Printing with USB cable un-plugged

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XRay
Posts: 30
Joined: Mon Mar 26, 2012 6:06 pm
Location: Mississauga, Ontario

Printing with USB cable un-plugged

Post by XRay » Tue Jul 10, 2012 8:11 pm

I tried to un-plug the usb cable after printing starts to solve my previous problems and it seems working well so far. But I still have these questions:

1. In which way un-plugging usb cable affects printing process?
2, Is anyone who has been printing with usb cable plugged without any problem?
3, Is this software or hardware related ?

Thanks.

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wilsonj
Posts: 569
Joined: Tue Feb 28, 2012 10:26 pm
Location: Australia

Re: Printing with USB cable un-plugged

Post by wilsonj » Tue Jul 10, 2012 11:00 pm

It appears its possible for spurious information to be sent from the PC during printing. This can cause the extruder to stop.

On quick prints I'll sometimes leave the USB plugged in. Although I haven't found any pattern to when it happens. Best just to unplug it.

Not sure if its hardware or software.
Regards
Jamie
3DPrinterGear.com.au

mr6k
Posts: 327
Joined: Tue Feb 14, 2012 11:47 am

Re: Printing with USB cable un-plugged

Post by mr6k » Wed Jul 11, 2012 9:46 am

In the 8 months I have been using the printer on jobs running up to 7 hours I have never unplugged the USB and never had a problem; having posted this I will probably now have problems !!!

The variability between users leads me to believe it is not the UP software, or unlikely their hardware. It could be other PC/MAC software sending spurious USB signals to the UP port. However my experience of USB makes me think it might be earth currents inducing signals on the USB cable. To mitigate this ensure that the same AC power socket is used for all devices attached to the PC. In the UK dual adjacent sockets always use the same AC phase & earth, I understand in USA, at least, dual adjacent sockets can be off different phases, to share power load. Connecting the PC to one phase and peripherals to the other phase (socket) can lead to high induced earth current spikes on the cables connecting between devices. Best solution is to connect a distribution box (multiple socket outlets to a single wall connector then you know that the AC power and earth are common to all devices attached to the PC including the pc itself. Just checked, my UP power pack AC ground is connected to the DC side ground, outer protective shield and DC power pins. Therefore earth currents can flow between PC ac ground and UP ac ground.

To avoid these currents you could try isolating the ac ground for the UP AC wall plug. (Warning, if you do this, ensure the PC ground is good at the AC plug and PC and that the UP USB is always connected to the PC, as now the USB shield cable forms the protective ground for the UP but no earth currents can circulate)

cheers

Peter

eyUP
Posts: 230
Joined: Thu May 24, 2012 3:23 pm

Re: Printing with USB cable un-plugged

Post by eyUP » Wed Jul 11, 2012 12:48 pm

The variability between users leads me to believe it is not the UP software, or unlikely their hardware. It could be other PC/MAC software sending spurious USB signals to the UP port. However my experience of USB makes me think it might be earth currents inducing signals on the USB cable. To mitigate this ensure that the same AC power socket is used for all devices attached to the PC. In the UK dual adjacent sockets always use the same AC phase & earth, I understand in USA, at least, dual adjacent sockets can be off different phases, to share power load. Connecting the PC to one phase and peripherals to the other phase (socket) can lead to high induced earth current spikes on the cables connecting between devices. Best solution is to connect a distribution box (multiple socket outlets to a single wall connector then you know that the AC power and earth are common to all devices attached to the PC including the pc itself. Just checked, my UP power pack AC ground is connected to the DC side ground, outer protective shield and DC power pins. Therefore earth currents can flow between PC ac ground and UP ac ground.

To avoid these currents you could try isolating the ac ground for the UP AC wall plug. (Warning, if you do this, ensure the PC ground is good at the AC plug and PC and that the UP USB is always connected to the PC, as now the USB shield cable forms the protective ground for the UP but no earth currents can circulate)
This is all good advice and I've seen lots of USB ports (on different devices) getting blown for similar reasons.
An alternative to isolating the UP!'s ground might be to invest in a USB Isolator, eg: "olimex usb isolator"
We had a rogue machine which kept blowing its USB port and have had no problems since fitting the USB isolator.

Billzilla
Posts: 71
Joined: Fri Sep 09, 2011 2:38 am

Re: Printing with USB cable un-plugged

Post by Billzilla » Thu Jul 12, 2012 3:44 am

I had no problem at all, with the 1.15 software but after upgrading to 1.16 I started getting stoppages mid-print.
Bruce from here (wackojacko) told me to unplug the USB cable from the computer and that now seems to be a very reliable method of getting a good print.
It'd be nice to be able to see the layer number that's being printed but it's better to have a successful print rather than a dud.

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