Hatchbox petg

[Foulkn 0]

I started using petg a few months ago, bought 1 black and 1 blue spool. A little time tweaking and it is printing quite well for me.

I purchased 3 yellow spools of the same Hatchbox petg. I cannot get any of these spools to print without skipping. I cannot see if it is stalling the feed stepper or if the filament is slipping.

I have ran up to 265c,

I have run as slow as 10mm/s

I have reduced flow to 80%

Combination of all these.

Nothing I do seems to change the skipping.

I did notice when I first tried it that it was bubbling a lot. I was assuming moisture. Thought it was cooling the extruder locally. So I purchased a drying unit. Dried 1 spool about 36 hours. I do not notice the bubbling any more, but still skipping.

Went back to the blue and it prints flawless.

I am at a loss, not sure what to do.

Any suggestions?

[kmanstudios 1,047]

What machine and version of Cura?

Also, be aware that different colors and such can really cause a difference in your printing experience. That is why you can make and save material and printing profiles for each instance (My experience on Cura 2.4 and 2.5 in conjunction with a UM3X). Can be a bit of a pain going through a long list, but it is better than having to try and remember every little thing when you run into odd things like you describe.

But, if it is skipping, it would seem (I am guessing) to be underextruding. Try to raise the flow and see if that helps.

Also, do you hear what could be a 'popping sound' from the feeder area or binding on the filament?

A popping sound would indicate a tension adjustment is needed as it can grind and cause poor feeding.

A binding is when the filament sorta gets wound on itself and creates a friction 'knot', for lack of a better term.

There are far more experienced than myself, but just throwing stuff out there that has worked for me.

[chrisw 69]

I would use a caliper to check the filament size.  If it's too fat for your bowden tube then it can cause the skipping.

Also petg shouldn't require drying.  Usually the bubbling and maybe dripping happens when the hot end is too hot.   I haven't tried this Hatchbox brand, but usually the petg brands that I've tried run best in the 238 - 245C range.

Edited May 29, 2017 by Guest

[geert_2 421]

You could remove the bowden tube at the back end, and then try to feed the material by hand. Heat up the nozzle and see if you can easily push it through. Or remove the bowden tube at the nozzle end, and feed it manually there. At least this will give you an indication if there are any mechanical blockings.

Could it be that the filament is too thick (>3mm), or that it is squished into an oval or thin plate too much due to incorrect spring pressure in the feeder. If the spring pressure is too high for the material, one diameter might become let's say 3.5mm, and the other only 2.4mm, or so, and then it will get stuck in the bowden tube, teflon coupler or nozzle.

The PETG that I tried did work between 215 and 250°C, with lower temps around 220...225°C working best, at relatively slow speed.