Problem SOLVED : Corners lifting on parts while printing

Was hoping someone could help with this issue I’ve been having.

I print mostly in HIPS, but also on occasion in PLA, and this problem happens with both filament types (to a lesser extent on PLA). HIPS is the worst offender for me.

What happens is the part starts to distort as the edges pull away from the bed. This has been happening with my printer ever since I got it. For the most part I haven’t printed anything that’s taken a REALLY long time to print so it hasn’t bothered me much. What I do notice is that the retraction is more pronounced the thicker the part is. If for example I printed a triangular part, the thicker part would retract more than the thinner end.

Here are some pictures of the most recent failure…

As you can see the part sitting on the print bed, the corners have lifted and distorted. The bottom shot shows how warped the edge is as a result of the part pulling away from the bed.

In this case printing eSun HIPS black, the hot end temperature was set to 240 degrees and the heated bed at 110. If I keep it any less than 110 the part won’t stay on the bed at all. I am thinking that it’s heat related. The PEI film is brand new, and was cleaned before the print was done.

I am guessing that the solution would be to get the part to stick better to the bed and use less heat… but how would that be accomplished. Sure I can turn the heat down, but then what’s the point of the heat as it doesn’t do anything to keep the part stuck to the bed while printing.

This is me stumped!!!

Any help or comments would be very much appreciated.

You have a pretty good starting contact pattern there, so I think you are mainly getting tripped up by heat contraction. Try printing with a 6mm brim and a 10mm tall skirt layer to start. Also if your printer is in a colder area you may need some form of enclosure. You can also try starting with a thicker 1st layer height to get better adhesion. A turkey roasting bag can work as a temporary enclosure if you want to try one out. I would also try lowering the nozzle temperature so there is less of a thermal difference between the cooling layers and the new printed ones. Possibly also try lowering the. Bed temperature to 92. At 110 on pie the lower layer might actually be getting warm enough to partially melt and separate.

Thanks for your comments.

I’m very confident that my 1st layer adhesion is good. I used an attachment with a dial indicator. Three of the four corners are 0.00, and the forth corner is 0.01, so it’s as level as I could possibly get. The first layer extrusion also looks on the money from my experience.

Your idea of heat contraction sounds right as well, but that’s where I was stumped as to where to proceed. My thoughts are that if I could reduce the bed temperature that the heat contraction problem would go away. However, when I do that, adhesion also disappears causing a whole other problem.

What would be the purpose of the 6mm skirt? I understand that a 10mm brim would allow additional adhesion beyond the boundary of the part, but the 6mm skirt would just print disconnected from the part. Wondering how that would help.

I have had some success with rafts, however, it’s a pain to separate a large part from a raft.

I could also certainly increase the extrusion percentage on the first layer (I use simplify3D and it has all those options readily available).

The room it is in is quite warm and has no drafts, but have been thinking about building an enclosure for the printer. Perhaps I should do that sooner than later. Likely couldn’t hurt.

I’ll look at the temperature range for hips and see how much lower I could go.

The problem with lowering the bed temperature is that I find at lower temperatures the part simply pops off (likely related to the same reason that the part is lifting).

What I’ll try is the lower bed temperature, with the large brim and increase the first layer thickness and see where that takes me…

A skirt acts like a mini enclosure around a part. Its generally used on parts prone to splitting but it can help with lifting as well.

I always thought hips was a lower temperature plastic than abs. I haven’t played with it much either though.

Thanks for the info. I just checked the printing temperature range for the HIPS product I’m using and it states 220-260 degrees.

Use a 5-10mm brim. Helps to seal the project edge to the bed so air doesn’t seep in and contribute to the contraction from cooling.

Haven’t worked with HIPS, but turning off the fan for the first few layers help ABS. Usually, I leave the fan off for the first 4mm then set it to 30-50%… again for ABS, but may work for HIPS.

I never use a fan for abs except for bridging. You might try turning it off.

Yea, ABS = No Fan.

I would try a very tall skirt, and try to retain the bed heat around the part. I have used a 999 layer skirt before to print one a different X Idler part for a old R&D prototype machine I tried to refurbish a month or two ago. The skirt took the heat/cooling damage and let the part stay adhered to the bed. But I have a heated enclosure now, so no longer need to deal with cooling issues as much.

