Hi all,
Lately I’ve been taking my first steps into printing with a Makeblock mElephant . I have a roll of PLA and a roll of PETG to try both these materials, both from the brand Octofiber. (1.75mm) Printing with the PLA has been a walk in the park, I tried the model that came with the printer (an elephant phone holder) and some 3D-models from Thingiverse. Because the printing seems so easy i started to find out differences in printing speed, layer height, infill, etc. using Cura for slicing the models.
Next I wanted to try the PETG, and from the website it has the same settings to print it (210c, printing speed 30-60mm/s). This didn’t work at all (at 60mm/s), the prints became wired, ugly, so I tried again. This time I went with 240c and lowered the speed. Everything seemed nice, the print started to come out smoothly, solid and without any wires. After 15 minutes or so, the filament didn’t come out of the nozzle anymore. Because the extruder kept ‘pusing’ it through, the filament just came out of the side of the extruder unmelted.
The third try did exactly the same thing, I searched online seeing it could be a clotted up nozzle so I cleaned with with a PLA cold pull. Now what can I do or try to get a full clean print with the PETG? What am I doing wrong here? Can anyone give me a hint in the right direction? As said, I’m new to 3D printing so any help is welcome.
Thanks,
QHuizer
SOC3D
June 12, 2016, 2:02pm
2
PETG likes to clog. If you have the option of fixing your extruder a bit it will help. By that I mean you have a drive gear and pulley with a feed tube underneath. If it’s possible to move the feed tube closer to the gear or insert a piece of pfte it would prevent the whole coming out of the side of the extruder issue. Some things to try with petg, use a single speed for the print. Set your print speed to say 20mms and all of your speed multipliers to 100% then set your travel and retraction speeds to 100%. And here is a ton of advice from makergears forum. Print Settings for PETG: eSUN Solid Black Filament - MakerGear Forum
Thanks for your reply, I read your link and a lot of different websites and changed a lot of settings:
* soften the retraction
* slightly underextrude (96% flow in cura)
* slightly larger z-offset
* have all the printing in the same speed, and slow (35 mm/s)
It all seems to go fine until it starts with the infill, i hear loud clicks coming from the extruder and it can’t
push in the filament anymore. Any other suggestions?
SOC3D
June 13, 2016, 2:25pm
4
Before going through more headaches split the speed in half and see what happens. Have you calibrated the filament diameter and extrusion multiplier? What type of printer and extruder? Sorry if that information is above I can only see one reply when responding.
Will try at half speed later. I wonder what you mean exactly with calibrating the filament and extrusion multiplier? The filament is at 1.75 in Cura and the extrusion multiplier is at 96. I read that a tiny underextrusion could really help to get clean PETG prints so thats why i lowered it from 100 to 96.
I have a Makeblock mElephant , which is based on the Prusa i3. I can’t find the exact extruder type. If you know where I can find it I’d be happy to provide the information.
SOC3D
June 13, 2016, 4:52pm
6
1.75mm filament is not 1.75mm. When you print a line that is supposed to be .2mm (200 micron high) by .4mm (400 micron wide which is a typical nozzle width) you actual have to calibrate your printer to hit those numbers. Printers are not smart enough yet to do so automatically. Talk Manufacturing | Hubs
When I find some time I will walk through those steps. Thanks a lot for the link (bookmarked it) and I will update with my findings.
I use PETG all the time. In fact, it’s one of my most used filaments. Printing at at 240c 60mm/s. However, my machines have fully redone extruder setups, each capable of reaching 400c. If your machine has trouble keeping up with the filament, print slow. If you like printing with strong materials, I would suggest upgrading your hotend.
If not, a little vegetable oil pored into the hot end goes a LONG way. After dripping in some vegetable oil, run some filament through while whipping vegetable oil on the filament as it is fed into the printer. If your current hotend uses a PTFE tube, just ditch the PETG and grab some PET+ from made solid. It has similar proprieties. They sell it on their site and on amazon. PTFE tubes are like death the PETG. Although you can probably get through the rest of your spool with the oil.
Here’s an update: i measured the width of the filament and it’s indeed not 1.75mm but 1.80mm, did find some other settings and fiddled around again but I keep having the same problem. The filament won’t push through the hot end after ± 15 minutes. I added some pictures which might help. The company who makes the filament (Octofiber) suggests printing at 210. Maybe 230 is too high? Though i read a lot that PETG likes higher temps and lower print speeds.
