UM3 hot and cold pull - no atomic method

[yvichrome 2]

For the Ultimkaer 2 / 2+ atomic method for cleaning the nozzle is recommended - for the UM3 hot and cold pull - are recommended - the atomic method explicit not.

https://ultimaker.com/en/resources/19510-how-to-apply-atomic-method

Why?

What, if I want to clean a nozzle from ABS - with the temperatures recommend for hot and cold pull in the maintenance menu / manual, I won't melt ABS good ..

https://ultimaker.com/en/resources/23132-clogged-print-core

Thanks in advance ..

[kmanstudios 1,120]

I have seen nothing to say that the atomic-pull is not recommended for the UM3 series.

I have had to do it several times. Just made sure it is in a corner or you can bend the x-y rods.

Edit:

Here is a link to a post I made about having to do this.

I have had to do this on the AA and BB cores. Usually if I go from a hot temp material, say PC or Nylon, without cleaning, the lower temp materials (Say PLA) can get gunked up and require a nice thorough cleaning.

PVA is its own special hell sometimes......

Woiked for me. Do you have a link to a place saying to not do the Atomic-Pull on the UM3?

Edited July 3, 2017 by Guest

[IRobertI 520]

"Cold pull" and "Atomic" are interchangeable terms. It's the same thing really.

[yvichrome 2]

Woiked for me. Do you have a link to a place saying to not do the Atomic-Pull on the UM3?

yes ... - the link I gave above https://ultimaker.com/...-apply-atomic-method says: ...the Atomic Method applied to the Ultimaker 2+, but this method can be used on all Ultimaker 3D printers, except the Ultimaker 3 (Extended). If you have an Ultimaker 3 or Ultimaker 3 Extended, take a look at the guide on ... - thats why I ask.

[yvichrome 2]

"Cold pull" and "Atomic" are interchangeable terms. It's the same thing really.

I thought so too, but as afr as I understood, the recommended "Pull-Temperatures" are different. 90° vs 70° (for PLA).

[kmanstudios 1,120]

Woiked for me. Do you have a link to a place saying to not do the Atomic-Pull on the UM3?

yes ... - the link I gave above https://ultimaker.com/...-apply-atomic-method says: ...the Atomic Method applied to the Ultimaker 2+, but this method can be used on all Ultimaker 3D printers, except the Ultimaker 3 (Extended). If you have an Ultimaker 3 or Ultimaker 3 Extended, take a look at the guide on ... - thats why I ask.

If you follow the link in that article it then describes doing a cold pull also referred to as an atomic pull.

I think what they may be referring to are the individual steps being different.

[Labern 774]

The temps may also be different as the hotends have different heat zones and are made quite differently.

[geert_2 557]

You need to adjust the temperature to the material you are trying to remove and to the material that you use for pushing/pulling.

I usually do the cold-pull / atomic-method a little bit different:

- place nozzle in front corner,

- remove bowden tube and filament,

- heat the nozzle, insert a piece of filament and push through some material by hand,

- dial down temp to zero,

- gently push a few more seconds,

- do a small manual retract of a few mm (this prevents a big blob from forming in worn-out couplers on the UM2, which would make pulling it out impossible or very difficult),

- hold the filament there until cool,

- use compressed air to cool the nozzle faster to room temp (from a compressor only! Never use spray cans: they may contain explosive gasses, and you don't want that on hot nozzles!!!),

- let it sit at room temp a bit, so the inner part of the filament also gets time to cool well,

- gently wiggle and turn the filament: this tends to loose debris that is stuck to the nozzle's inner walls,

- heat the nozzle to 70°C (for PLA) or 120°C (for nylon), or whatever works for your material,

- gently keep wiggling and turning the filament, and gently pull until it releases.

So this method is much more gentle than the usual method. The big advantage is that this gives no risk of damaging the rods, or of displacing the coupler and nozzle, contrary to the brutal pulling of the classic atomic method. Also, cooling down deeper and longer makes debris come loose easier, and it solidifies the inner core of the filament: so when heating up again, only the outer layer will be soft, while the inner is still hard: this reduces the risk of the filament breaking half way.

Sometimes I also poke through the nozzle from below with a needle (very gently, because steel needles are harder than brass nozzles, and it could do damage); or I wipe debris on the inside of the nozzle with a brass M3 screw thread (must be brass, no steel: this would be too hard).

This method does not work with my modified ABS+ (too weak: breaks), and does not work well with PET (sticks too much). Then I use PLA or nylon instead to clear the remains of these materials.

This works excellent on the UM2, better than the traditional atomic pull, but I can not say if it would be suitable for the UM3? Especially, can the UM3 nozzles withstand the wiggling and turning action to loose debris?