Some questions about the Ultimaker2+ (Filament Size, filament types and hotend modifcations)

[xoration 0]

Hello,

I currently want to buy my first 3D printer and I am kinda undecided between the Ultimaker 2+ and a different one. I am not completely unexperience with 3d printing currently all the models I created were printed by a friend of mine. So I already know I want to get a better product.

But anyway that is not what I wanted to ask.

It seems like that most 3D printers nowadays are using a 1,75mm filament. Also a friend told me I shall get a printer with 1,75mm now I've searched around a bit and it seems like the 1,75mm can also be used with the UM2+ without modification is that correct?

Also regarding different filaments, for me it is kinda important to also be able to use different filaments like TPE. I really want to try those rubberized materials. Now I have already searched but sometimes it is hard to be sure this is the latest stage or thread. Can TPE and other stuff be feeded into the UM2+? From my understanding it is not possible, or rather hard and the outcome is unpredictable.

So I have seen some have created modifications for the UM2+ to use a E3D hotend (E3D-v6) with the direct feeder etc. But I am a bit concerned that this modification is getting too heave on the axes. And will lead to problems.

Is this concern unfounded? Maybe someone can help me there. Cause this might be a modification I might be interested in to use other materials like TPE.

Thank you!

[gr5 2,004]

I don't recommend printing 1.75 without some small modifications. 3dsolex sells a nice 1.75mm conversion kit. I've tried it and it works fine. But there's no reason that I know of to go to 1.75mm. All the filament types you might want to print are available in 3mm.

Onto your other question. The thing that makes the Ultimaker somewhat unique is that the feeder and hot end are separated out with the bowden tube in between. This has pros and cons. The main pro is that you get better quality prints because the print head is so light weight that Marlin firmware doesn't slow the head down much on corners so you get equal/even flow from the extruder (a problem if you slow down too much on corners - it over extrudes when it slows down).

But the bowden has cons as well. One of them is that it's difficult to print ninjaflex (as far as I know that's the most flexible material out there). It's like pushing a string through that bowden. But it works. You have to get the "plus" (um2+ or um2ext+) or the UMO or you have to switch out feeders to use the iRoberti feeder (free/open 3d printed feeder for um2 printers). Also you have to print about 5X slower and 20C hotter and you have to add drops of oil to the filament. But it works fine. I've printed many things with ninjaflex. Slightly stiffer flexible materials are even easier to print. TPE is similar to ninjaflex (or maybe the same thing?).

[xoration 0]

Thank you for the reply. The reason I was told to to go to 1,75mm was that it is not breaking as easily as 3mm.

And yes I was talking about ninjaflex. I thought TPE is like the family just like PLA and ninjaflex is the brand. But again what do I know.

You are saying you can print ninjaflex without modifications? That would actually be awesome.

[avogra 68]

I have a UM2 (non plus) where i changed to a ptfe bowden and the bondtech feeder. I can print ninjaflex at 30mm/s easily, but retractions are far from perfect. I didn't want to wait for the new UM2+ feeder. Is it better than the old one with respect to filament guidance?

@gr5, there is more flexible material than ninjaflex. don't remember the brand, but it is some tpe type. from what i have seen, tpe can vary in a large range in hardness. I still have a bit laying at home but didnt find the time to try it.

[gr5 2,004]

You are probably right that ninjaflex is TPE. I don't know. I was *not* able to print ninjaflex on the original black feeder (older UM2 printers) but it prints okay on UMO and on UM2+ or on UMO with iRoberti feeder (a free download from youmagine).

But like I said: 10mm/sec, 240C, oil on filament to oil up the bowden and keep adding one drop every printed meter of filament.

Here's a recent print on a UM2ext plus with pink ninjaflex - made some "feet" for my stress/strain tester:

[Remy 13]

I was able to make the old Ultimaker Flex PLA (not as flexible as NinjaFlex) work with the stock parts, feeder included. Like gr5 said you need to print incredibly slowly, hotter than PLA, and oiling the filament isn't a bad idea. Two other issues come to mind though:

Retractions. Since the filament is so soft, the feeder can chew into it during periods of heavy retractions, causing under extrusion or stoppage of flow altogether. Printing any flex on Ultimaker will require some playing around with retraction settings and feeder tension.

Feeder motor heat creep. The Plus versions won't have this problem because the stepper axle no longer contacts the knurled gear that drives the material, but the older UM2 models didn't have the new feeder and this was a big issue I found while testing. I didn't find a good solution to this other than pointing a big fan at the feeder while printing.