Hi everyone,
FYI: I use a Makerbot Replicator 2.
So I ordered a roll of glow-in-the-dark PLA filament. I immediately had some difficulty setting it up right as the parts were stringing horribly. I finally got pretty decent results after I lowered the extruder temperature from 230 to 190 (!!) and fiddled a bit with the retraction settings.
I then changed filaments to a new roll of black PETG and again had a lot of trouble to find the right temp (this time 250). Now I just loaded the old roll of glow-in-the-dark PLA back into the printer to print another part at the original settings that used to get decent results. Suddenly, the prints are totally different?! As you can see in the pictures, the structure and color has changed. Furthermore, the wall thickness has increased with almost 0.5mm.
I have no idea what caused this, or how to fix it.
Any advice?
Here are some pictures:
On the left is an example of the result I got a few weeks back, on the right is what I get right now. (As you can see the stringing got back too…)
Same story here (although slightly different part):
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I also use Replicator 2s, and the pictures certainly look like it’s a temperature difference in the two parts. Your printer isn’t shared with other people who could have changed out the print nozzle, is it? I have 5 different Replicator 2s that are running different nozzle diameters and this sort of looks like the results when I use the wrong settings for a particular nozzle diameter. Also, are you running your machine on the Makerbot firmware or sailfish? I have all my printers running sailfish with great results, especially since I use Simplify 3D as the slicer. Another thought… was the temperature in the room where you were printing relatively the same on both prints? I can’t see that causing too much issue, but here in Texas the temperature can change 30 degrees over night and that certainly can cause various results.
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It sounds like a temperature issue. I have had issues with ambient temperature swings causing significant differences in print quality. Also if the cooling fan or temperature control components are failing, that can have an impact. Another potential issue, depending on where you live, is humidity. Plastics do absorb ambient moisture. Some plastics are much more susceptible than others. Most plastic injection molders make sure their plastic are dry before running it through the molding machines.
Cheers!
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Looks like water in the plastic tbh.
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My thoughts are this. PTFE tube? If so then over 230 and starting to ask for trouble. At 250 it is probably damaged.
Also if you ran PETG at 250 then went back to PLA at 200 or so you very well could have PETG still in the extruder since with the PLA temp it isn’t hot enough to melt it out.
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Thanks for your reply Jared.
I’m just running the Makerbot firmware and makerware for slicing. I have considered Simplify3D, but it’s just so expensive…
As I live in Holland in a pretty well insulated home, the temperature difference is at most 3-5 degrees.
I thought about maybe replacing the nozzle. This printer has run for almost 500 hours now, so it might need a replacement.
You’re very helpful, thank you for your reply.
The PTFE tube is fine, this doesn’t really come into contact with the heating block. Your other point does seem like a very likely cause. Any ideas on what be the best way would be to remove any leftover PETG?
Yeh I thought about that. Could definitely be as there’s a time difference of about 2-3 weeks between both prints. It’s plausible that the filament has absorbed water. I might try drying it out, thanks man!
Hi Acorn, thank you for your advice!
I just thought of something that may be of help to you. This may be hard to explain in writing… For years, I haven’t used the load and unload filament procedure that the Makerbot has. I found that in doing so, quite a bit of loaded filament remains in the nozzle and must get pushed out by the next filament that you load in. I was finding that even though the color eventually is clean looking, the leftover filament accumulates over time and starts to clog the nozzle. This is why many people start experiencing filament jams. Here’s how I always load and unload filament. Set your preheat temperature to around 180-190. Set your machine to start preheating. Once the machine reaches about 170 start manually pushing filament through the nozzle with your hand. If you have the newer style extruder with the spring loaded arm, press down on the arm while pushing the filament through. Sort of a side note, but notice the flow of plastic coming from your nozzle when pushing it through by hand. If the plastic flows straight down, it indicates a relatively clean nozzle. If the plastic sort of curves or curls a bit right out of the nozzle, it indicates a partial clog. As soon as you feel quite a bit of resistance pushing the filament, firmly and quickly reverse what you are doing and pull the filament out of the machine. You will find that this remove a lot of the old filament that was lining the inside of the nozzle. Now, loading the filament follows the same procedure. Simply straighten out the first several centimeters of filament as you normally would and manually push it into the machine all the way into the nozzle. You will notice the color change in your filament is almost instant with this method, and your prints should consistently be cleaner. Once you begin using this method, you should never have to change a nozzle because of print jams again. It never hurts to change nozzles, as they are crazy cheap though. I probably have about 20 nozzles in stock of various sizes just in case, but I find that I no longer need them. I’m interested in hearing your feedback once you try this procedure. The first time this is done, you may actually want to drop the preheat temperature to only 170 in order to remove the greatest amount of old filament. Once the junk is cleaned out, that preheat temp can stay at 190.
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I wasn’t sure about the PTFE but good to know.
On cleaning it out what I do is I have cleaning filament and I run it up good and hot (usually above the temp of the last filament used) and run one through before changing to another filament. For me it is mostly for color changes so like red doesn’t color yellow!
Risto_P
12
Hi
I do this too, it seems to be effective. If you search google for “cold pull 3d printer” or similar there are also some good instructions on that process described above. Here is one example with photos: http://bukobot.com/nozzle-cleaning
In the example they use nylon to do a really “deep clean” but if you do as DesignGuyJared explaines above then maybe you never have the situation that you really need the nylon. Just takes some experimenting to find the right “cold pull temperatures” for your different materials. Also if you do it to hot you can actually get more molten plastic stuck in your printers tubes…so start with relatively low temperatures I would say.
Good luck!
BR,
Risto
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ludozen
13
Thanks! I tried this a couple of times and at first I thought it was working. Unfortunately I still get the same results. Very frustrating. What botters me most is not the change in structure and color, but the change in width of the parts. Every wall becomes at least 0.7mm wider then what I had modelled. I think I will go ahead and order a new nozzle. Where do you order yours?
I order from ebay.com. I typically will buy them in multi-packs and usually try to get a variety of diameters. In the meantime, would you like to send me your STL file and let me slice it for you in Simplify 3D? All I would need to know is your extruder nozzle diameter. The standard Replicator 2 has a .4mm nozzle. I would really like to rule out the possibility of this being a software/slicer issue.
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ludozen
15
That’s very kind of you! I have attached the STL. This is a standard replicator, so the nozzle is probably .4mm then. I’ll take a look on ebay, thanks a bunch!
turfslurf_v6_p6_teststuk.stl (18.6 KB)
This system won’t let me upload an x3g file, so I’m sharing the file through this dropbox link. Let me know if you can’t get it, and I will come up with another way…
-Jared
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ludozen
17
Hi Jared,
Sadly to say, it wen’t horrible… The first layer did not stick properly and a bunch of plastic kept sticking to the nozzle. I then brought the build plate a little closer to the nozzle and tried again. But not much difference… I added some pictures.
I just ordered some stuff on ebay (for instance a ceramic insulation tape, which I did not have any more). Hopefully a new nozzle will fix the problem.
Hi , i did not read what others write , but same happened me .
i cleaned the hotend and the problem is past .
i clean now every time , when changing from filament .
i clean with pla natural , and cleaner filament about 5 to 10cm . at the temp what was last used .
i had this problem never again .
Oh , every spool has his own temp-setting so find out what best is.
kind like this : i do so , example pla bleu 200 degr. pusch by hand ,when flow easy by little force reduce temp , 195 degr ,
when flow is less but plastic is nice you done it good , same is for all other plastics , i have no problemms any more , never.
cheers Mike
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Wow! That was horrible! Haha… I’d say the new extruder should fix you up. Don’t forget to set your preheat to about 150 when changing that extruder. It will allow you to get the old one off and new one on without damaging anything. You may want to look up a detailed procedure on this. I was curious though… did you ever get any good prints with any other materials after it started getting bad results with the glow in the dark filament?
ludozen
20
Haha yes hopefully it will fix it. A good to know, I will look up a procedure just in case. I haven’t tried that yet. If I do, I’ll let you know ;).
