ABS filament damaging bed, want alternative recommendations

Help with printing with specific plastic filaments.
lesthegringo
Posts: 76
Joined: Mon Dec 26, 2016 9:41 pm

ABS filament damaging bed, want alternative recommendations

Post by lesthegringo » Mon Jun 25, 2018 1:41 am

Guys, as posted on the hardware forum, I've discovered that the reason I was getting bad initial layers with my prints was that the PEI sheet was lifting and affecting the first few layers. Essentially it would cause small bubbles in between the layers, then over time these bubbles were growing, and joining together with the result that when the bed was hot, the PEI was essentially detached from the glass. After I replaced the bed, I out of curiosity lifted the corner of the PEI sheet on the removed bed, and it came off completely with virtually no effort.

Further investigation with a brand new bed shows that after just three prints with ABS, the adhesive layer between the PEI and the borosilicate glass bed is already bubbling and lifting. The ABS I'm using (Protopasta ABS) recommends a bed temperature of 110 degrees, which is clearly affecting the adhesive. I tried printing at 90 degrees, and ended up printing bananas as the prints lifted at the edges.

As I don't want to have to keep replacing beds after 20 prints, I need to find an alternative media to print with, one that will give a good percentage of the toughness of ABS but without the bed degradation. Clearly this means a lower temperature bed requirement.

Do you have any suggestions as to what would be a suitable alternative?

Cheers

Les

kcchen_00
Posts: 1634
Joined: Thu Feb 19, 2015 12:42 am

Re: ABS filament damaging bed, want alternative recommendations

Post by kcchen_00 » Mon Jun 25, 2018 8:53 pm

IMO, PEI is the best print surface for ABS. Doesn't need tape or messy sprays/liquids. Just need to follow a few rules with removal:
- Cool bed to under 60C, 50C is the recommended removal temp.
- Don't pry up or "knock" the print off the bed. This will cause bubbles eventually.
- Use a good removal tool that can get under the print. I like the #2 tool in this set of painting spatulas. Buildtak makes a nice tool also, but the blade is thicker and more difficult to get under the print. I use the paint spatula and work my way around the print. For larger prints, I'll follow the paint spatula with the Buildtak spatula (acting as a wedge).
- For auto-level machines, make sure the nozzle, discs and wiper are clean. This should ensure proper auto level.
- For stubborn prints, try using Isopropyl Alcohol around the edges of the object to help with release... make sure the bed temp is ~50C.

I read that you installed the modular plate system... Try flipping to the glass. The ABS should stick to the glass @110C. If you're slicer allows for adjustment of bed temp, I like to drop to 100 or 95C after 3mm have been laid down.

Hope those tips help.

lesthegringo
Posts: 76
Joined: Mon Dec 26, 2016 9:41 pm

Re: ABS filament damaging bed, want alternative recommendations

Post by lesthegringo » Mon Jun 25, 2018 11:10 pm

Thanks for the reply, I also agree that PEI is good for ABS... but I think maybe you misunderstood the problem.

The PEI is not the problem per se, it is that the adhesive layer is bubbling when you raise the bed temperature to the 110 degrees required for the ABS print. The bubbles occur whether or not you are printing, and are nothing to do with the removal of the part. Every time you heat the bed, the bubbles grow bigger, eventually so much so that the PEI lifts.

The PEI layer would be great if the adhesive was able to take the heating cycles without bubbling, but the fact is that printing ABS requires temperatures that damage the adhesive layer and therefore cause the PEI layer to separate and become uneven. Eventually it gets to the point where the initial layers are affected, and in the end the corners lift on the print as the PEI is no longer in contact with the heated bed.

I was toying with the idea of removing the adhesive residue from the bed that the PEI layer came completely off, and trying that with glue sticks, painters tape or thinned white glue as a a surface prep. As I already have the bits, it's a 'free' trial. I thought about flipping the modular bed over and using the glass side, but of course I would still be heating the PEI and adhesive to 110 degrees so the damage would continue to be done. After the PEI layer eventually drops off it is an option though

However, if there is a good alternative to ABS I'm still listening!

