Does the TAZ have any over heating safety measures?

A forum dedicated to the stock LulzBot TAZ 3D Printer
wmgeorge64
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Re: Does the TAZ have any over heating safety measures?

Post by wmgeorge64 » Fri Jan 08, 2016 12:05 pm

It would be an interesting feature to have working and I wonder why its not done?? :(

I was wondering why it was not implemented, its kind of a common sense thing.

I have a Raspberry Pi and the webcam just have not got it done yet. So many things to do, even if your retired :) and still learning .

ttabbal Can you use your Pi setup to manually move the printer axis and prime the extruder like I do now with my PC?
ULS Laser . Retired master Electrician in Iowa USA Lots of Hobbies

kmanley57
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Re: Does the TAZ have any over heating safety measures?

Post by kmanley57 » Fri Jan 08, 2016 12:10 pm

I am not him, but to answer. Yes I do it quite often with Octoprint. 8-)
I will express my CRAZY ideas at any time! So you have been warned. None of my opinions are Lulzbots and can be wrong at any second.

ttabbal
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Re: Does the TAZ have any over heating safety measures?

Post by ttabbal » Fri Jan 08, 2016 12:12 pm

Thanks for the tip! I posted over there, hopefully we can get something going for the Mini.

And yes, there are controls in Octoprint for the movement and temperature settings. In some ways, they aren't as nice as Cura/Simplify3D, but they get the job done.

wmgeorge64
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Re: Does the TAZ have any over heating safety measures?

Post by wmgeorge64 » Fri Jan 08, 2016 3:56 pm

ttabbal wrote:Thanks for the tip! I posted over there, hopefully we can get something going for the Mini.

And yes, there are controls in Octoprint for the movement and temperature settings. In some ways, they aren't as nice as Cura/Simplify3D, but they get the job done.
Well my plan is to use Simplify 3D for the slicer and Save the gcode to a SD. So I am assuming the Octoprint runs on the SBPi and the screen you have connected to it, allows you to control the machine interface. I'm sure I have missed something but trying to juggle a few projects around to get the time for this. Thanks again for the postings.
ULS Laser . Retired master Electrician in Iowa USA Lots of Hobbies

tmorris9
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Re: Does the TAZ have any over heating safety measures?

Post by tmorris9 » Fri Jan 08, 2016 4:39 pm

The worst case is when the board fails and puts constant power to the hotend. No configurations will help this and it often ends in fire. Over on the RepRap forums there is a thread dedicated to safety and you can read some of the horrors that have gone wrong including fire that almost burned down the owners houses.

It can happen but is still unlikely. Best thing to do is prepare for a worst case scenario just in case. Always have a fire extinguisher handy of ample size (not one of those kitchen ones but at least a 5lb one). Of course one of the big no-no's that everybody does is that you should not leave your printer unattended while printing. Keep flammables away from it as best you can (curtains and such).

Some people are going to the extreme of hanging self activating fire extinguishers above the printer or having a second temperature sensor on the hotend with a power cutoff relay so if it goes above say 300c it cuts the AC power. A fire proof (or resistant) enclosure is another good idea.

You really don't need to be afraid of your printer, just aware of what may happen and take the measures that make you feel best.

kcchen_00
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Re: Does the TAZ have any over heating safety measures?

Post by kcchen_00 » Fri Jan 08, 2016 5:11 pm

I've gone the route of home automation to implement safeguards with the printer. A motion sensor under the bed senses movement, power to the printer is shutoff after a 20min delay when no motion is sensed. WeMo has a quick and dirty motion sensor & plug combo... at least last time I checked.

I use a Smartthings Hub with Zigbee sensors and plug. It allows for integration of a First Alert Smoke/Fire detector... so if smoke/fire is detected, the plug shuts off. The printer safe guard is in addition to the home monitoring and alerting through the home automation.

The solution works well. Utilizing the remote printing through Octoprint, I've only baby sat two or three prints in the time I've owned my TAZ5.

ttabbal
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Re: Does the TAZ have any over heating safety measures?

