Hotend smoking on First Rostock max v2 print

[RamonIn3D]

Hello everyone
I have just finished Assembling and calibrating the Printer, and now I'm supposed to print the PEEK fan shroud. Everything went well until the hotend reached a temperature of about 220°C, at that Point, White smoke started coming out from somewhere around the top of the hotend, I couldn't see where exactly it was coming from, since I immediately shut off the power to the Printer. The Filament wasn't near the Hotend yet (I forgot to do that...). I know that it might smoke a Little when you heat up a hotend for the first time, but there was never this amount of smoke on my other printers. I don't really know how to describe the amount... but it was like a continuous stream of something that looked like a 1.5cm wide, white band. I looked at the wiring from the hotend, but couldn't see anything different from when it is cold. All the wires that come close to the hotend are wrapped in kapton, and so is the hotend itself, the only exposed things are the two PTFE tubes from the Thermistor.

So... Is this supposed to happen and I'm just worrying about nothing and should just start printing?

Oh and I couldn't find the exact Silicone that was specified in the instructions. But the one I used instead is supposed to be used up to 350°C, maybe this could have something to do with it? I don't know.

Ramon

[KAS]

What is the silicone you used?

[RamonIn3D]

I used this one, just the 300°C version, which I couldn't find on the website: http://www.coltogum.ch/produkte/dichten/hitzefest-250c/ I said I need to fix thermistors and heaters into a heating block, and described the application in 3D printers, and they recommended me that one.

The coltogum website is in German( or French), but I also found this in English: http://www.amazon.co.uk/Coltogum-163198 ... B0052WSCNI which seems to be the same thing.

[Tincho85]

Just a personal suggestion, remove those resistors, get a 40w heater cartridge, tap a hole and done. It's so much cleaner.
Ther first time I put together my Rostock Max the hotend did the exact same thing... the only difference is that my thermistor was damaged and the peek insulator got melted

[Tincho85]

like this one:
[img]https://www.doodaddoes.com/wp-content/u ... HotEnd.jpg[/img]
https://www.youtube.com/watch?v=Fdb3nyu29ko

[KAS]

I used this one, just the 300°C version, which I couldn't find on the website: http://www.coltogum.ch/produkte/dichten/hitzefest-250c/ I said I need to fix thermistors and heaters into a heating block, and described the application in 3D printers, and they recommended me that one.

The coltogum website is in German( or French), but I also found this in English: http://www.amazon.co.uk/Coltogum-163198 ... B0052WSCNI which seems to be the same thing.

I see, it's possible that type of adhesive out-gases a bit more then we're use to seeing with the copper stuff. I would place the heater at 150c and let it sit for a while. You just want to make sure the thermistor is reading the temperature correctly and not running away over-heating the adhesive.



edit spelling :/

[RamonIn3D]

Okay, I'll let it sit at 150°C Tomorrow morning and test it again in the afternoon. If it doesn't help I might just start printing and see what happens? I have an E3D v6 as a backup in case i break the stock hotend so i could maybe print a mount in Colorfabb XT on my other printer.

And if I break any of the Electronic stuff on the Hotend, I'll try to do that Heater cartridge mod, since it really is a lot cleaner.

[geneb]

Don't let it sit there and cook all day! Run it at 150 for like 10 minutes and then start bumping the temp up.

g.

[RamonIn3D]

Oh I thought I needed to leave it hot pretty long, since I already left it at 190°C for the calibration process, should I let it heat up to 150°C, wait 10 mins and then get it up to 228°C and start printing? Even if it would be smoking?

[geneb]

It should stop smoking. You may want to get a thermocouple to verify the temperature that the thermistor is reporting is accurate.

g.

[KAS]

My apologies, I didn't clarify that better. I'd just start off easy from 150ish and start turning up the heat little by little. Once it starts smoking, don't increase the temp until the smoke clears then continue until your desired print temp. Worst case your thermistor is under reading the temp by 40c and you melt the peek section. :O

I'd say you're using adhesive that nobody else has tried. This is an experiment for everyone!

[Tincho85]

Yes, he could be cooking the silicone. That's what I'm afraid of, if the peek melts it's a pain... to remove.

[RamonIn3D]

Okay, I tried heating it up in steps of about 10-20 °C every 5-10 minutes until I got up to 228°C, which seemed to have solved the smoke issue. I could still see some smoke, but it was nowhere near as much smoke as before.

I Poked the PEEK (with a screwdriver) to see if it has gone soft, but it's still hard.

I tried melting some PLA on the nozzle at about 160°C which did not work.

I extruded some ABS at 228°C which made it come out of the nozzle with a bit of resistance, so these things lead me to believe that the thermistor is reading the temperature correctly.

I also saw that when I push some filament into the Bowden tube, the smoke comes out of the nozzle when I push, so it might be some residue of some sort inside the hotend that made the smoke?

So now that I don't see any smoke ( or smell anything special ) I'm going to start the first print.

Also another observation, the hotend overshoots the target temperature always at least 5-10°C

Thanks for the help so far!

UPDATE! It works! it even sticks to the bed, as far as I can tell!

[RamonIn3D]

I thank all of you again for helping me with this, it worked and the first print doesn't look too bad for a first print!

[geneb]

Excellent job!

Go forth my son and 3D PRINT ALL THE THINGS!



g.