Problems With Layer Seperation/Curling in PLA

Hello everyone, so I'm trying to print a 20mm x 20mm Test cube in PLA, here are my final settings 'http://gyazo.com/6c757469c9176dae8a5b5bed812bc0bd'. I have tried lowering the print speed, it was originally 50mm/s and it improved a little but not as much as i hoped for. I don't know why this is happening, what is it even called, i cant find it anywhere! (See Gyazo link at bottom for image). The top is also really crap, ho do i fix this? I've tried mounting a nozzle (https://www.thingiverse.com/thing:839620) fan but that doesn't help at all. Changing the flow rate dosen't do much either, the motor just begins to chugg, even at around 100% flow rate. See video link below) If anyone has any idea to fix these issues, pls

Layers:
Image 1: [gyazo.com]
Image 2: [gyazo.com]
Image 3: [gyazo.com]

Top Of Cube:
Image 1: [gyazo.com]

Nozzle Fan:
Image 1: [gyazo.com]

Top Of Cube:
Image 1: [gyazo.com]

Chugging: [www.youtube.com]

Edited 1 time(s). Last edit at 07/27/2015 04:00PM by 32bitbrad.

Well, I can't tell you do x, y and z then your issue will be fixed; however, I can tell you where I would start. I think the most important thing to note is that the defect has a pattern to it. That means that every occurrence of x or every time period of y minutes the same thing happens. You can use this as clues to help you figure out the issue.

I've never used a direct drive bowden (that's what you call what is feeding your filament right), but I have spent some time considering them. I noticed your PTFE tube looks to be hooked around the end of your controller there. Could it be that when your x carriage is past center to the left the controller is bending the feed tube too much causing the feed issues? If the teeth of the feed gear are stripping the filament, this might be a sign of that.

You might check your hot end temperature to make sure it's the right value for the type of plastic you are extruding. You could even take this a step further and get one of those cheap temperature lasers and shine it right on the tip of the hot end. I found a defective thermistor this way. It was still functioning in away so I was getting bad temp readings. Wish it would have just not read anything at all. That would have been much easier to diagnose.

The top of your cube is suffering from the same issue as the sides. Some kind of filament feed issue. Once you get this feed issue worked out don't be disappointed when your tops still don't come out right. Bridging is a whole other beast. Get non bridged prints working first and then tweak things to get bridging working.

Have you done that basic test of marking the filament 30mm from were it disappears into the extruder, tell the printer to extrude 30mm of filament, and watch to verify the mark moves right to the edge of the extruder? If not, that one is a good one to do. If you haven't done so already, you might take the time to go through one of the configuration guides on this site. I am partial to Triffid's guide.

Edited 1 time(s). Last edit at 07/27/2015 04:16PM by appdev007.

Hey, thanks for the detailed reply. I just tried a high temp of 205C, and the print was miles better! The chugging is now also very minimal. However i can seam to get my printer working with Repeiter at all to do that extruder test, i know about the recant FTDI Driver Gate thingy and my chips are not bricked, i have updated the drivers to 2.10.0 and i still cant get Repeiter to talk to it? I have a thread here 'http://forums.reprap.org/read.php?406,536483'

You'll want to be sure what the source of the temperature issue was. You'll have a hard time getting good prints if you don't have your temperature lined out. I've had PLA that prints from 180 to 195. All of my ABS has been above 200. I don't know what filament you have, but I have found that each brand has it's own properties, including how well it flows at different temperatures. I got one roll of ABS that would flow out on to the part well at my standard ABS temperature, would flow to much if I raised it, and wouldn't stick to it's self it I lowered it. I quit trying to print with it after experimenting with half of the roll. It now sits under the bench for when I need a bit of scrap round plastic about 3mm in size.

I just use the filament that came with my printer, Unbranded 1.75mm PLA. Im doing another print right now just to make sure temp was the issue. I'm then going to lower the feed rate and re-increase the speed to try and get the most efficient and optimal settings. Once i've depleted this roll of PLa. ima gonna try the ABS i also got. I'm printing in my bed room though and I've heard it smells really bad and the fumes are toxic? Do u know of a way i can stop myself from choking in my sleep? XD Many thanks!

Yes, I have heard you don't want to breath it either. You can put your printer in a box and vent it outside, but when printing ABS I have found that you have to be careful about how much air you have moving. I have my fan set to only come on when printing in the smallest of area. I would recommend holding off on the ABS. It has complications of it's own. Get PLA working well first. If you can afford it, drop the dough on a roll of Ultimachine PLA to get your printer dialed in. I've never had a bad roll of it and it seems to work how people around here think filament should. If you really can't afford that then the last thing I tired was the hatchbox black PLA off of amazon. Without doing any tweaking my prints came out looking almost as good as they did with more expensive brands and the stuff stuck to it's self. I ran it at 191 degrees. That said I really really recommend not skimping on filament when trying to dial your printer in for the first time. You have enough issues working against you when going at it your first time. Why not eliminate as many of them as you can.

Welcome to 3D printing. It's not like running an inject printer. Once you get the machine working you've only made it a third of the way through the battle. After that you have to learn the plastic.

Here is one more tip. I recommend printing on glass with both types of plastic. I recommend cleaning the glass with isotropically alcohol (NOT RUBBING) before each print. Oil on the glass is not your friend, this includes oil from your fingers. For PLA apply a couple thin coats of extra hold hair spray allowing each one to try between coats. A fan or you bed heater can help with this. I don't recommend spraying the glass while on the bed as over spray can get on your printer. For ABS I recommend glue stick. Again apply a thin coat, slightly over lap the strokes, wait for it to dry, and then apply another coat in the opposite direction. You can clean the glass just by running it under hot tap watter using your finger to remove any though spots. You really can get a way with re-coating to do another print, but I really recommended cleaning the glass between every print when your first starting out starting out. These bed treatments work for me 99.9 percent of the time and in case of failures it's mostly been my fault for being lazy. As a matter of a fact parts stick so well I can't get them off. When this happens, just take of the glass and stick it in the freezer for a few minutes. When you take it out the parts will fall off.

