Unloading PLA from BondTech extruder

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jon_bondy
Posts: 104
Joined: Fri Jan 26, 2018 6:24 pm

Unloading PLA from BondTech extruder

Postby jon_bondy » Tue May 15, 2018 9:42 pm

I never had a problem unloading filament with the original Raise3D N2+ dual extruder, but I have to pull the clear plastic tube out of the BondTech each time I unload PLA. It seems that there is a small blob on the end of the filament that is difficult for the BondTech to pass, and I cannot pull hard enough without removing the clear plastic tube.

Do others also have this experience?

EldRick
Posts: 308
Joined: Thu Jun 22, 2017 5:55 am

Re: Unloading PLA from BondTech extruder

Postby EldRick » Wed May 16, 2018 12:32 am

Never Unload the filament on an N2, as there is a fair chance that you will get a jam requiring disassembly sooner or later.

Instead, just heat up the hotend to the temp the filament requires, unhook the feed tube and cut the old filament down to a half-inch or so stub. Then use the manual controls to feed filament, and introduce the new filament to chase the the old filament in as it feeds. Feed around 20cm to clear out the old filament from the hotend until the new filament comes out without mixing the two. This procedure is faster and more reliable than the Unload function.

This removes the chance that heated filament can expand and catch on the entry to the internal PTFE tube , which is what is causing it to be difficult to pull back out. Never back filament out of the printhead on an N2, only feed it in.

Iamkar33m
Posts: 81
Joined: Fri Dec 01, 2017 2:53 pm

Re: Unloading PLA from BondTech extruder

Postby Iamkar33m » Wed May 16, 2018 6:49 am

I out-feed while swapping filament all the time... just make sure to pre-load the filament before unloading, for me that minimizes that "blob" at the end of the unloading filament strand.

- Kareem

mb300sd
Posts: 34
Joined: Fri Mar 30, 2018 7:22 pm

Re: Unloading PLA from BondTech extruder

Postby mb300sd » Thu May 17, 2018 10:26 pm

Iamkar33m wrote:I out-feed while swapping filament all the time... just make sure to pre-load the filament before unloading, for me that minimizes that "blob" at the end of the unloading filament strand.

- Kareem


Ah, I've always wondered what that preload button was for.

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Casale8
Posts: 222
Joined: Fri Oct 20, 2017 5:17 pm
Location: The Real Upstate New York

Re: Unloading PLA from BondTech extruder

Postby Casale8 » Fri May 18, 2018 6:10 pm

I've only used the load button a few times, I just use unload and preload. I've never had a problem unloading and preloading any filament.
Always at 215°C.
-SCC
“One man's "magic" is another man's engineering. "Supernatural" is a null word.” -R.A.Heinlein


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