Problems with PLA Flex

[irajek 0]

Hi,

had my UM2 for a while now and wanted to try my luck with PLA Flex,

but every time I insert it into the printer, after a few centimeters, the filament slips from the bolt and I can't do anything about it.

Am I missing something essential?

Hope the information I gave is sufficient.

Best

 

[DidierKlein 729]

Hi and welcome to the forum,

Flex PLA is tricky to print with bowden printers but it's possible.

What is the brand of filament you're trying to print?

A usefull tip is to change the feeder, i print with the https://www.youmagine.com/designs/alternative-um2-feeder-version-two which works great with flexible filaments.

Some also add a bit of oil to make it easier to feed (this is particularly usefull with Ninja Flex i believe)

 

[irajek 0]

Thanks for the welcome,

I'm using the original PLA Flex that I ordered with my UM.

You mean oil in the tube?

Unfortunately I didn't get that far yet, the filament always slips from the feeding bolt.

I'll have a look at the alternative feeder.

 

[DidierKlein 729]

Ok so it's Ultimaker Flex PLA, i printed with that one but you need to change the feeder or add some sort of guide in the existing feeder to make it work.

Your best bet is with an alternative feeder, (there a lots of them on youmagine i just linked to my favourite).

There's a guide that you snap on to avoid the filament from going anywhere else than in the bowden (it's so soft that it can go anywhere else if there's a bit of pressure).

Oil is not necessary with that one

 

[pm_dude 27]

I get really good quality prints with FlexPLA and NinjaFlex without oil. You just need to figure out the good tension on the feeder (I use Roberts feeder with the filament guide). Even NinjaFlex doesn't slip now.

 

 

The thing with Flex PLA and Ninja Flex is that tall prints eventually become too flexible and move during the print...

 

[irajek 0]

Hey!

printed the feeder yesterday, installed it today.

Works like a charm, or at least now the filament doesn't slip anymore.

Now the problem is that there isn't enough material coming out of the nozzle.

I reduced the filament diameter setting and played around with the temperature,

but the outflow is still "intermittent".

Any guesses?

 

[pm_dude 27]

print at 230C-235C and slow (20-30mm/s) for 0.1/0.15mm layers

 

[irajek 0]

How would the feeder spring's tension impact the print quality with Flex PLA?

 

[pm_dude 27]

Retraction heavy prints are hard to do with flex pla because it will flatten the filament at the extruder level and cause friction in the bowden tube.

 

[pm_dude 27]

A good tension will reduce risk of slipping and the filament guide will prevent the filament from bending between the extruder and the bowden entry.