Special filaments in the U3.

[Clancey 0]

Hi folks.

Before I go ahead and royally bugger up a load of expensive print cores, which if the specialist materials can I use with the U3 cores, .4 and .8. I'm assuming I'd be better off using the .8.

And should I use the A or the B core for such things?

And for that matter, if I can load the print head with 2x AA heads, why is there a BB, what does the BB do that the AA doesn't, or vice-verca?

Many thanks.

[SandervG 1,521]

Hi @Clancey,

Thank you for your message!

I'm not sure if I understand your questions correctly regarding specialist materials. Could you explain?

General rule of thumb is that abrasive materials are not recommended, as they will wear down your nozzle. These are materials like carbon fiber, bronze / brass-fill and glow in the dark. If you want to remove any doubt, you should be in the safe zone with Ultimaker filaments for sure.

You can go for .8 print core if you want to save time and print fast. Because the nozzle is bigger, it can extrude more plastic, thus it can print thicker layers, and your print will be done faster.

This also means that generally, what people consider as quality (super smooth spheres) the quality is 'lower'. I mean the layers are thicker so it is easier to feel these steps with your finger nail. Detail in x and y is also less for the same reason, the nozzle is bigger. Like trying to make a detailed drawing with an Edding 800 marker.

Regarding the different print cores, you can choose different types of support constructions, and different support materials. One being support material which is the same material as your build, so a PP print has PP support and a Nylon print would have Nylon supports. You would remove them with pliers and potentially sand down your print to remove some final marks.

For this, you only need 1 print core. Everything will be built with an AA core.

With the Ultimaker 3 you can also print with 2 print cores (AA & BB). We have a special support material called PVA. PVA can be dissolved in water. This material is meant to be printed with the BB print core. This means your surfaces will be cleaner and you can print more complex parts since you no longer have to be able to reach everything with pliers.

Why should PVA be printed in the BB print core? PVA behaves differently when molten, and has a higher tendency to burn than other filaments. Therefore, the internal geometry of print core BB is different. It avoids the burning risk. This internal geometry makes it less fitting to use it for the build materials like PP, Nylon, PLA etc.

That is why there are 2 print cores, they are tailored to work best with different type of materials.

Let me know if you have any further questions!

Edited October 16, 2017 by Guest

[Clancey 0]

Thanks, that pretty much explains everything. BB's are built differently and specifically for the PVA and other support materials which I've used to great effect. Cool.

And glow in the dark is abrasive? I've just read this, literally 5 minutes from setting of a 4 hours glow material print! Oh well.

How abrasive? What guidelines are there for these 'filled' materials? I'm not so interested (at the moment) with the metal fills, but I do want to start with the wood. I'm guessing you advise using the .8 cores. Are you also suggesting that I should be using a cheaper less quality machine where I'm going to destroy nozzles that cost a few quid instead of cores that cost £90?

I have ordered a CR-10 for just this reason, or at least 'banging out' stuff where the quality isn't as demanding as the work intended for the Ulti.

And on brands, with pretty much default settings, and without forensic testing, I've found the RigidInk PLA materials the most problem free. Apart from your Nylon which I simply cannot make go wrong, it's superb.

But I did buy the Ulti with the intention of making many different things in many different materials, so if you have a list of those materials you feel unsuitable for this printer please let me (us new folk) know so I don't go buggering up expensive hardware unnecessarily.

Many thanks.

[SandervG 1,521]

Hi @Clancey,

thank you for your reply.

FYI, I made a few grammar-changes to my original reply, after reading it again I felt some things could be explained better.

How abrasive glow in the dark is, is hard to tell. I have no doubt this can be quantified however I've never seen any numbers about this, or other materials. Perhaps someone else from the community has any numbers on this?

Woodfill is not considered to be abrasive, because the wood fibers are not stronger than brass. In the case of bronze and copper this is the case. I would indeed recommend .8 print core, because the wood fibers make it more likely to burn as well, so you want them to pass through the nozzle fast.

Maybe it would also work in a BB print core, but I've never tested this. I can imagine you would have some more 'oozing', and less burning (clogs).

I think the most 'problematic' would be abrasive materials, since they acitvely wear down your nozzle. Until a print core will be released (not sure if this is on the planning, but the point remains valid), and you don't want to consume your regular AA and BB print core's you could consider getting a third party 'Hardcore'. They look like print cores but have swappable nozzles.

Abrasive materials are: 'metal'-fills, glow in the dark, carbon fiber filaments. Did I miss anything?

[geert_2 558]

Abrasive materials are: 'metal'-fills, glow in the dark, carbon fiber filaments. Did I miss anything?

 

You missed stone-fills.

I found that plain white (colorFabb) is also slightly abrasive. On one of my printers I only printed colors (mainly orange, red, natural, blue, pearl, from both Ultimaker and colorFabb), and on one I printed almost only white. After about 800 hours of printing on both, the "white" nozzle is clearly worn: the flat area at the bottom of the nozzle is larger than that of the "color" nozzle, which is still fairly original. The inner diameter of both nozzles has increased from 0.39mm to about 0.41 or 0.42mm. I haven't counted the amount of white spools I printed: maybe 6?

I guess this is due to the filler particles used in the white, to get a thick opaque color. But I have no idea which particles they use: talcum? Titanium dioxide? Other?

So, nothing to worry about if you print only a few spools of white. But if you print white for 24h/day, you should keep an eye on this.