Pursa Mk3 New user Printing Pursa PET problems  

Re: Pursa Mk3 New user Printing Pursa PET problems

When you say that you had to increase Z height, do you mean you increased the live Z value (negative)?
That is what I have to do with PETG , I have to LOWER the nozzle by about 50...60 microns, meaning I have to increase from my Live-Z value for PLA of -450...-460 to a value of -510...-520 for PETG.
After getting the first layer dialed in for PETG I have had no issues with the PURSA PET settings of Slick3r and several different brands.

Stringing and oozing was an issue after leaving the filament in a non-sealed box for months, but after putting the filaments into an airtight box with dessicant this disappeared again.

If you really raised your nozzle, try lowering it until you find the right Z-level, and post photos if you still have an issue.

Re: Pursa Mk3 New user Printing Pursa PET problems

[...] 6. So now the big question id the default infll speed at 200ms in the pursa settings just to fast or am i missing something.
IME the 200mm/s speeds are too fast, yes. Fortunately, you can test this easily by simply dialing back the speed on the front knob during the print. If you're using Slic3rPE, it should be setting the max volumetric speed (MVS - See Filament settings->Advanced) to 8. That should limit speeds to what the hotend can handle. Try slicing the part, saving the gcode then looking in Preview mode. The Speed mode will show you how fast it's actually moving, the Volumetric rate mode will show you how much plastic it's moving.

If slowing down via the front knob works, try adjusting the max volumetric speed setting back a bit, perhaps from 8 to 5. PETG likes to stick to itself, and going too fast might cause it to bunch up and start sticking to your nozzle. I do usually raise (make less negative) my Live-Z by 0.02mm for PETG.

Re: Pursa Mk3 New user Printing Pursa PET problems

I do usually raise (make less negative) my Live-Z by 0.02mm for PETG.

Very interesting indeed...
I remember reading about PETG requiring slightly raised nozzle heights to prevent it from sticking to the print bed too much, but when I started working with it myself it worked best for me to lower the nozzle. I am getting reliable results that way.
The print does stick to the bed a lot when cold, but I learned that it pops off easily when the bed is still warm, like half cooled down from printing temperature.
But thinking of it, I do recall that the first layer was a little rough which would indicate a too low nozzle.

I need to go back and try with different first layer heights...

Re: Pursa Mk3 New user Printing Pursa PET problems

Hi All

Thanks for your comments
Progress has been made
I have altered the max volumetric speed (MVS - See Filament settings->Advanced) to 8.
and reviewed the print speed in silc3r thanks for the tip.
Prints are now much improved as the pictures show
I found a reduction to 80 percent improved the infil again. as show in the pics.

I'm surprised that the Pursa edition of the slic3r does not do this for you.
Thanks for the advice.
Any further guidance would be most welcome.

Regards

Mark

Re: Pursa Mk3 New user Printing Pursa PET problems

Hi
Looks like you can only attach 3 images so here are some more

Re: Pursa Mk3 New user Printing Pursa PET problems

[...] I'm surprised that the Pursa edition of the slic3r does not do this for you.
It does, but perhaps not in the way you expect. If you adjust MVS, all of your speed settings become maximums. The slicer will get up to those speeds but only so long as MVS is not exceeded. You can see this if you slice your part, save the gcode then spend time in preview mode looking at speed and volumetric flow options. (Notice that I set MVS to 8 in the pics -- I need to update the settings pics.) You'll see that Slic3rPE respects your speeds to a point limited by MVS. The specifics will depend a lot on the size and complexity of the part you print. I've got more notes on this here. "Speed" is a really deceptive setting. You rarely will hit those speeds in most prints, so it can be a surprise and cause problems when you finally do.

Re: Pursa Mk3 New user Printing Pursa PET problems

When you say that you had to increase Z height, do you mean you increased the live Z value (negative)?
That is what I have to do with PETG , I have to LOWER the nozzle by about 50...60 microns, meaning I have to increase from my Live-Z value for PLA of -450...-460 to a value of -510...-520 for PETG.
After getting the first layer dialed in for PETG I have had no issues with the PURSA PET settings of Slick3r and several different brands.

Stringing and oozing was an issue after leaving the filament in a non-sealed box for months, but after putting the filaments into an airtight box with dessicant this disappeared again.

If you really raised your nozzle, try lowering it until you find the right Z-level, and post photos if you still have an issue.

I need to correct my statements about Z level for PETG.
I found out that my PLA settings at -460 were not ideal. I found the best PLA setting at -500 with the "large square" printing method.
And I lately had difficulties getting PETG to stick, succeeded again at -510...-520 but would actually like a slightly higher nozzle

Re: Pursa Mk3 New user Printing Pursa PET problems

the photos you posted still show issues with your infill; did you manage to tweak your settings?

I'm printing with Colorfabb XT using Prusa control and I'm facing similar problems.

Re: Pursa Mk3 New user Printing Pursa PET problems

Hello everyone.

Actualy, I was looking for somme informations about infill speeds in slic3r, that I suspect to be WAAAY to high.
I recently had to print ASA (love it), PCPTFE, and other stuff.
I had plenty of printings beginning fine but go to an issue after somme layers. I suspected there was something a bit too demanding, that the printer could handle for a short time, but resulting in an issue after a longer time.
And I suspect this infill speed of 200mm/s is really way too high.
ASA prints like mny other materials round 40mm/s. Of course, you can ask you printer to print it at 200mm/s for a second, or some.
But pressure varies too much in the hotend, the extruder can't handle it, and , after some time, this leads to an issue.

I tried to print tsome parts with a completely uniform speed, of 40mm/s. SO I set all speeds at 40mm/S in Slic3r. ASA, PETG, PCPTFE, even PLA. Of course time increases. But I could finally print very difficult materials like PC and PCPTFE without any issue.

So , I guess I'll have to test different settings to find the best ones, but, imho, 200mm/S is too fast. A LOT too fast.

Benoit