Post by ttabbal » Fri Jan 08, 2016 7:06 pm

wmgeorge64 wrote:
ttabbal wrote:Thanks for the tip! I posted over there, hopefully we can get something going for the Mini.

And yes, there are controls in Octoprint for the movement and temperature settings. In some ways, they aren't as nice as Cura/Simplify3D, but they get the job done.
Well my plan is to use Simplify 3D for the slicer and Save the gcode to a SD. So I am assuming the Octoprint runs on the SBPi and the screen you have connected to it, allows you to control the machine interface. I'm sure I have missed something but trying to juggle a few projects around to get the time for this. Thanks again for the postings.
I don't have a screen connected to the pi. It's possible to do, but I have my smartphone with me most of the time and can control it over the network that way. I also have computers in the room.

So my workflow is to slice and save the gcode on the computer using Simplify3D, or Cura. I have a browser open to the Octoprint page. Bring that up, then the file browser already open to the gcode directory. Drag the gcode to the left side of the webpage and it automatically uploads to octoprint which saves it on the SD card that's already in the pi. Then click print and it goes.

If you drop the file on the right side, it will save to the printer's SD card. At least that's what it says, my Mini doesn't have a slot so I don't know. But since I have octoprint running already, I figure it doesn't hurt anything to let it feed the gcode to the printer.

It also has the Webcam feed which is handy for checking on the print in progress. I use the camera module the pi people make and a printed mount. I added some LED lighting so I can turn the room lights off and still see the image. That same page has controls for the X/Y/Z steppers and extruder. The temperature gets its own tab.

wmgeorge64
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Re: Does the TAZ have any over heating safety measures?

Post by wmgeorge64 » Sat Jan 09, 2016 10:50 am

Excellent posts on using the Raspberry Pi and fire safety.

So did most of the fires start because of a software glitch and extruder heater or did the fire start elsewhere on the machine?

ttabbal Thanks for the detailed write up for printing remotely.
ULS Laser . Retired master Electrician in Iowa USA Lots of Hobbies

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piercet
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Re: Does the TAZ have any over heating safety measures?

Post by piercet » Sat Jan 09, 2016 12:33 pm

The most common 3d printer fire causes are:
1. the heater core fell out of the heater block, the thermistor tried to heat up the block and caused the heater core to basically melt down and combust.
2. The nozzle dug into the part it was printing, got it wrapped up around the hot end, and then eventually the plastic combusts
3. The controller board fails in a manner that causes power feed to the hot end constantly with no imput from the thermistor, causing it to melt down in the nozzle and combust. RAMPS and RAMBO boards don't seem to be as prone to that.
4. The power supply itself catches on fire due to being a cheap knockoff, or wired incorrectly

bam
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Re: Does the TAZ have any over heating safety measures?

Post by bam » Mon Jan 11, 2016 2:44 pm

Sebastian's exactly right. The feature isn't disabled on the TAZ, the thermal runaway wasn't even implemented until it came out around the time we were working on the Mini and TAZ 5. We implemented it on the Mini but had to disable it for release as it had been throwing false positives frequently.

Anyway, we've continued to work on the feature and have a pretty stable setup in the TAZ 6 development firmware: https://code.alephobjects.com/diffusion ... /Mangrove/. There are also some other neat features we're testing like the ability to resume printing after shutting off the printer and micron level control of the first layer height through the LCD :) .

On a side note, we've always put a lot of effort into making our hotends as safe as possible. Neither the Budaschnozzle or the AO-Hexagon rely on tape, rubber or glue to secure the heater and thermistor in place. The thru-hole design of the budaschnozzle and the retention plate on the side of the AO-Hexagon make it so that if the thermistor or HC are pulled out of the hotend they'll break at the retention plate and cause printer shutdown. In fact out of the millions of print hours in our cluster and the thousands of Lulzbots out there in the world, thermal runaway has never happened on one of our machines in stock configuration. The only thermal runaway we've heard of was caused by a non-stock hotend having its thermistor pulled out of the kapton tape holding it in place. Moral of the story: We try to make our products as safe as possible, but please be extremely careful if you decide to modify or replace the hotend.

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