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Dentalight
(@dentalight)
Active Member
Trouble printing with PETG

I am new to 3D printing. I am having trouble with, I believe, slicing software. I have an Original Prusa i3 MK 3s I Emailed Prusa twice and I'm hearing crickets.
Here is my last email.
I would like some feedback from you guys and gals. I want to use Slic3r PE or Cura, but I don't know how to set them up at this point.
Thank you in advance for any insight.
Neal
I sent a question yesterday or the day before about an error message, Bed Heating Error. I have not received a response. I am pretty sure that it only happens with Slic3r PE and not with Prusacontrol. How can we resolve this issue so that I can use Slic3r PE?
I am attempting to build parts that are used as lubrication adaptors for dental handpieces, using PETG. One end of the adaptor attaches to an aerosol can of lubricant and the other end to a dental handpiece (drill). The 3D printed part is under pressure during this brief use. The lubricant leaks out between the layers. The part is strong. It cannot be broken apart easily, but is porous. I am using Prusacontrol, 20% and then 30% infill. I tried changing the temps to 240 & 70. How can I eliminate this porosity. I did not think the printed parts would be porous.
Please advise.

Posted : 27/03/2019 1:27 am
bobstro
(@bobstro)
Illustrious Member
Re: Trouble printing with PETG

For best results, log in to the online store and contact support via online chat.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 27/03/2019 2:01 am
Dentalight
(@dentalight)
Active Member
Topic starter answered:
Re: Trouble printing with PETG

Unless I am missing it, I don't see a chat button.
The only thing I see is Contact Us: WANT TO ASK US SOMETHING? YOU CAN ASK ANYTHING! 🙂

Posted : 27/03/2019 2:21 am
bobstro
(@bobstro)
Illustrious Member
Re: Trouble printing with PETG

Are you logged in with the account you used to purchase the printer? They can help you with the hardware problems.

As to leaking, FFF printing of the sort done by the Prusa MK3 will not produce water-tight surfaces. They are definitely not food-safe due to bacterial growth between layers and you'll likely need to seal the interior to get any sort of water-tight fit. Lubricants will be more difficult I imagine.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 27/03/2019 2:28 am
Dentalight
(@dentalight)
Active Member
Topic starter answered:
Re: Trouble printing with PETG

I signed in, as I am here and find no chat. If anyone knows of a place where this can happen, I'm all ears.
I don't doubt what you say about watertight sealing, but I expected a print that would or could be non porous.
This printed product does not have to be food safe or autoclaveable. Dental handpieces are lubricated before sterilization and not after. I have researched the chemical compatability of PETG and my lubricant/propellant. PETG is compatable.
Thanks for your help.

Posted : 27/03/2019 2:58 am
Mustrum Ridcully
(@mustrum-ridcully-2)
Honorable Member
Re: Trouble printing with PETG

you are signed into the forum not the store pages
https://shop.prusa3d.com/en/
contact prusa online chat system 24/7 support
log into your account on one of the prusa store pages at the link above and in the bottom right corner you will see the Chat system box click in it enter your Invoice number for you Prusa and start the chat system they do an excellent job and will take good care of you.

Posted : 27/03/2019 6:00 am
Dentalight
(@dentalight)
Active Member
Topic starter answered:
Re: Trouble printing with PETG

I finally found the chat link and contacted support. It was late last night and I had another print going with Prusacontrol. Support said it makes no sense that the Slic3r program would have anything to do with the error message, but that has been my experiance. I have no trouble with Prusacontrol but a bed heating error with Slic3r PE every time. I will try a print with Slic3r PE, making sure all settings are default this morning and see what happens.
Thanks for your help.

Posted : 27/03/2019 1:30 pm
Bunny Science
(@bunny-science)
Noble Member
Re: Trouble printing with PETG

It could be a difference in how the slicers are doing bed control change as you get past the first few layers, BUT you're chasing a secondary symptom, not the root cause.

A bed heating error occurs on the printer, not the control program. Causes of the error vary. You will need to identify and correct the heat sensing or heat production issue.

1. Bed thermistor and its wiring securely taped to bottom of heat bed?
2. Bed thermistor connector wiring not under mechanical stress at EINSY board.
3. Bed heater power screw connectors tight at EINSY
4. Bed heater wire connectors cleaned, directly contacting PC tracings and secured. Washer should be above connector, not between terminal and PC tracing.

Work flow - the following is easiest. Get this working before getting more elaborate....

Slice your model in Slic3r using a default PETG filament setting.
Export to g-code file.
Copy g-code file to SD card.
Move SD card to printer
Print from SD card.

Fuiid tight objects are not typically expectable with FFD printing. It depends on getting at least one shell continually fused without any tiny gaps in the extrusion. Start with the Prusa supplied PETG profiles. Leave the bed temperatures alone, increase your 1st layer and following layer temperatures slightly. I get very good fusion of PETG at 245C, but even then I don't expect objects to be fluid tight. That result is more the exception than the rule.

Posted : 28/03/2019 1:17 am
Dentalight
(@dentalight)
Active Member
Topic starter answered:
Re: Trouble printing with PETG

First of all, thanks to all of you who help us newbies out. There is a lot to learn with these machines and it can be frustrating.
First, the bed preheat error turned out to be a problem with the Slic3r preconfigured to raise the bed & extruder temps after the first layer. There are threads on this forum that address this issue. Basically, the bed & extruder temps will not rise fast enough and the software pops up an error. The solution is to keep the temps the same throughout the print. That solved my problem and apparently when using Prusacontol, the temps stay the same. That is why it didn't cause the bed heating error. I'm suprised that 3 different Prusa support people that helped me did not know how to steer me in the right direction.
I also had a loose belt error in the middle of this. I did not expect the belts to stretch in a couple of weeks, but they did, especially the X axis. I wish Prusa would have made the X axis adjustment parameters larger without having the screw with the extruder. There is a belt tensioner on Thiniverse that I may print that addreses this issue. https://www.thingiverse.com/thing:2740715 If anyone has used it, what are your thoughts?
As far as making these lubrication adaptors leakproof, I have solved that as well. I increased the walls to 4 and increased the extrution multiplier to 1.12. I am using 240 & 80 degrees and it is leakproof.
My only issue now is trying to make the top layer smooth. I tried to use Cura 4.0 with ironing, but it is not going to cut it. I could not get it to print the first layer, so I am back to Slic3r PE. I have not been able to use the Variable layer smoothing to work on the flat top area. My piece is a 13 mm diameter cylinder with a couple of holes through it vertically and the top layer is coming out bumpy. I am going to have to sand the top to make it work, unless anybody knows how to configure "ironing" a top flat surface in Slic3r.

Posted : 31/03/2019 11:58 pm
supermerill
(@supermerill)
Eminent Member
Re: Trouble printing with PETG

> My only issue now is trying to make the top layer smooth

> I am going to have to sand the top to make it work, unless anybody knows how to configure "ironing" a top flat surface in Slic3r.

You can download & launch my fork of slic3rPE and select the ironing pattern.
The most important thing about the top layer quality is to have the exact quantity of plastic on top. In my fork, you can add an extra "denser infill" before the bridged solid layer, and/or increase the flow of the solid layer over the bridges to compensate for bridging "drop". see wiki

I've tested it on my mk2 and it works well for pla. I didn't test petg that much, but the few of them that i printed are also good. I didn't see why a mk3 can't achieve the same results.

Posted : 01/04/2019 10:33 am
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