Changing Filament on UM3

[Bossler 8]

I was curious to understand the operation of the Ultimaker 3 so I did some reading, even in the manual.

 

What I wonder is the procedure of changing filament.

I am used to the following procedure:

- preheat the hot end to the extrusion temperature of the filament used (e.g. 205°C for PLA)

- do some "preloading" = extruding a bit of material 

- unload the filament

 

This procedure has proven to be very effective and to prevent clogging of the nozzle (by remains of the old filament)

 

I seem to not find an easy way to follow this procedure with the UM3?

[kcel 11]

So far on my UM3, I've only used Ultimaker materials.  Which means it can read the RFID tag and it will know what temperature to set the print core for a load or unload.

 

You can then just use the built in facilities to unload the filament and it will handle the heating of the core and either loading or unloading filament.  Loading includes running some filament through so you can visually confirm the color or material has changed.

 

If you using non UM3 materials, I think you just have to tell the printer what class of materials you have loaded into each extruder and then it use that information to heat the print cores on load or unload.

 

[kmanstudios 1,120]

I use a lot of different brands. The basic series remains the same as you mention. You are just stepped through it through the firmware.

 

Loading:

1. Load spool- insert into feeder
2. If it cannot read the NFC chip for any number of reasons:
   1. Manually choose type of material
   2. If manually choosing material not listed, choose material profile chosen in slicer. i.e. If using petg and you chose nylon to set initial range of options, choose nylon when loading
3. Core will heat up to preset temp (Say 200°C for PLA)
4. Then it will feed the filament up the bowden tube and into core
5. Then you get prompted to press the knobby thingy wheel when you see the material coming out. This gives you a chance to purge the previous color.

Make sense?

[Bossler 8]

Thanks for your answers!

 

My experience is that when you first extrude some material and then unload it,
you are way less prone to get remains of the filament left in the nozzle.

 

So I was curious to understand whether there is a step built in into the unload-process in the UM3.

On the Raise3D N2 there is a "preload" function in the Unload-menu that lets you do exactly this.

 

When I started using the N2 I did ignore that button so I encountered a clogged nozzle from time to time.

Following the procedure preload-unload solved that, I never had that problem again.

 

Regarding choosing material to be loaded:

So there has to be a profile for a material to be able to load it, right?

I know one can create new profiles in Cura - are those downloaded to the UM3 then?

[kmanstudios 1,120]

You can either choose generics or have it recognize the nfc chip.

 

I run all my filaments from a polybox to keep them dry and no matter what filament I use, UM or not, I have to choose the generic.

 

So, noperz on the uploading filament profiles to the UM3.

[Brulti 177]

Profiles created in CURA are not uploaded to the printer, but it doesn't matter much since the profiles in CURA takes precedence over what is selected in the printer. As @kmanstudios said, if you do not use UM materials or run them from a drybox like he and I do, you just select one of the generic materials to load it. For example, I'm currently experimenting with wood material, since it's close to PLA, I chose the generic PLA on the printer when loading the wood filament, and it works without problem.

[Bossler 8]

Okay, understood.

 

So you guys do not encounter any problems with clogged nozzles when loading filament a while after unloading?

 

Regarding wood - I have worked with Polymaker Polywood.

Despite heavy stringing and medium adhesion it works quite well and does not damage the nozzle.

The prints do look like made of cardboard.

Edited January 24, 2018 by Bossler

[Brulti 177]

I had no problems so far with clogged nozzles when loading filament a while after unloading.

 

I'm trying the Laywood from CC Products, still tweaking the settings at the moment.

[Bossler 8]

I'd be interested to learn how the Laywood works.

Is it abrasive?

[Brulti 177]

The maker says it's not, and comments I've found online seems to confirm that. However, it can easily clog your printcore if the temperature is too high, as the wood particle burn inside the nozzle. Or if you let it rest for too long in the printcore between prints, then it can burn and clog as well when you start a new print and the nozzle heats up, so it's best to unload it once you're done with it, and do a quick hot pull to make sure to clean it all.

 

It does smell like burnt wood when being printed, and changes color depending on the print temperature, from light brown at 190°C to very dark at 250°C. And you need to print it slow, 40mm/s.

[Bossler 8]

sounds interesting!

Especially the color variations - something you can't do with Polywood.

 

[Brulti 177]

As far as I understand the explanation from the maker, Laywood is made of 40% wood particles, thus why it changes color with the temperatures.

[kmanstudios 1,120]

Overall, the only thing causing clogs are getting too much into the printing and not enough cleaning out of the cores. BB core and PVA type materials really need to be maintained. Mainly because of their moisture sucking abilities and tendency to boil and burn a bit if not kept moving through the core.

 

The AA core can create an issue if you go from a high temp filament (Say PETG or Nylon or worse, PC) down to a low temp material like PLA and others. Just make sure you really, really clean out the cores with hot and cold pulls on a regular basis and you would just fine.

[Bossler 8]

kmanstudios - 

as per my experience (again, not with the UM3 but the R3D N2) extruding a little bit of filament before unloading does prevent clogging issues quite well, too. 

After I started to follow that procedure, I never had to unclog a nozzle again.

 

Might be something that Ultimaker would want to look closer at.

[kcel 11]

1 minute ago, Bossler said:

as per my experience (again, not with the UM3 but the R3D N2) extruding a little bit of filament before unloading does prevent clogging issues quite well, too. 

After I started to follow that procedure, I never had to unclog a nozzle again.

 

There is a Move option for each of the extruders that heats them up and lets you manually extrude or retract.  So you could do a Move operation and extrude a little material, and then trigger the unload process.

[Bossler 8]

Will try that, thank you, kcel.

What is important - you need to unload directly after you did the preload so it's still "fresh and hot".

Like in real life - sometimes the timing is important;-)