printing very flexible

mig127 · January 23, 2014

I was wondering if it would be possible to print an extreme flexible fillement with the UM. There are a couple of flexible pla,s out there. But i came a cross a site who has a rubberlike quality. The problem was that it was not usable on a bowden extruder, i don,t fully understand why. I found the fillement on recreus.com

Does anybody know a different fillement with such a flexible quality?

What would you have to hack on the UM to make it work? Is it even possible?

Dim3nsioneer · January 23, 2014

It looks to me as if the material is thicker than 3.00mm which is the absolute maximum thickness with an Ultimaker. If the material is thinner, there are some ways to get also a flexible material to slip through the Bowden tube.

Maybe you have a look at this thread: http://umforum.ultimaker.com/index.php?/topic/3440-advice-for-flexible-material/

tommyph1208 · January 23, 2014

Apart from the material being too thick for the 3 mm. bowden tube and hot end of the UM, it has been reported that you need to print extremely slow with flexible material (10-20 mm./s.), disable all retraction and add a little bit of oil to the bowden tube to remove some of the friction from the rubbery material

jhertzberg · January 23, 2014

I have printed a few things with the Makergeeks Flex EcoPLA. I also tried (unsuccessfully) to print with 3mm Eagle Blue 80 EC Polyurethane Belting.

The issue with the bowden is that you are essentially trying to push a string uphill. If the filament is too soft and its diameter isn't a perfect match to the inner diameter (ID) of your bowden, it will either kink up or bind in the bowden. If it kinks up (gets waves), you may still get it to feed all the way to the hot end, but flow rate control will be unreliable, and retraction won't do anything to remove head pressure.

There are a few things you can try to get it to work. Print very slowly, 20mm/s or less. Oil the inside of the bowden. It sounds crazy, but if you put a drop or two of machine oil on a regular piece of PLA and run it back and forth through the bowden you will get a little less friction and the oil won't damage the print. If that does not work, see if you can obtain a couple of spare bowdens with slightly different IDs. Measure your filament diameter and use the bowden that is the best match.

Beyond that, you would have to heavily mod your UM to run without a bowden. There are a couple of threads on this board discussing that:

http://umforum.ultimaker.com/index.php?/topic/2544-small-steppermotor-for-direct-extruder/

http://umforum.ultimaker.com/index.php?/topic/3199-crazy-idea-about-feeder/