Printing Soft PLA with heavy retractions (using Robert's feeder)

[GCarlos 0]

Hi, I'm trying to get a successful Soft PLA print where heavy retraction is necessary.  I've been able to use all the topic posts here (and from YouMagine posts for Robert's feeder) to get pretty good results - Thank you to all.    I'm using the combo Robert/geek feeder (by sfriedri) with settings below.   This would work for something like an iphone cover but my work requires heavy retractions.  

The prints are being used to make plaster molds for clay - tiles of mini houses/landscapes.  I'm trying to avoid printing in regular PLA and re-cast in silicone. Has anyone had success with similar printing using soft PLA or NinjaFlex?  Going to make a quicker test tile and try a slightly longer yoke for a bit more pressure.

Material:  Orbi-Tech PLA Soft (from MatterHackers)

Settings in Cura:

0.1 layers

20 mm/s speed

200 mm/s travel

20% infill

Settings on UM2:

235 C nozzle

45 C bed

Retraction: 35 mm/s & 6.5mm

No oil

Green prints are regular PLA, Red is soft PLA

Edited May 24, 2015 by Guest

[gr5 2,268]

DEfinititely put oil on the filament - it won't hurt anything. I thought the oil might make holes or pockets in the print but it doesn't.

I would try using the feature in cura "cut off bottom" or whatever it's called and practice/experiment with printing those last few layers only. I had to go down to even 10mm/sec I think and a little hotter - 240C to get zero underexturions. And one drop of oil every meter or so and let the filament hang loose to the floor.

[GCarlos 0]

Thanks, I'll try slowing it down at the end and a little hotter.

[gr5 2,268]

And add oil damn it!

[Orto3D 0]

Hi,

I'm trying the same thing!

What type of oil do you add? How do you add it ?

Thanks a lot!!!

[gr5 2,268]

Any mineral oil will work. Use a light oil.

So for example: baby oil, 3-in-1 oil, sewing machine oil, penetrating oil.

Food oils are not recommended but should work fine (they can go rancid). Oils with additives like detergents (WD40) not recommended either.

Drip the oil on the filament before it goes into the bowden. One drop is enough to coat the whole bowden. Maybe slide it in and out 3 times if you have the latest "plus" feeder or if you have iRoberti feeder.

Then add two drops of oil for every meter so that it is continuously coated. I uncoil the filament and it hangs down like a long string about a meter down and make sure it's coated every 20 minutes of printing.

I just used ninjaflex with UM2+ last week and it worked great.

[Orto3D 0]

Ok! Thanks a lot!

And how should i clean it after that?

[gr5 2,268]

Clean what? The filament? Just wipe the oil off. Or leave it on the filament. The print will not get significant amounts of oil on it - it's very subtle.

Edited June 9, 2016 by Guest