Welcome to the SeeMeCNC Community

Famous for not leaving well enough alone, I wanted to mount the extruder on the endefector. Lots of the problems I was having (I thought/think) stemmed from the bowden tube set up vs the direct drive style.

After seeing the EZStruder released, I decided to mount it on the endefector and just sacrifice some Z height and print speed.

To help carry around the extra weight, I upgraded to the Trick Laser arms (which are working incredibly well).

So I designed a mount in Pro-E, and used the Versa Laser at work to cut them out of 1/4" acrylic. I know its massive, but I just wanted something quick and easy. Here is what it looks like:

[img]http://img.photobucket.com/albums/v737/ ... 4c0d1f.jpg[/img]

[img]http://img.photobucket.com/albums/v737/ ... bddfdc.jpg[/img]

So after getting it physically mounted I wanted to make a few dry runs to see how its going to behave. It did surprisingly well, I noticed the entire printer moving a little bit when it would start doing small infill, but I had it going a little too fast.

I wanted to let it run a while, so I stepped out in the garage. A few minuets later I started smelling something burning, I rushed back inside to see literally 2-3 foot flames coming off the printer! I panicked and grabbed a fire extinguisher and put it out. Here is a picture, I wish I would have thought to get some more, but the top plate is melted to hell as well...

[img]http://img.photobucket.com/albums/v737/ ... fae167.jpg[/img]

I noticed one of the ceramic heaters was glowing red hot (its the one that looks extra crispy in the picture)... I had all the wiring tucked out of the way while I was checking everything out, and when the heater got that hot, that close to the acrylic, it set it on fire.

I still wish I knew why it turned on. I had no thermister hooked up, and when it booted up, it realized that and said that it was in dry mode. I looked again after the fire was out and the Repetier host showed the extruder temp at -20, showed the heater turned off and said it was in dry mode. I rechecked the wiring and both heaters are plugged into the correct spot on the Rambo (same place they've been since I got them ~900 meters of filament ago)

Something went haywire and the Rambo turned that heater on and left it on... Scared the hell out of me!

I thought there was some sort of safety built into the firmware,

where if the heater continued to heat, and the thermistor wasn't sensing a temperature change, it would shut it off after so many minutes.

in your case since the thermistor was out, it should have not allowed it to get that hot.. imma have to look at the firmware again. just for my own curiosity. maybe your thermistor, even though out, was close enough to the heater to sense the heat coming off it.

but i wonder if that safety works in dry run mode now also.

cambo3d wrote:I thought there was some sort of safety built into the firmware,

where if the heater continued to heat, and the thermistor wasn't sensing a temperature change, it would shut it off after so many minutes.

in your case since the thermistor was out, it should have not allowed it to get that hot.. imma have to look at the firmware again. just for my own curiosity

but i wonder if that safety works in dry run mode now.

That was my understanding as well - which is why I was so careless about it.

Please share any findings.

I totally missed this! Do you have a dzf of the design you made for this?

Also, which head are you using with the Ezstruder?

And this is exactly why I dragged that damn heavy data center metal cabinet all the way home from work. It may not stop the fire completely but it will give me some extra time to either put it out before major damage or get out completely.

I am sorry for your loss with the printer.
Hopefully you will be able to recover with a new printer as soon as possible.

Eaglezsoar wrote:I am sorry for your loss with the printer.
Hopefully you will be able to recover with a new printer as soon as possible.

I hope so too! It's been 2 years now

A spammer posted to this thread yesterday, that's what brought it to drunkenmugsy's attention I think.

g.

And that's why I have a couple automatic dry powder extinguishers and a smoke alarm suspended above my printer.

For under the top plate
[img]https://encrypted-tbn0.gstatic.com/imag ... JEA4eJIEgZ[/img]
Above the printer if the first one doesn't work
[img]https://encrypted-tbn1.gstatic.com/imag ... 4zMHEMbe9Q[/img]

Hey Forrie, that is a unique idea but a great one.
Excellent!