looking at circuit operation, assume that the Vcc of a board that is powered down is connected to ground - thus all pullup resistors (to the unpowered Vcc) become pulldown resistors.

Dave
(#106)

Dave, I had already checked the nature of the PS_ON signal on the Duet. It's an open drain output from a BSH105 mosfet. There is no pulldown resistor on the gate, however I would have thought that the capacitance of the mosfet should keep the gate near enough to ground for a little while, even if the SAM3X output goes to the high impedance state as it powers down.

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Quote
dc42
Dave, I had already checked the nature of the PS_ON signal on the Duet. It's an open drain output from a BSH105 mosfet. There is no pulldown resistor on the gate, however I would have thought that the capacitance of the mosfet should keep the gate near enough to ground for a little while, even if the SAM3X output goes to the high impedance state as it powers down.

Assuming there is no pullup (to Duet Vcc) or diode on the drain, what is most likely happening in that case is a high-going glitch on the mosfet's gate as the CPU loses power. As said, a simple RC filter can fix this so long as the glitches are short-lived. It is better to put the filter on the gate, but it often works on the output. As this signal will never need to pass short pulses, you could fit a series resistor of 47 ohms (which should be small enough to bring the signal sufficiently low when enabled) followed by an electrolytic of 10uF or so to ground on the PSU side. Firmware fixes are not possible because the glitches are usually due to logic gate brownout failures rather than a program crash - the gate capacitance doesn't help because during the glitch it is being actively driven (albeit from a falling Vcc) rather than being left high-Z. Unfortunately the internal logic failure during brownout is unpredictable, so one CPU can behave differently to another, meaning that other people may not be able to reproduce the issue. A bleed resistor across Vcc will prevent it floating much above ground for a long time - when the voltage drops below that needed to maintain the various oscillators, current draw of a board can sometimes suddenly drop to something extremely small, allowing the reservoir caps to maintain a voltage of a volt or two for a very long time - which will appear on any output that is stuck high and be sufficient to keep a mosfet turned on for seconds or even minutes. In that case filtering won't help at all!

Dave
(#106)

Dave, I agree that there is probably a positive-going glitch on the gate. The reason I think a firmware fix may be possible is that the SAM3X has an option to assert the reset signal during brownout, and that might prevent the glitch.

Edited 1 time(s). Last edit at 05/27/2014 01:09PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
Dave, I agree that there is probably a positive-going glitch on the gate. The reason I think a firmware fix may be possible is that the SAM3X has an option to assert the reset signal during brownout, and that might prevent the glitch.

Understood. It might do, depending on the internal circuit of the CPU. Is the reset signal not asserted during a brownout anyway by the Duet's reset circuit? I almost always use a reset chip that will assert a global reset if any voltage drops below a pre-set limit, which in my opinion is vital on any board that has more than one power voltage. Such chips cost pennies.

Dave
(#106)