PEI Film Woes

A forum dedicated to the stock LulzBot Mini 3D Printer
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bladerunner
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PEI Film Woes

Post by bladerunner » Sat Jan 28, 2017 2:29 pm

I used my Lulzbot Mini for about a month and then I started having issues with prints not sticking to the bed. After speaking with customer support they recommended using 10% IPA/Water mix and a high grit sandpaper to lightly roughen up the surface. After doing this, the prints stuck great for awhile but then the PEI film started bubbling up in some areas making it nearly impossible to print.

Question is, how many hours of use is reasonably expected to get out of a sheet of PEI? Didn't seem like mine lasted that long and Im not a heavy user.

Also, does anyone know if the box comes with a replacement film? I could have sworn it did but can't seem to find it in my supplies. I could be remembering wrong though.

Thanks!
Michael
Lulzbot Mini
.5mm Dispenser Nozzle

ScottW
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Re: PEI Film Woes

Post by ScottW » Sat Jan 28, 2017 5:13 pm

bladerunner wrote:I used my Lulzbot Mini for about a month and then I started having issues with prints not sticking to the bed. After speaking with customer support they recommended using 10% IPA/Water mix and a high grit sandpaper to lightly roughen up the surface. After doing this, the prints stuck great for awhile but then the PEI film started bubbling up in some areas making it nearly impossible to print.

Question is, how many hours of use is reasonably expected to get out of a sheet of PEI? Didn't seem like mine lasted that long and Im not a heavy user.

Also, does anyone know if the box comes with a replacement film? I could have sworn it did but can't seem to find it in my supplies. I could be remembering wrong though.

Thanks!
Last question first -- No, the printer does not come with a spare PEI sheet. They are about $25, available from Lulzbot directly, Amazon, and various other suppliers.

I am on my third PEI sheet, so I'll give you my experiences....

My first PEI sheet started getting bubbles after just 3 weeks of use. I had not been real careful about removing prints at 50-60C, sometimes allowing the bed to fully cool to room temp, and Lulzbot Tech Support pointed to that as the likely reason for bubbles. But they still sent a complete replacement bed with PEI under warranty, and I installed that.

That replacement, with me being super-careful about always removing parts while the bed was 50-60C, lasted about 3 months before starting to bubble.

I bought a 3rd replacement PEI sheet directly from Luzlbot, and replaced it myself. I also bought a very thin, wide painters knife to remove parts. I have been printing on that sheet for 7+ months, and it still looks like brand new with no sign of any bubbles.

Now it is possible there was something wrong with the first two sheets, like bad adhesive or something. But I think most of the longer life with the 3rd sheet is attributable to always removing at 50-60C, and using a very thin painter's knife, held flat to the bed, to remove prints gradually without a lot of force. Another contributing factor MAY be bed temp; I initially used HIPS and ABS exclusively so the bed was always at 100-110C. I gradually started using PETG/Nylons about half the time, with the bed around 75C, so the lower temperatures may have something to do with longer life as well.
Last edited by ScottW on Mon Jan 30, 2017 5:24 pm, edited 1 time in total.

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bladerunner
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Re: PEI Film Woes

Post by bladerunner » Sat Jan 28, 2017 5:42 pm

Scott,

That's very useful information, thank you. I started with HIPS and ABS as well, and found after much frustration that PETG was the way to go. I'll give warranty a call and see what they have say.

Thanks again!
Michael
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.5mm Dispenser Nozzle

ScottW
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Re: PEI Film Woes

Post by ScottW » Sat Jan 28, 2017 6:00 pm

bladerunner wrote:Scott,

That's very useful information, thank you. I started with HIPS and ABS as well, and found after much frustration that PETG was the way to go. I'll give warranty a call and see what they have say.

Thanks again!
I know around the time I bought mine (4Q 2015), there were a lot of people reporting bubbles and replacement under warranty seemed to be pretty common. I believe AO subsequently changed how the adhesive was applied, using a heat process, and that seems to have greatly reduced the failures. The PEI is now generally viewed as a "wear and tear" item, and warranty replacements are less common. But if yours is only a month old, and you've followed proper removal (not "prying" but separating, and doing so while 50-60c), then AO may conclude it was a defect and send you a replacement film. Certainly worth a call!

