Welcome! Log In Create A New Profile

Advanced

auto resume when power loss

Posted by swaroop 
auto resume when power loss
December 17, 2017 07:51AM
hi to all,

I have a 3d printer with marlin rc7 and ramps 1.4. in my area am having regular power cuts like hours. I want "auto resume" option so that if power loss i don't worry about the printed part. please help me in getting out of this.

thanks
swaroop

Edited 1 time(s). Last edit at 12/17/2017 08:07AM by swaroop.
Re: auto resume when power loss
December 17, 2017 11:44AM
The printer has no way of knowing where it was at the time of power failure so it can not know how to restart.
Also after hours the filament and part would be cooled down and restart would require reheating operations.
To compensate for short periods of power loss you need a UPS.
If you run at 12 volts you could run your system off a battery with the mains charging the battery and powering the printer while you print.
That way if power goes off system would run as long a the battery could supply power and would start recharging as soon as the power came back on.
Re: auto resume when power loss
December 17, 2017 12:31PM
Have a 2200 UPS, works my PC computer for up to an hour. They sell an adapter to connect to car batteries or you can make your own, this allows for longer UPS power deliveries times up to several hours.

Brand new Price $900 and up.
You can purchase a used Smart 2200 UPS for about $200, batteries about $132 ($33 each) for original batteries or car batteries $200 ($50 each) for inexpensive batteries.
For a grand total of around $332 for One Smart 2200 UPS. Brand new Price $900 and up.

Or you can Call around, Fast food Restaurants replace them all the time and will give them away so they will not have to mess with them. Then you only need the batteries.

Mine were free. Had to throw one away was completely burned up. The other two needed to drill out the pop rivets to get the swollen batteries out, then used small nuts and bolts to put the frames back together. Took the batteries to the recycling center, ordered batteries from E-Bay out Virginia with free delivery. Batteries was my only cost 4 batteries $132.00 ($33 each). Both work thou only have one with batteries install for now. When I am allowed to will purchase the other four batteries needed to get it working.

Would not tell them that you are going to fix them, just tell the you will recycle them for no cost. (because recycling does include repairing)

Edited 2 time(s). Last edit at 12/17/2017 12:36PM by Roberts_Clif.
Re: auto resume when power loss
December 17, 2017 12:37PM
There is hardware and firmware that has this feature. Wasp printers have had it for some time (and open sourced the firmware changes), Duet electronics and firmware has had it for several months, and now the genuine Prusa i3 MK3 has it too.

These are the ingredients needed to make it work:

1. A means to detect loss of power. Duet electronics has this built in. Prusa's latest i3 uses a separate board attached to the power supply. I don't know what Wasp uses.

2. Sufficient power reserve after power failure has been detected to at least raise the nozzle, retract some filament, and write the current position, feed rate, SD file position, bed compensation etc. to either EEPROM or SD card. Using 24V power helps a lot compared to using 12V power, and the capacitors in a 24V PSU may provide sufficient reserve already. If not, you can add an extra capacitor to the 24V output.

3. A means to turn off the heaters as soon as power failure is detected. Prusa's printer uses an 8-bit controller and he told me that even an interrupt wasn't fast enough, so his controller board does that in hardware. The 32-bit processor on the Duet allows us better control of interrupt priorities, and we find an interrupt is fast enough. If you use an AC mains voltage bed heater then it's less critical because the bed heater doesn't drain the power reserve.

So it's possible, and it is supported as standard in RepRapFirmware, and in at least one fork (Prusa's) of Marlin plus whatever firmware Wasp is using.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: auto resume when power loss
December 17, 2017 11:46PM
but... depending on your build surface and type of plastic the plastic may separate from the build platform when it cools. This is not recoverable
Re: auto resume when power loss
December 18, 2017 04:56AM
Quote
Dust
but... depending on your build surface and type of plastic the plastic may separate from the build platform when it cools. This is not recoverable

Yes, if you use a heated bed and the power is off for more than a few minutes, that's a problem. Also it helps if you can home all 3 axes when there is already a print on the bed.

Edited 1 time(s). Last edit at 12/18/2017 04:57AM by dc42.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: auto resume when power loss
December 18, 2017 11:17PM
For Ramps, we have used Arduino Uno to detect the loss of power. When the power is not there, it will send the signal to the RAMPS and it will pause immediately. But, here we are having UPS back up. So, the printer will go to Pause mode, heaters will be switched off.

When the power comes, Uno will send the signal to RAMPS, it will resume the printer. (Heaters will be switched on and it will go to the printing location).

In the above case, the main board is given back up power, so it is like a Pause-Resume condition, but done automatically when the power is gone.

"2. Sufficient power reserve after power failure has been detected to at least raise the nozzle, retract some filament, and write the current position, feed rate, SD file position, bed compensation etc. to either EEPROM or SD card. Using 24V power helps a lot compared to using 12V power, and the capacitors in a 24V PSU may provide sufficient reserve already. If not, you can add an extra capacitor to the 24V output."

How to read the current position and how it can be saved to the SD Card? For Marlin, some people are suggesting to write in EEPROM, again it is a risky thing that writing more times in EEPROM will give adverse effects.
Sorry, only registered users may post in this forum.

Click here to login