oloand
April 4, 2016, 10:12am
11
Measure the diameter of the filament (at various positions) and check that the diameter does not vary over the length of the filament and conforms with the specification.
I have some green filament that does that. It may just be down to the quality of the filament. Is it from the same supplier/manufacturer? You could try different temperatures. Also check the diameter with a micrometer. The green I have is only 2.85mm not 3mm so I need different settings in Slic3r.
Good luck.
I have had something similar on one of my printers (Prusa i3): Possibly that the filament is more or less brittle and is being eaten up in your extruder and then ‘under extruding’ for some parts, may be happening more as it gets faster on long stretches… Increasing the temperature may temporarily seem to resolve the problem (or it could actually need a higher temperature to run on?) Have you used this filament before? If it’s being eaten up from the extruder (you may see chunks taken out of the filament as it goes past the hobbed gear - try stopping your print as it’s failing and backing up the filament 50mm to check) then you can try increasing the spring force on the extruder and also check the sharpness on the hobbed bolt or whatever hobbed gear you are using. As they wear out, they won’t be able to push with as much force and do more ‘rubbing’ plastic off. Although tuning those things is a good idea, it wasn’t the real reason for my problem, for me it was to do with a new hotend that I installed that is having trouble extruding at the same amount of pressure as my previous hotend and required more force from the extruder. I was using a hobbed stainless steel bolt that is quite old, so I got a new one from Mitre5 and printed a hobbed bolt making tool for a dremel (out of black PLA - Thing # 23717) and it’s been a huge improvement although still not able to reliably print white for hours on end. Slowing down the speed could reduce the issue but not really a solution…
Black filament is much easier to extrude out of the hotend (In my experience) as it’s usually made with multiple dyes at the end of a filament run and then black is added (so the manufacturer would combine all the left over bits of other colour filaments into another batch, add some black dye to it and call it ‘black’) and it becomes a bit more soft and easier to extrude as a result, white filament seems the opposite and is more brittle for me. This depends on the filament manufacture, filament is certainly not created equal. I live in a dry climate and don’t get any moisture problems so can’t really comment about moisture.
So the rule here is that different filaments have different printing characteristics. Even though they are all ‘PLA’ they may have different temperatures and force required to push them out of a hotend. I spent a month messing around until I was certain this was a hotend issue and not my filament. For you however, it doesn’t mean at all that it’s a hotend issue, but more investigation is required.
it is underextruded try set flow by 20% or rise temp by 5 until ok ,if not working, let it cool down on 130 release filament cut and insert it again
are you at the end of the spool? some printer have difficulty to pull the filament if the spool center is to small.
Hi,
what’s your extruder’s temperature?
You might be looking at a partially clogged nozzle? I’ve had the same in the past, the PLA is then burnt inside the nozzle & is *partially* blocking flow.
Strangely, blue PLA was giving me more frequent blocked nozzles than - for example red or white PLA did…
Let me know, if you need more details.
At what speed and temperature you print?
1 Like
I have the same with Bleu and on forums u see a lot of problems with this collor
Haydn
April 4, 2016, 11:43am
21
Hi all, thanks for the replies.
To answer all questions : Temp filament PLA 215c. Bed 65c.Speed 50.
roko11
April 4, 2016, 11:47am
22
Does the blue feed correctly through your extruder? Might require some temp/pressure or other tuning. Is it a different brand of filament. I have found differences between settings needed for different filament brands and even different colors of the same brand.
It might be old blue filament and having absorbed humidity
215c is commonly too high for PLA. You usually want to be printing between 180-205. My thought is that your hotend is heating up the PLA too much and the heat is rising up through the shaft of the hotend. You can try two things… Print at around 200c. Add a fan to blow at your hotend on the cooling fins. Look up E3D hotend if you don’t know what I’m talking about.
How to Find the Perfect Print Settings For Your 3D Printer - YouTube Watch this video on how to calibrate your temperature and flowrate settings. The blue filament may need different settings than your other filaments.
sherif
April 4, 2016, 2:07pm
27
do you have the correct nozzle diameter set?
SOC3D
April 4, 2016, 6:30pm
29
Haydn,
There is a lot of good information here and hopefully it helps you out. Could you tell us if the three colors of filament you are using are the same brand and grade? Were they purchased at the same time? Were they opened at the same time?
Also you mentioned that the issue didn’t occur with the blue until the middle of the roll, was there a period of storage where you were not using the roll for a period of time after which the issue started?
Try to don’t heat bed, blow on your bed and lower temp (195/205°c). I succeed with PLA since I put a computer fan front my bed and dont use heating bed. Use brim and spray.