Cheers

Les

kmanley57
Posts: 1079
Joined: Sun Feb 01, 2015 3:53 pm

Re: ABS filament damaging bed, want alternative recommendations

Post by kmanley57 » Tue Jun 26, 2018 5:51 am

You may want to try and avoid printing anything but the 'soft' filaments on the bare glass. The shrinkage of the plastic will likely micro fracture the glass sooner or later and make it chip even with the use of a glue stick on it. I have even had to replace the thick PEI sheets due to them cracking over time from the plastic shrinkage and falling apart while replacing the adhesive sheet. One of the reasons the adhesive fails is the tiny near invisible cracks that develop are letting air in and drying out the adhesive. The thicker sheets I currently use have tended to fail from the outside edges in, until the whole plastic sheet came off the dried adhesive.

But in the long run the plastic sheet/film is cheaper than the glass plate to take any damage.
I will express my CRAZY ideas at any time! So you have been warned. None of my opinions are Lulzbots and can be wrong at any second.

kcchen_00
Posts: 1634
Joined: Thu Feb 19, 2015 12:42 am

Re: ABS filament damaging bed, want alternative recommendations

Post by kcchen_00 » Tue Jun 26, 2018 7:56 pm

lesthegringo wrote:
Mon Jun 25, 2018 11:10 pm

The PEI is not the problem per se, it is that the adhesive layer is bubbling when you raise the bed temperature to the 110 degrees required for the ABS print. The bubbles occur whether or not you are printing, and are nothing to do with the removal of the part. Every time you heat the bed, the bubbles grow bigger, eventually so much so that the PEI lifts.
Hmm... I didn't experience this with the PEI on my modular bed or for PEI I've applied in the past. At least not with heating the PEI to 110C. I do get bubbles eventually from part removal, which also cause the bubbles to grow... but the bubbles do stop growing.

I have read that recent PEI beds have had issues when heated past 100C... could be something happening at the factory.


Learning from experiences and observations of other members is why I continue to participate in these forums...

cantieny
Posts: 17
Joined: Thu Jun 18, 2015 8:55 am

Re: ABS filament damaging bed, want alternative recommendations

Post by cantieny » Sun Jul 15, 2018 3:58 pm

I had pretty bad bubbling on my PEI sheet. I was about to replace it when I started looking into removable build plates. I ended up buying some Wear-Resistant 1095 Spring Steel 0.0120" Thick, 12-3/8" Wide, 3 Feet Long from Mcmaster/Carr (9075K185). I put the new PEI sheet on that. I added about 12 high temp magnets below the glass and heater. That created a DIY removable flex build plate. I got 1 for my Mini and 2 for Taz4's out of the one sheet of steel. With better planning I might have gotten 2 for the Mini. I have to run some binder clips at the edge of the plate to keep it from shifting. The magnets will hold the steel flat but it can still slide a little. I used these high temp magnets on the Mini (KandJ Magnetics D81SH). They have to be thin to fit between the heater and the aluminum plate. They also have to miss the button head screws in the aluminum plate. I pushed them in from the sides so I didn't break the glass. They stick to the metal strips in the heater. I used bigger 1/8" thick magnets on the Taz4's but I can't remember the exact part number. I think they were DA2SH. A lot more room on the Taz. Adjust Z for the added build plate thickness: On the Mini I adjusted the Z-offset (M851) from Z-1.31 to Z-0.70 but that would need to be verified on each machine. On the Taz4's I adjusted the Z endstop screw.

I also set my part removal temp 5 degrees below my print temp. The bed runs forward almost as soon as the print is done. I remove the build plate with the print. Let it cool (hold in front of a fan) for a minute and flex the plate to pop off the print. The PEI surface has stayed stuck to the steel through many prints and I can get parts off the bed without prying and having to let the bed cool to 50c (I print mainly ABS). I think it's the prying and not letting the bed cool that led to most of my bubbles. Big flat prints pop right off even if I have used glue stick on the plate to keep them from warping.

I don't think I could ever go back to printing without a removable build plate!