Thanks for the Tips! I'm waiting on some ESun PLA Filament to come back instock at www.hobbyking.com, I've heard its actually really decant, cheap as chips too! I'm using a heated aluminium bed, with a painter's tape protecting it. I use some hair spray before each print to ensure it sticks. We dont have that Aqua Net stuff in the UK. (It is water based right?) So i'm looking for another water biased brand i can use. Right now I'm just using cheapo Hair spray from the discount store, does the Job. I also change the tape after every coupe of prints.

I'm only 16 so I cant really afford more expensive filaments with a Saturday job wage, I'll defiantly give that Hatchbox a go tho thanks! Can you recommend any other cheaper filaments?

What does having a fan on the nozzle do exactly and what does it help to do? Bridging I'm guessing?

Thanks!

It can indeed help with bridging however you are supposed to have one blowing on the top of the hot end at all times when printing PLA. If you don't it can cause your nozzle to jam. Now I'm speaking about the use of a jhead hot end, but i think it holds true for almost all models.

You should have one blowing on the work almost the whole time you're printing PLA to help avoid curling. If you don't cool PLA quickly it will can defourm. I have also found that it helps when printing abs in small areas. For example like when you're printing a five millimeter vertical shaft things will just be too hot and the ABS won't lay down right however if you have it blowing when printing in larger areas of abs it can cause issues.

Edited 1 time(s). Last edit at 07/28/2015 08:29AM by appdev007.

Oh ok, so i guess printing that fan duct was a good move then. I've printed out parts for a dual fan kit on the hot end (One for the heat sink and one for the nozzle 'http://www.thingiverse.com/thing:891623') Just waiting on the blower fan to arrive from china . Printing ABS in my bedroom is a bit like suicide right now, we're having the boiler moved out of my room in a month or two, so i can use the outside vent from where the boiler was and modify it into a duct for fumes i guess? Will that work? Again, thanks for all the tips, I'm writing them down in a word doc as we speak!

An old laptop is a good source for a squirrel cage style blower fan.

That's a stroke of luck, I'd have to pay to have a vent hole put in my room!

Like I said, just watch how much air you get moving around the printed part. You don't want very much with ABS. I haven't done this yet to speak from experience, but you might want to think about putting a double shell around the printer. One around the printer its self to block air movement, maybe with a lot of small vent holes in it and a second larger one with the printer sitting it it hooked up to the vent duct with a small opening to the room to take air in from. You might even be able to put two smaller pipes in your boiler vent. Have one pointing down to take in air and a second pointing up (put a cap on the top to block rain) with an extension on it to vent air. That way you wouldn't have to suck air out of your house.

Also keep in mind that once you start enclosing the printer you have to be aware of heat build up and how that will effect your electronics and motors. You could mount the controller board outside the inner enclosure to make sure it doesn't get too hot, but the motors will still be inside.

I hear ABS likes a heated chamber though. Guess it allows for slower cooling.

Edited 1 time(s). Last edit at 07/28/2015 11:45AM by appdev007.

My bedroom is not that large (Not anymore anyways) Half my room is stacked with tech and gadgets, how large and how difficult do you think this enclosure would need to be? And of course how much do think I'd need to spend on building it?

I'll defiantly use that 2 pipe idea England is cold (and wet) though, so perhaps bringing in air from outside could lower the box's temp too much. Maybe bring in the air from my room through a carbon filter, than out of my room from the boiler vent. I could also build an automatic temperature controller air flow thingy to regulate the temperature?

I'll look on YouTube for some build ideas, for now, I'll stick to PLA. At least my room sort of smells like Rainbow Drops now

Thanks

Yes, youtube is probably a good place to look and search the form for enclosure. I wouldn't imagine you would have to have something larger than a few cm larger than the printer its self if you were going to do a single enclosure. I like the "automatic temperature controller air flow thingy". Be sure to name it that when you publish the object files and the source code. ; )

I'm thinking the ABS won't have issue with it getting to hot. From what I've read it would likes the whole print area rather warm, but I would read up on that. However, the controller could be used to switch from inside to outside air when outside conditions were right.

You hit on something I didn't think of, besides the outside air temp, and that's humidity. Besides cold air, introducing extra humidity from the outside probably wouldn't be good either, so the inside air would probably be a better idea. Well that is if you guys across the pond have air conditioning! ; P

We don't need air conditioning, opening a windows does the job over here! XD (Not for too long though, you'll get frost bite) Anyways, if i do get round to making it I'll send u a link and i will name it that, its catchy! (I'm a genius )

Do you think I'd need an auxiliary heating source to heat the air, or would the heated bed do the job for me? It's always raining here, it is now actually... so bringing in outside air is a bit risky like u said. Perhaps i could use some sort of filter thing, like an absorbent thing to minimize the water content the air?

Cheers!

I'll be looking for that link. ; )


I don't know, running a heater to heat the outside air might cost more than just letting it take a little of the air you already paid to heat up in bulk from the inside your house. You only need enough airflow to keep things going to the outside. You shouldn't need a super fan or anything. Theres another idea, put in an air flow sensor to that triggers an alarm when air isn't flowing to the outside anymore.

Thanks a good idea actually, but saying that I'm no Arduino programmer or anything. Guess I'll need to learn!

Do you think a 120mm PC fan will do, one pulling in and one pulling out, use some some of voltage regulation to automate air flow?