TPU print - Perimeters not sticking well to main body of print
I am printing a flat item about 1mm thick and find that the bonds on the internal area (inside the perimeter) has strong bonds. However, the outer perimeters do not have strong bonds and easily pull away from the main body. If I fiddle with the band of perimeter that pulled away, I find that that band then can separate into the individual printed lines.
Any suggestions on the main culprit for this? Any pointers in a direction appreciated. The image should help clarify what my words are not conveying.
For those interested, my TPU printing has been working great with no mods. Placing TPU (Overture TPU - not high speed) going through filament sensor and through all standard tube. This machine is incredible compared to my MK3SPlus I have. Loving the upgrade!
Please save your project as a .3mf file
Files > Save Project as
Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.
Cheerio,
RE: TPU print - Perimeters not sticking well to main body of print
I guess that would have been good to do in the first place. Thanks for the suggestion. Here is a 3mf file for this.
Loopie_TPU_V01_PrusaExport
Adding a file is a little confusing to me as it looks like it is meant for media. Hope this works.
Something else to note is I just got the thermal run away error. I have not had time to look at the wiring etc yet. I wonder if this could be related?
RE: TPU print - Perimeters not sticking well to main body of print
Oh an if it helps...... Here is a pic I just took printing one where the print is only a layer or 2 in. You can see the outer layers are not sitting tight to the part in some places.
RE: TPU print - Perimeters not sticking well to main body of print
Most Flexible TPU Profiles use an Extrusion Multiplier of Greater than 1
this means the extruder tries to output a thicker strand shat may well bond to adjacent strands, more effectively.
it looks like your Extrusion multiplier is only set to 1.
could you try 1.1 extrusion multiplier and see if that helps?
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: TPU print - Perimeters not sticking well to main body of print
lol I feel like a dumb dumb. I have read about extrusion multiplier for flexibles and completely blanked out on it. Never even occurred to me.
Joan, you nailed it. Thank you. I moved up to 1.1 extrusion multiplier and its way better. I will play more with it and see where I settle in. Currently trying another at 1.15 just to see the effect on this.
Thanks!!
RE: TPU print - Perimeters not sticking well to main body of print
I am very good at missing the obvious, too!
just goes to show, how seeing the project file can identify issues!
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: TPU print - Perimeters not sticking well to main body of print
Well I guess I am not out of the woods.
I played with the extrusion multiplier and it makes marginal difference.
The inner layers look good but still having some issues with the perimeter.
I found one post talking about maybe needing to adjust the K factor (I have not done this just putting it out there for thought for those considering chiming in on this).
Just to be safe it was not the stock tubing run that others have talked about for TPU I hung my filament spool above the printer, placed a piece of filament in the side filament sensor to fool the printer, inserted a 2-inch piece of tube at the extruder and ran the filament down into the extruder from above. This gave a clean run and easy pull for the printer to get the filament.
My prints are failing like an hour (Sucks to go to bed expecting a cool thing on your printer in the AM and finding a fail). The printer believes the print completed. into the print and what I find is the filament is bunching up right on the bottom side of the gear just before entering the metal tube. Image attached.
I started another print this morning and went about my day. I came back to see it working just fine and set about other work in my space. My timing was lucky I guess. I started hearing a clicking sound, so I paused the print. What did I find? Yup, the filament bunched up by the bottom of the gear again. Image attached.
I removed and replaced the filament and resumed the print. But also backed the idler screws out a little over a turn each since I have also read that these may need to be looser for TPU.Any more pointers greatly appreciated. Ugh! I want to make "things" not be a constant printer tweaker. lol
RE: TPU print - Perimeters not sticking well to main body of print
With Idler screw backed out it lasted for a 4 hour print (not sure if it was a help or coincidence). But the next print failed the same way. Got about an hour in then the clicking sound started. I was a little later this time and not sure I caught it in time (just restarted the print).
Something to note is I do not think this is a nozzle clog or anything like that. When I pause the print and open the door to un-jam the filament, I am able to pull the filament out from the nozzle easily (after pulling it free from the gear area of course) and what I get is a smooth undamaged section of filament with a nice little cone shape of the inside of the nozzle. Both times I have pulled the filament after the jam were the same, nice clean looking nozzle cone shape.