I print w/ABS, but not HIPS. I was having the same problem (corners and edges lifting off). The issue was with the fan - the fan seems like it was engaged quite a bit. Even with printing a brim, and keeping all the windows closed (it’s in a attic, so the space gets quite warm an there were no breezes on it), I was still getting curling. The solution was to completely turn off the fan (in Slicer). One I turned off the fan in the slicer settings/printer profile, I got much better prints.

Jeff

Thanks for all your comments.

Guess the consensus is that it’s a cooling retraction issue. I’ve been printing without the fan on, as I did find it was even worse with the fan.

Strange that I’m having such an issue as the room is dead calm and quite warm. Seems that I’m going to have to build some sort of enclosure for this if I’m to have any hopes of retraction-free prints eh!

Yes, I’d definitely recommend an enclosure if the other suggestions aren’t helping.

There are a few that work well for TAZ printers:

https://forum.lulzbot.com/t/hot-box-3dp-enclosure-system-for-taz/1283/1

and

https://ohai-kit.alephobjects.com/project/cat_guard/

Thanks for the links on the enclosure.

I’ve since tried a number of things (temporarily covering the printer while printing and cooling once completed), as well as printing a skirt the height of the part, and sadly cannot report any success.

The part still lifted terribly.

I’m baffled. Could it be that the heat is too high for the filament I’m printing.

I’m using eSun HIPS and Village Plastics HIPS, both that I’ve bought direct from Lulzbot. I’ve been keeping the print bed at 110 degrees and the fan off. I have found that if I drop the temperature a bit it seems to reduce the affect, however, then 9 times out of 10 the part comes loose before the print completes, and it’s ruined anyways.

Still completely baffled.

My ABS problem was helped by raising the head temperature and adding a enclosure, simply a thermal blanket draped over with a slot cut for the filament.

Honestly, if you’ve tried everything that everyone has suggested, there’s no reason that it shouldn’t work. So what you have to start looking at now is other things like, the filament. Have you tried a different brand of filament? You said you covered the printer, can you explain further, maybe it wasn’t covered well enough. What about the possibility that your bed is actually not getting up to the temperature that’s being reported by the thermister? Did you install the PEI yourself? if so how thick is it? if your piece of PEI is too thick it could be robbing some of the heat getting to the part. There’s no reason why you shouldn’t get this issue solved. I’ve been printing huge, thin walled parts in ABS, that take days to print wit,h no issues, the parts come out beautifully so we know it definitely can be done with the Taz printers. One thing that is a must though, is you need to keep the heat enclosed around the part, either using an enclosure that fits around the whole printer or by printing a skirt. Personally, I use the enclosure that I designed that fits over the whole printer and heats up using the heat generated by the bed, but you can use anything that will keep the environment around the part at about 35-50C. A cardboard box, thermal blanket (just don’t burn your house down) etc. etc.

Ok, thanks for all the comments. I’ve finally found a bit of time to try printing with my printer in a completely sealed box… What I did was use a Markor IKEA cabinet that’s in my office as the “hot box”. Granted, there’s no venting for the electronics, so by the end of this test, it’s going to be toasty, but this will prove once and for all (to me), if keeping the heat around the printer is going to prevent the warping/erosion of the corners of my print.

Here’s what the sealed package looks like. The cabinet is the right size for the printer, such that I can close the doors with the printer inside. I sealed the door with painters tape, so there’s no heat leaving the inside of the box as the printer chugs away. I’ve chosen for my test, a two piece Arduino box that I downloaded of Thingiverse. The one that I’ve printed to date with the printer in the open air did quite a bit of retraction at the corners resulting in not the prettiest part.

You’ll notice that I did not tape all the way around. The areas of the door that I did not tape are rather tight. I’m printing with Village Plastics 3mm white HIPS for this test. Still have an hour left on the print, then want to let it naturally cool in the box, so it’ll be a while yet before I can take a look at what printed. The anticipation is killing me… Heh.

As for some of the other questions…

  • I’ve tried three different manufactures of filament so far, and all produce similar results to date.
  • I’ve verified the heated bed is coming up to the correct temperature.
  • The PEI that’s on the borosilicate glass is factory from Lulzbot.

