Solved Prints started failing

Hey all,

I got my printer this weekend and have been playing around with it. After my first successful print (spool holder with minor z ribbing.) I started a 9 hour print of a dice box. In the last 15-20 layers it just stopped. Fans kept spinning, matter control kept ticking, but the printer wasn't doing anything. I tried to trouble shoot it but ended up losing the print.

Every print I have tried since has failed, I've noticed crazy z ribbing (maybe?) and layers that just fall right off. at this point I'm at a loss of what to do, it doesn't seem consistent, sometimes test prints come out looking nice, then when I try a real object it fails miserably.

Some Info
-Printer: has cover on the bottom
-Material: PLA
-Temps: 205 hot end, 60 bed
-Speed: 30mm/sec
-Height: .2mm

Things I've tried:
-Extruder calibration: 150mm marked, 100mm extruded, ~50.3mm left (human error in measuring?)
-Checking play in z stepper, carriage, bolt (looked good)
-Checking bolts, belts, etc.
-Various temperatures and speeds

I'm currently printing the z resonance test, I'll add pictures when it's finished.

I've attached some images of my prints, the "L" shaped thing was a raiser, I printed 2, both failed and were completely different heights. The box was the second attempt at printing the dice box after a, seemingly, successful test print.

 

A little more information:

After the first 2 prints I connected the XXL LCD screen so I didn't have to be tethered to my computer. the raisers in the images above were the failed prints on the screen, I determined that the screen itself could be causing me issues.

I then removed the screen and followed the PDF and forums on z ribbing thinking it was my issue. Thinking I had the 5/16th z threaded bars and seeing alternate numbers .1905, and .2046 I tried printing the test prints in the PDF with both numbers. They appeared to have fixed my issue completely as I saw almost no z ribbing.

I then attempted to print the dice box in the image above with the .2046mm layer height.

::Sigh::

I'm half way through the z resonance test and it looks amazing... just perfect. If it goes all the way through without fail, I'll try printing the same dice box as above with the .2mm height and settings used for this test print (now that I know I have the 8mm z bars... right?).

Maybe I was changing too many things at once. these next 2 prints should clear some stuff up... Fingers crossed

EDIT: to clarify, the z resonance print IS using .2mm layer height. I found something in a forum somewhere that said if your printer had the cover on the bottom then it is using the 8mm z bars meaning I want to use whole numbers (.1, .2, .3, etc.)

 

Have you checked and tightened all the screws and bolts including the ones underneath the robo holding the stepper motors?
Have you seasoned the hotend and are you running an oiler?
These things will make a huge difference to your printing experience.

 

I've checked the bolts and screws, but I'll give it another once over. I haven't seasoned the hotend nor am I running an oiler (not sure what either of those are TBH).

So the z resonance test came out absolutely perfect making me think that maybe the issue was the weird layer height used on the box. I started the box last night with the same exact settings used for the resonance test. However.... I woke up this morning to an unfinished print. Matter control said that it had finished, and the box was stringy and already had layers not attached.

I'm really confused.... do you think it could be the model? I ran it through that Microsoft web service fixer thing just in case. I'll attach the .stl if anyone wants to test it, but I got it off of thingiverse where there were plenty of makes and the only modification I did was within matter control. I scaled it by 1.2 and tried to only print the main box part.

Why is it that my test/calibration prints are perfect, but I can't print anything else for the life of me?

 

That really does look like an issue seasoning and an oiler would fix. Your print speed should be fine, 30mm/sec. Like you I don't understand why your z test print worked flawlessly.

 

If it were failing consistently, I'd have something to go off of. I'll look into seasoning and an oiler for when I get home from work tonight and post my results. I also have a friend I may ask to print that dice box just to eliminate the possibility of the model being wonky.

 

If it makes you feel any better that Z resonance test came out way better than the one off work's Makerbot 2x

 

Ha! