Cold pull question - automatic or manual?  

Re: Cold pull question - automatic or manual?

The motor by itself will not be able to cold pull the filament. In fact, that should be prevented within firmware - the extruder motor will not run if the nozzle is less than 130 degrees.

You need to release the tension on the pulley and pull with pliers (you can turn off motors first, which will mean you may not need to release the tension).

Peter

Re: Cold pull question - automatic or manual?

The LCD has a setting "Disable Steppers" so I selected it. However, when I view the setting again it still says "Disable steppers". Shouldn't it say "Enable steppers"? Anyway, I used pliers and pulled the filament out forcefully but nothing else came out other than the filament itself. I tried once at 95 degrees and once at 90 degrees. I then used the supplied needle and inserted into nozzle at 215 degrees as explained in the manual. Now printing again to see.

The motor by itself will not be able to cold pull the filament. In fact, that should be prevented within firmware - the extruder motor will not run if the nozzle is less than 130 degrees.

You need to release the tension on the pulley and pull with pliers (you can turn off motors first, which will mean you may not need to release the tension).

Peter

Re: Cold pull question - automatic or manual?

What kinda filament are you using to Cold pull? While it can be done with PLA, its not as effective as other materials.

I'd recommend getting a small roll of nylon filament(nylon 618), that seems to work the best for Cold pulls. Its pull temprature of 140 will allow the PLA to soften up a bit and adhere to the Nylon, and the nylon is strong enough wont break during the pull.

example of successive pulls done with nylon (not my picture)

Re: Cold pull question - automatic or manual?

Interesting, I just placed an order for esun cleaning filament, not sure if it's nylon but should be similar. I also noticed text printing of small letters isn't as accurate as before so I think I may have damaged the nozzle slightly by swirling the needle through the brass nozzle. Either that or the esun pla+ filament I'm using slowly degraded the nozzle even though it's pla and shouldn't be damaging it. I ordered replacement nozzles to compare. I never replaced one before, haven't even needed to open the extruder up at all.

What kinda filament are you using to Cold pull? While it can be done with PLA, its not as effective as other materials.

I'd recommend getting a small roll of nylon filament(nylon 618), that seems to work the best for Cold pulls. Its pull temprature of 140 will allow the PLA to soften up a bit and adhere to the Nylon, and the nylon is strong enough wont break during the pull.

example of successive pulls done with nylon (not my picture)

Re: Cold pull question - automatic or manual?

Joel Telling of 3D Printing Nerd on Youtube has a video on how to replace a nozzle. He talks about how to replace a brass with a hardened or plated nozzle. I can't remember which. Brass nozzles can degrade over time because of dust and dirt coming into the hotend via the filament.

And eSun Cleaning filament is not Nylon. Do not attempt to use it for cold pulls. The purpose of the cleaning filament (I have some too) is to push the dirt and old filament through the nozzle. I have yet to encounter a situation where the nozzle is so clogged that the cleaning filament doesn't work. That said, I also have a plated nozzle from Micro Swiss.

Re: Cold pull question - automatic or manual?

Joel Telling of 3D Printing Nerd on Youtube has a video on how to replace a nozzle. He talks about how to replace a brass with a hardened or plated nozzle. I can't remember which. Brass nozzles can degrade over time because of dust and dirt coming into the hotend via the filament.

Considering I don't use an enclosure I can see how the dust wouldn't help. And I did order a hardened nozzle so look forward to replacing that once delivered.

And eSun Cleaning filament is not Nylon. Do not attempt to use it for cold pulls. The purpose of the cleaning filament (I have some too) is to push the dirt and old filament through the nozzle. I have yet to encounter a situation where the nozzle is so clogged that the cleaning filament doesn't work. That said, I also have a plated nozzle from Micro Swiss.
The filament says 'natural' with print temp 160 - 280. I will just load it as I do with PLA and see what happens. Thanks.

Re: Cold pull question - automatic or manual?

The Atomic method from Ultimaker does work. However, it is often not needed. And can fail. Try 5 deg above filament temp first and the extruder stepper backing out the filament. Then try the Atomic method. Then do as I do remove the nozzle, and replace with one of my many E3D spares and unclog the nozzle later in a gas flame. I keep many spare nozzles across all my different 3D printers. Only once did I have a clog go back into the heatblock on a genuine E3D hotend. The PTFE tube had shifted. Yes the all genuine metal E3D hotends still have a PTFE tube insert.

Re: Cold pull question - automatic or manual?

I've been reading about the atomic method to clean the nozzle and understand that the nozzle temperature should be set 90 degrees. I I already have filament loaded, can I set the temp to 90 and select "unload filament" on the LCD and pull at the same time? Or is there no need to choose that option and should I just pull it out manually?

I've found the filament in this kit to be useful. It is nylon.

http://www.makergeeks.com/noclkit.html

Re: Cold pull question - automatic or manual?

Try 5 deg above filament temp first and the extruder stepper backing out the filament.

By "extruder stepper backing out the filament", is that the same as unloading the filament? I have a feeling the brass nozzle is slightly wacked so look forward to removing the nozzle to compare once I get the replacement nozzles from England.

Re: Cold pull question - automatic or manual?

I've been reading about the atomic method to clean the nozzle and understand that the nozzle temperature should be set 90 degrees. I I already have filament loaded, can I set the temp to 90 and select "unload filament" on the LCD and pull at the same time? Or is there no need to choose that option and should I just pull it out manually?

I've found the filament in this kit to be useful. It is nylon.

http://www.makergeeks.com/noclkit.html

OK, I tried the esun cleaner filament and see the difference. It's hard but it does go through the nozzle with a slight push. Didn't help really but at least I tried. I'll try to order this nylon one to help with cold pulls thanks.

Re: Cold pull question - automatic or manual?

@prusayo Yes backing out can be just "unloading the filament". Or choose move axis in the settings, and select the extruder, and set the movement mm and then use the thumbwheel to move the filament, you can try forward and then backwards via the thumbwheel.