PLA warping - Even with Buildtak!

Hello Reprap,

I have 2 printers, an I3 and a Smartrapcore.
The smartrapcore has a build size of 30cm x 30 cm x 30 cm And has buildtak installed.

The I3 has a heated steel plate as build plate.

When i try to print PLA, it warps in the cornors. This happends on both of them.

I tried different temperatures (190 - 220 degrees), with and without active cooling and i even tried heating the heated bed to about 65 degrees on the i3 (all steel)
I tried using PVA Glue to help sticking to the steel plate, and this didnt even help.

And on the smartrapcore, it just doesnt adhere in the corners. The rest of the print sticks like a charm, but the corners have a tendency to warp, no matter what settings i use.
Also tried the same range of temperatures as on the i3, and with and without active cooling.

Any suggestions to what might be the issue?

Is the hardware and software properly calibrated?

I would say so, yes.

the prints come out with a very nice surface, and the first layer looks very good. Its a little squished, but not so much that small pikes appear on overlaps.

but which calibration factores would you advice me to look at?

Edited 1 time(s). Last edit at 12/26/2015 11:51AM by Kafledelius.

PLA is weird - it seems to be a very small difference between not sticking at all and being next to impossible to get off. Blue painters tape really does work well with it, but it's a pain because I was always damaging the tape trying to get the print off. My guess is that you can find the magic sweet spot if you keep working at it, but I prefer printing on glass with Elmers purple glue stick as it's just less hassle. Works great with PLA, nylon and PETG. I go for a fair bit of squish on the first layer and print it really slow - 15 mm/s

Edited 1 time(s). Last edit at 12/26/2015 03:49PM by JamesK.

I mean the basic calibration of motor steps and bed for example.
If the machine is not setup properly you might be trying to compensate for a problem that otherwise would not exist.

I really find it weird, since the majority of the build is so stuck, that i have to use a great deal of force to get it off :s

I also print the first layer really slow (10-15mm/s) and i even use a layer width of 150%..

Try 200 % first layer extrusion width. Go even higher until the print looks terrible. Otherwise, I'm stumped. Do you have any pictures of the prints that warped?

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Master Tinkerer

Thank you for your Response Montiey.

I'll try and take some pictures in the morning.

I tried the bigger extrusion width, with no result

How ever, it seems that my ABL is not correcting enough on 1 side. (Same no matter what way i turn the build plate, so its not due to differences on the buildplate).

So i'm going to try to design some new feet for it, see if that helps.

But i doubt this will fix the adhesion issue since the first layer looks really good (even though the ABL has an issue)



- Another update!

I found out that my current cable arangement affects the hot end when it moves. The cables pull on the hotend, in such way that the distance and angle to the bed changes.
My cable spans over an area of 30x30 on my smartcore. Does anyone have any idea on how to fix this? one that doesnt mean cable chains and having to increase the length of every wire?

Edited 1 time(s). Last edit at 12/27/2015 02:50PM by Kafledelius.

Fantastic work, detective.
If the cable is too short and pulling on the extruder / hotend, then you will definitely need to either extend the wires or pull some slack up to give it some more room.

Note for future reference: This same thing will happen with the filament if you are using a direct drive extruder and overhead spools. I have used a bowden tube that basically lets me put the entrance point anywhere, and the tension to the extruder doesn't pull the whole thing tight at all. It seems to work very well. If you don't use something like that, you should at least put adapters in the spool hubs so the friction is reduced.

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Master Tinkerer

Well, actually Its the Weight of the cable.. I might have found a solution for that issue..

However, im still facing a but load of warping on my buildtak plate im close to throwing it out and simple print on pva Glue.....

Hmmm, that is about what I did to my buildtak...
You really need to get all parameters right to get the correct level of stickiness or you can choose between the part lifting off or using serious hand tools to get it off.
Everything I print goes on a cold glass plate with some craft glue on it and I have little to no hassles at all, even Nylon prints well.
No gimmicks, no heated bed, no fans to cool the print, just proper print settings....

Thats just about what i'm leaning towards doing!!!!
A damn buildtak sheet for 300mm x 300mm is pricy enough! And it does not live up to the expectations of the product description!

- I've done the same on my I3, which prints beautifully now. This has a heated bed though, and increasing the temp to about 55-65 degrees really does wonders..

Though i havent managed to solve the abl issue
For some reason, one of my corners is over compensated
One corner is a bit higher than the rest, but ABL is compensating Way to much!

Quote
Downunder35m
No gimmicks, no heated bed, no fans to cool the print, just proper print settings....

No bed heat, no fans is pretty hard core. I'm leaning hard on both to make my life easier I do like the sound of ABS popping off the glass as the bed cools, so much easier than the fight I had with my first prints with PLA on blue tape! They were murder to get off.

Just an update.

I decided to Give buildtak a second chance.
The print was done with the following settings:

First layer width: 150%
Nozzle temperature: 220 Degrees (for the first 3 layers) then 200 Degrees.
Layer height: 0.2mm
Default printing speed: 100mm/s
First layer speed: 15%
infill: 40%
No cooling for the first 5 layers.

And here are some pictures of the first layer and some of the end result......
Does this give anyone an idea towards what could be happening?

That's PLA? I've never seen mine do anything like that. Perhaps it's a bad batch. Great colour though!

A couple things..
Try disabling cooling all together, and try reducing the print speed to something lower than ~60 mm/s. Then, crank the temp for the first 20 layers or so to something WAY higher than what a sane person would use ( > 225°). I'm curious if your hotend is not heating to the proper temperature, causing a cold layer.
Other than that, your first layer looks pretty good.
Try using painters tape. This isn't something that looks like an extrusion issue to me, so it must be purely to do with the plastic sticking to the bed.
Good luck!

P.S
Is it possible that your filament is actually ABS? This would explain the cold layers. You may want to try different filaments just to eliminate any quality issues as suggested above.

Edited 2 time(s). Last edit at 01/01/2016 06:45PM by Montiey.

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Master Tinkerer

Thank you for your answers!

I have actually tried that already.
I have switched filament another batch, color and so On.

I have Also tried temperatures all The Way up to 235 degrees..
Also tried The slower printing speed.

How ever, This batch of pla States temperatures from 190 to 240.... Which seems OFF to me :/

Oh and also, The parts Are very strong, No delamination or Anything.

I just checked The thermistor settings. Its set for The semtec (5) in marlin, and i an ising The e3d V6, so that seems to be fine.

Edited 2 time(s). Last edit at 01/01/2016 07:06PM by Kafledelius.

Hmm..

I currently have no logical explanation for why the print is delaminating. There are only so many variables that can be changed..
Do you have PID enabled for the bed?
Have you tried printing with the bed off?

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Master Tinkerer

Have you tried another batch of PLA?

One thought I had when I first started reading this thread was possibly cheap PLA, try another (reputable) vender.

There is No heated bed for that printer.

I have also tried ising Colorfabb, Which Wasnt Any better.

And i dont get Any delamination. All layers Are very strong..

Its simply The first layer that wont Stick

Edited 1 time(s). Last edit at 01/01/2016 07:51PM by Kafledelius.

I looked your latest photos. Wow that's a lot of warping.

I have a few thoughts.

1) I think you need to eliminate the possibility that the Buildtak is the problem. Can you just use some blue painter's tape (or even wide masking tape) over it? Others have suggested this. Will tape stick to the Buildtak? I don't have any experience with it.

2) Have you tried cleaning the Buildtak really well per manufacturer's specs? Perhaps there is a tiny amount of oil.

At my makerspace they have a bunch of printers that print PLA, and still have a lot of problems with warpage, a lot more than I thought they would. They print on the blue tape or just masking tape, and it doesn't warp off the tape, it pulls the tape up... I think their problem is the A/C in the room is blowing on the printers. So finally:

3) Is the area where the printer is cold or drafty? If so, can you put something like a plastic bag over it to keep the drafts off and a little heat in?

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My printer: Raptosaur - Large Format Delta - [www.paulwanamaker.wordpress.com]
Can you answer questions about Calibration, Printing issues, Mechanics? Write it up and improve the Wiki!

Hello Paul!

Thank you for your response.

1) I have tried printing directly on steel with PVA glue, with the same results.
2) Yes, i'm cleaning the buildtak with isopropyl alcohol.
3) I'm trying this now! As it is actually placed in my garage. Its heated though, to around 22 degrees. but the heat is a heat pump, which might apply some draft?

It seems you tried almost anything but with no usable results.
On the other hand I print on a cold glass plate with no problems.
So let's start from the beginning, waste a bit of filament and see if there is an improvement:
1. take a simple test cube of 25x25mm and about 10mm high.
2. slice it with these base settings:
(assuming your printbed is flat and all is calibrated properly)
First layer speed: 15mm/s, 120% extrusion width, brim of 10mm, layer height 0.1mm.
Temperature for the first layer 210°C, no heat on the bed.
Other layers @ 0.2mm, 195°C, 30mm/s and with solid infill every layer set to 1.
Use painters tape on the bed that you first slightly wet with alcohol and then sand lightly with 150 - 200 grid sandpaper.

The above should work in any case unless you extrusion and first layer are really badly calibrated.
Although PLA should work without a brim I suggest to use this quite wide brim to ensure the cube itself has something to hold on when it wants to peel.
Same for the thin first layer, it gives the hot plastic more force to bond with the surface and due to the alcohol and sanding there should be a lot of fibres sticking up to hold on to.
The solid infill is to make sure you can check your extrusion calibration as here every bit too much will cause a mess sooner or later.
The print speed settings should be the same for all, same for the extrusion width - set it all to the same value.
So you print with the same speed and extrusion width for all part of the print except the first layer.
No retraction at all!
These last bits will make sure you have the pressure in the nozzle as constant as possible throughout the print which should rule out any problems with extruder or hotend / nozzle.

If this fails as well I suggest to do the entire hardware, bed, first layer and extrusion calibration from scratch as something must be wrong somewhere.

120% first layer I guess would be okay, but I use 180% just because having it thick does the same as having the whole layer too thin and smushed, but makes things look cleaner.

Next, does buildtak require a heated bed? I'm sure it could work without it, but that could be the root of your problems. Then again, if things didn't work with painters tape.. A heated bed will always help, especially if you want to print anything but PLA in the future.

Edited 3 time(s). Last edit at 01/02/2016 09:31AM by Montiey.

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Master Tinkerer

I already ordered a heated bed for it.

But yea, the buildtak should work flawlessly with a cold bed.

However, i've done the test calibrations, even temperature calibrations, and small cubes seems to stick perfect.
A 3DBenchy boat only slightly warps towards the stern of the boat.

God i hate 3d printers right now :'(

Some guy i know told me to try and sand the buildtak slightly, and add some hairspray to it.Guess i'll have to give that a go.

Is it possible that the tissue or cloth with which you wipe the build surface is the problem? I discovered some years ago that high strength kitchen tissues had something that dissolved in acetone and stopped ABS from sticking to glass or kapton.
Mike.

could be... I'll try using a regular cloth

The sanding and hair spray did nothing......... :'(
'

As a side note.

I've noticed that when i turn the fan on, my hot end can't keep temperatures higher than roughly 207-210 degrees.

Could this have something to do with it? Maybe the hotend cant provide enough energi?

Edited 1 time(s). Last edit at 01/03/2016 08:57AM by Kafledelius.

So the issue has been resolved...
It all came down to the heater catridge.
I swapped it for a new 40W heater, which changed everything. Now the plastic has a different molten look when extruded on the first layer, and it even smells like melted pla now (Which i didnt quite get from the hotend before).
I'm now printing even colder than ever, and getting way better results.

So if your experiencing the same thing! Examine your heater!

Mine seemed flawless. It had the correct resistance and current running through it. But i guess the power just wasnt high enough?


WHO CARES!!! IT WOOOOORKS!!!!!
Victory pics attatched....

So, too cold? I guess that was right.

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Master Tinkerer