What causes this on NinjaFlex prints?

[voodoo28]

Does anyone know why my prints have all these small bumps on the perimeter?
Printing at 250
Bead at 40
.4 hex head Prusa I3v
Retraction turned off

[jimc]

that is the ooze during a travel move and it makes a bump at the beginning of each line. i have found this to be very hard to do anything about with ninjaflex because retraction and ooze controls dont work very well. when you retract to stop this from happening it just stretches the filament back like a rubber band basically doing nothing. the stuff is just so soft there isnt much you can do with it. it doesnt have the snappy action that a regular hard plastic would have.

[voodoo28]

would it help to reduce the infill overlap?

[richardphat]

It may be a direct cause from the slicer, I myself use Cura and I can tell you it isn't the smartest thing when it comes to the patterns on cylindrical shape. You could see a line of ooze on PLA ABS

[voodoo28]

hmmm...I use Simplify3D, but have only seen this happen with this filament. This is my first time using Ninjaflex. Other than this issue , it actually prints fairly nice.

[curious aardvark]

you've got s3d set to start at a random point on each line.

It will still do it on harder plastics, but you have to look quite hard for it.

That said - try printing at a lower temperature and slower speed.

It actually says on the ninjaflex blurb to print between 210-225.
Have to admit i usually print at 240, becasue it goes through the extruder easier and I can print a bit quicker.
But slow the speed down and drop the temp and it should help with blobs.

[voodoo28]

Correct, I have "start at random point each time" selected. perhaps turning it off and reducing the speed? Yes my extruder will jam if i use a lower temp wit this filament.

[curious aardvark]

well if you turn random off you'll get all the blobs in a line - which would be dead easy to slice or sand off.
So that could work. :-)

[voodoo28]

yea, my thoughts exactly.. too bad you cant use Spiral Mode with Infill in SImplify3D. anyone have a hack for this?

[curious aardvark]

yes you can. I printed the form1 chess piece with spiral infill.
It's the only other option for infill type :-)