I’m hopeful, based on the comments, that this will solve the problems. I have to admit, my previous attempts to enclose the printer haven’t been very good. This attempt is definitely keeping the printer environment warm. If this works out, then the plan is to convert the cabinate into a permanent printer box. Was thinking I could use the existing doors, enhance the openings with seals and magnetic clasps, replace the center panels of the doors with lexan, add some electronics venting/cooling to the side and run some ports for the wiring to run in. Also have an accurate temperature sensor from Adafruit that I could use to build an arduino based temperature gauge… So, I do have plans for this if it DOES work. If it DOESN’T… Naw, I won’t even start thinking like that… :wink:

Will post my results as soon as the temperature has dropped to a suitable temperature. I was thinking of leaving it until it reached room temperature… I know lulzbot recommends removing the parts at 50 degrees… So far, I’ve always left them to cool to room temp…

Stay tuned… more to follow.

The parts are out, and the results are in, and they are…

Better, but not perfect!

I ended up getting zero warping, and considerably less retraction at the corners than I have ever experienced printing HIPS before.

I didn’t have the foresight to put a thermometer in the enclosure before printing, but while watching the temperature drop at the conclusion of the print, I noted that the temperature drop seemed to level out significantly around 63 degrees, inside the enclosure. Took quite a while to get down to 30 degrees, at which time I pulled the parts out.

So, as you can see from the photos, there is a slight amount of retraction on the corners… Looks more like erosion, but those points did lift ever so slightly. Like I said, there wasn’t much lifting but I won’t say that I’m not slightly disappointed. Was hoping for a perfect piece. Another thing I noticed, which has been common to everything I’ve printed on this printer, is that the first layers are flared out a bit, like the edge is flared out where it touched the printbed.

I think this test has proven that I need to move ahead and modify this cabinet such that it can be a permanent enclosure for my TAZ 5. Will have to also build another stand-alone enclosure for my TAZ35 at a later date. One at a time though.

Once I get this cabinet reconfigured for it’s new purpose, I’ll have to buy myself some ABS, and give that a try. Never printed with that. Only ever printed with HIPS and PLA. Wondering if this edge retraction is specific to HIPS. I’ve never experienced this with PLA before.

Here are some pictures of the finished printed piece printed in Village Plastic white HIPS. Hot end 240, Bed 110.

Overall, certainly a success, not perfect, but most certainly a huge step in the right direction.

I’m also printing with HIPS and have been having this same problem. I hope to be building an enclosure soon. In the meantime though, I’ve been experimenting with nozzle and bed temps and fan speed with little positive results. As it’s a cooling issue I would have expected these to have had more of an impact.

I’ve also found that not all of my corners are lifting. It tends to just be one, and not always the same side. For example in the picture below the front right corner lifted early on, effecting the rest of the layers to the point that the part is useless. the other 3 corners of the piece came out perfectly though.


After reading this thread I decided to try a make-shift partial enclosure with some foam board (seen below). This really does seem to have helped. I ended up with a little bit of lifting on the back right corner of a piece, but not nearly as bad. In both that instance, and the red piece above, the corner that lifted was also near the edge of the print bed, so I wonder how much of it could be that the extents of the bed probably aren’t retaining as consistent a temp as say the middle.

It’s also worth mentioning that I dropped my fan speed from a range of 40-50% on the red part to 30-40% to try and get the upper layers to cool a little slower. Not sure if that’s a correct strategy or not, but it seems like HIPS is similar to ABS, which from what I’ve read is best to use as little cooling as possible. Anyway, I printed several parts at once under this foam board “enclosure” and they came out pretty good. One of them was this Benchy print that aside from a few blemishes came out really well with no lifting.

I guess the moral of this story is that I agree, enclosures are good.

I would say the partial enclosure was a success if it fixed the oriiginal lifting of the front right. The reason the rear started lifting is because of the opening in the enclosure… heat not trapped. :slight_smile:

You’re on the right track to an enclosure. Just complete it. Foamboard or whatever. :slight_smile:

In the meantime, a greater surface area touching the print bed will help keep the corner from lifting. Try a 10mm brim… you’ll probably need to convert into perimeters so for an extrusion width of .5mm that would be 20 perimeters.

CWAVE6K, Hockey1237,

I’ve been having the exact same issues with HIPS (eSUN grey) (and ABS) as you guys have. It’s been very frustrating to say the least. I’ve tried just about every combination of fans speed, bed temps, extruder temps, brims, print speeds, and first layer thickness settings with no success. I guess building an enclosure is the next step. Frustrated that having an enclosure is not being pushed by Aleph or even mentioned in their HIPS/ABS print recommendations. Seems like as big of an issue as this is, they would have just built it with an enclosure to begin with. It looks like a lot of other 3D printer manufactures are already doing this.