Extruder mount failed

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Mach
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Joined: Sun Nov 29, 2015 1:05 am

Extruder mount failed

Post by Mach » Tue Apr 19, 2016 3:41 am

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How hot should the extruder motor (X-axis) be? Mine was 130F this evening. I've been printing alot of ABS lately in an Ikea enclosure that is ventilated via a 140 mm blowhole in the side and top. I'm printing 8-9 hours at a time and switching filament toward the end of the print. I noticed that the extruder mount flexed last night when changing filament. Well it failed in spectacular fashion this evening. I'm assuming it was from extruding 50mm of filament in one go or the heat - or both.

The mount is delaminating and crumbling. I've already got a metal motor mount to install but I'd like to understand what happened.

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insta
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Re: Extruder mount failed

Post by insta » Tue Apr 19, 2016 6:06 pm

I wonder if that's solvent-attack from the gearbox lubricant? What an odd failure.
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Mach
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Joined: Sun Nov 29, 2015 1:05 am

Re: Extruder mount failed

Post by Mach » Tue Apr 19, 2016 6:45 pm

Not sure, what are these printed with? ABS? I've used lithium grease on the rails. The last 8-10 bottles that I'm printing, I'm wiping the neck of the bottle with a small amount of acetone but its a very small amount. Could acetone vapor have caused embrittlement in the heated environment?

To be clear, I'm dipping my gloved finger in acetone and wiping across the x-sectional top of the 1st half of these print when changing filament to promote adhesion for the next layer. These bottles are hollow so the cross section is very small.

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thunderbt3
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Re: Extruder mount failed

Post by thunderbt3 » Tue Apr 19, 2016 7:58 pm

Yup, the printer parts are printed in ABS.

Mach
Posts: 63
Joined: Sun Nov 29, 2015 1:05 am

Re: Extruder mount failed

Post by Mach » Tue Apr 19, 2016 8:40 pm

Thanks for the confirmation. I'm surprised that such a small amount would do this but live and learn. I'll fix the motor mount and start printing replacements for the other parts. Any suggestions for alternate filament than abs? I've seen ePC recommended but I'm not crazy about the color. I have a couple roles of colorfabb XT and ngen that I could use.

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: Extruder mount failed

Post by jsc » Tue Apr 19, 2016 8:57 pm

Um, PLA? The easy mode filament for 3D printing. I don't think your bottles need a lot of heat or bend resistance.

Nice prints, btw.

Mach
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Joined: Sun Nov 29, 2015 1:05 am

Re: Extruder mount failed

Post by Mach » Tue Apr 19, 2016 11:14 pm

Thanks. I started out printing them in PLA but then discovered acetone vapor smoothing with ABS. It really give them a glass like finish. I'm still surprised the mount failed due to acetone vapors. Folks who are using an acetone slurry on their glass are likely using more than I was and would see similar failures.

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Jules
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Re: Extruder mount failed

Post by Jules » Tue Apr 19, 2016 11:22 pm

Perhaps you could do the acetone vaporing in a different container? (Big Bell jar in the sun.) Instead of inside the enclosure.

Mach
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Joined: Sun Nov 29, 2015 1:05 am

Re: Extruder mount failed

Post by Mach » Wed Apr 20, 2016 12:29 am

Thanks Jules and sorry for the confusion. I am not doing the acetone vapor smoothing in the printer enclosure. I'm smoothing in a paint can outside the enclosure.

When I stop the print to change filament, I would coat the top edge of the bottle with a little acetone to make it sticky. In the pic below, it would be only the x-section of the bottle where the print head contacts. I'm also printing on PEI with hairspray. I don't think the hairspray is causing the problem.

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Jules
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Re: Extruder mount failed

Post by Jules » Wed Apr 20, 2016 1:12 am

Whew! That's good - i thought you were using the HBP to flash the acetone! (Planned to keep an eye out for the boom!) :lol:

Now i'm wondering what caused the mount to crumble?

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