I eventually bought a complete spare bed assembly -- glass, heater, PEI -- to have on hand. I figured that would allow less down time for the next time the PEI needs replacement, since I can just swap in the spare bed, start printing, then replace the PEI on the other one at my leisure. I also decided it would be good to have a spare heater, thermistor, and glass on hand in case any of those failed.

Good luck and happy printing!

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bladerunner
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Re: PEI Film Woes

Post by bladerunner » Thu Feb 09, 2017 3:51 pm

No luck with warranty replacement here. I talked to customer support and emailed them pictures and they said it wasn't warranty item, because the bubbles were caused by improper removal of parts. I always made sure to remove the parts at the recommended temperatures. Oh well, I bought a new one that supposedly has an improved adhesive on it. We shall see how it goes. Thanks!
Michael
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ScottW
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Re: PEI Film Woes

Post by ScottW » Thu Feb 09, 2017 4:06 pm

bladerunner wrote:No luck with warranty replacement here. I talked to customer support and emailed them pictures and they said it wasn't warranty item, because the bubbles were caused by improper removal of parts. I always made sure to remove the parts at the recommended temperatures. Oh well, I bought a new one that supposedly has an improved adhesive on it. We shall see how it goes. Thanks!
Sorry to hear that... But hopefully your luck with the replacement will be as good as my 3rd one -- it has been "going and going" {imagine graphic of Energizer Bunny here}, and still looks like new. Only maintenance has been to lightly sand it with 1500grit a few times.

Did Lulzbot Support mention the "improved adhesive", or say when they started using it? Perhaps that's why my 3rd one has done so much better, although I bought it ~June-2016, so if that was the case then I would have expected your machine to have had that from the start.

dsplawski
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Re: PEI Film Woes

Post by dsplawski » Thu Feb 09, 2017 4:21 pm

I've had mine for a year and the PEI sheet has had bubbles for ages. I haven't had any issues with prints sticking to the bed, quite the opposite actually. My most recent ABS print stuck so well that I think ripped a hole in the PEI sheet when removing it. At least now I have a place to push the air bubbles out.

On a side note, I recently saw a print bed that used a mirror instead of regular glass. It looked freaking awesome so it I ever end up getting a second setup like ScottW, I'm going to source out a chunk of mirror to stick the PEI sheet to.

KerrFab
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Re: PEI Film Woes

Post by KerrFab » Fri Feb 10, 2017 4:56 pm

I have found that if you are printing to close the PEI, the parts stick "to good", need to make sure that you calibrate your z-axis. Also I started using blue painters tapes over the PEI, do not need it for non-sticking, but it makes the first layer more of a matte finishing (with ABS, have not tried any other filaments) and I like the look. My current PEI is 6+ months old and no real issues, except it is starting to get some small imperfections in it and sometimes these show up as small lines or dimples. The painters tape also helps hide these. First PEI had to be replaced from having to pay "stupid tax" (removing parts with sharp object and not paying attention to bed temp).

sforeman
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Re: PEI Film Bubbles

Post by sforeman » Sat Feb 11, 2017 7:42 am

I suspect my cause of bubbles is either the initial adhesive or the initial installation.

All of the bubbles under my PEI are on the back third of the bed and the majority of my prints do not cover that area. I've only been printing with my TAZ 6 for about 5 weeks.

When it becomes a sinficant enough issue, I'll replace it myself. I did the install of PEI on my other printer and it's been fine for 6 months.

Neamerjell
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Re: PEI Film Woes

Post by Neamerjell » Fri Feb 17, 2017 2:14 am

This is good info.

In contrast with so many people who had problems trying to get their print to stick to the bed, I had a tough time attempting to remove stubborn prints from my bed. I had read suggestions in the forum about heating the bed to about 60-80C (just below the glass transition temperature of nGen, the material I was printing with). It worked. My prints came off much easier while the bed was warm instead of room temperature.

So, I think most of the bubbles you've been seeing have probably been caused by the strain of removing the prints from the bed. The heating of the bed softens the material slightly and thus relieves some of the strain.

Its a win-win: Not only do our PEI sheets last longer (news to me from reading this thread) but our prints will be easier to remove.
"To err is human. To really foul things up requires a computer!"

*Proud owner of a brand new Lulzbot Mini

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