***** Edit*****
Ignore the info below. It turns out that one of the purple heated bed wires failed in the bed harness. I have a new bed harness on order. I may zip-tie the new harness on the outside of the cable chain. Perhaps that will allow the wires to bend over a larger radius and not fail.
***** Edit*****

Word of caution: I am now having an issue with the bed heater on the Mini (3 years old?). I don't think the magnets or the steel plate are the issue. They have been on there for the last 6 months, but the heater didn't break before they were on there so who is to say? YMMV.

olantigh
Posts: 33
Joined: Fri Feb 02, 2018 11:56 am

Re: ABS filament damaging bed, want alternative recommendations

Post by olantigh » Sun Sep 16, 2018 3:07 pm

On the TAZ 6 the PEI is listed as a consumable, The ABS print temperature I use is at 105 and with Luzebot's advice I now move the printing around the plate to make the PEI last longer.
I found that ABS if done this way makes the surface last about 40+ prints in that exact place (my prints last about 11 hours plus at a temperature of 229) I still an occasionally get a warped print every now and again but its rare- I've found techniques of printing things on their sides and upside down- makes the print longer but it looks much better.
ABS is an unforgiving material, wrecks your PEI in both lifting it with bubbles and it scratches very easily- if you buy a replacement direct from here its about a £40 for each one but you do get a guarantee for a month.
And its a messy job stripping it off and sticking a new one on- I've done it three times now- and only had my machine for six months.
Hopefully someone in the Lulzbot company is inventing a new PEI surface that doesn't self destruct and last a bit longer!...

BusterCherry
Posts: 13
Joined: Mon Nov 27, 2017 5:19 pm

Re: ABS filament damaging bed, want alternative recommendations

Post by BusterCherry » Fri Oct 05, 2018 6:15 pm

I'm glad I found this thread as I've been having similar troubles. I thought that the modular print bed system would be the solution, but I still wind up with bubbles. The key problem seems to be with the separation of the PEI and the adhesive. Perhaps it would be a better approach if a PEI sheet could be mechanically mounted instead of using the dual sided adhesive tape. Several folks use clips, but there's gotta be a more robust method of attachment. I've searched for PEI sheets in greater thickness (~5 mm) to no avail. It would be nice to do away with the glass entirely and just use a thicker plate of PEI.

BusterCherry
Posts: 13
Joined: Mon Nov 27, 2017 5:19 pm

Re: ABS filament damaging bed, want alternative recommendations

Post by BusterCherry » Fri Oct 12, 2018 5:01 pm

cantieny wrote:
Sun Jul 15, 2018 3:58 pm
I had pretty bad bubbling on my PEI sheet. I was about to replace it when I started looking into removable build plates. I ended up buying some Wear-Resistant 1095 Spring Steel 0.0120" Thick, 12-3/8" Wide, 3 Feet Long from Mcmaster/Carr (9075K185). I put the new PEI sheet on that. I added about 12 high temp magnets below the glass and heater. That created a DIY removable flex build plate. I got 1 for my Mini and 2 for Taz4's out of the one sheet of steel. With better planning I might have gotten 2 for the Mini. I have to run some binder clips at the edge of the plate to keep it from shifting. The magnets will hold the steel flat but it can still slide a little. I used these high temp magnets on the Mini (KandJ Magnetics D81SH). They have to be thin to fit between the heater and the aluminum plate. They also have to miss the button head screws in the aluminum plate. I pushed them in from the sides so I didn't break the glass. They stick to the metal strips in the heater. I used bigger 1/8" thick magnets on the Taz4's but I can't remember the exact part number. I think they were DA2SH. A lot more room on the Taz. Adjust Z for the added build plate thickness: On the Mini I adjusted the Z-offset (M851) from Z-1.31 to Z-0.70 but that would need to be verified on each machine. On the Taz4's I adjusted the Z endstop screw.
Would you mind posting a photo of your setup?

mburko
Posts: 7
Joined: Thu Dec 21, 2017 11:21 am

Re: ABS filament damaging bed, want alternative recommendations

Post by mburko » Thu Nov 29, 2018 2:42 pm

PEI seperating from the glass on the very 1st ABS print. Just applied a fresh sheet of PEI to the Lulzbot brand's Modular bed's glass. Used 468MP Transfer Sheets, as they are called. They employ 200MP adhesive.

I print Esun ABS with 260c extruder, 110c bed. Part is about 1 inch wide and 5 inches long. ABS shrink forces at the 1 inch ends are more than the 200MP can resist at 110c or even 100c. PEI separates from the adhesive. I know that from the PEI replacement process. Adhesive is always stuck to the glass.

Hunted around for specs on 3Ms 200MP the adhesive used in the 468MP tape/ sheets. While that is what everybody is selling it for bonding the glass and PEI it is not rated for ABS temperatures nor recommend for bonding plastics.

300MP is recommend for bonding plastic. Have yet to find a source for Transfer Tape sheet made with it. Not rated for the 100+ temperatures. Still looking.

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