PET+ Trouble with infill

[entomophile 9]

I just started printing with PET+. I printed a bunch of twin test cylinders to find the optimal print temperature. At 220C the surface finish is perfect and layer bonding is very strong. So I started printing some larger objects. The bottom layers and outer walls print perfectly but as soon as the infill starts the lines break down and the infill ends up a mess. It looks as though not enough material is being extruded during the infill. I tried slowing the infill speed to the same as the print speed (30 mm/s) with no luck. I also tried increasing the print temp to 230C thinking the material wasn't flowing fast enough, but that didn't help. Could this be a retraction issue? The retraction settings on my UM2 are 4.5mm @ 25 mm/s. The Cura retraction settings are 1.5 mm minimum travel, combing off, 0.02 minimal extrusion, and 0 Z hop.

Here is a pitcure with a few infill layers printed after the bottom layers.

[entomophile 9]

OK, looks like I fixed the problem myself. I reduced the retraction length to 3 mm as recommended by MadeSolid. I really didn't expect 1.5 mm to make that much of a difference but I guess it does. I also decreased my infill from 20 to 15%. The infill is still a little messy, but at least it is complete.

[chrisw 69]

Your printing temps seem very low even after the increase to 230. I've had best reslts using PET+ at 245 - 253 in my UM2 with a .6 nozzle, 38 mm/s speed.

Bed temp: 70, fan at 25%

[rigs 735]

Melting point around 245°

create PET+ profile

https://www.youtube.com/watch?v=_OtmB6tTX60

Edited July 19, 2015 by Guest

[entomophile 9]

Sorry for the late reply, I was expecting an email notification when I received a response. Anyway, you were both correct. I was printing at too low a temperature. I was misled by the PET+ printing temp specs listed as 220-250. I should have checked the MadeSolid printer settings first. Thank you1

[gr5 1,708]

In your profile settings you can make it so you get emails.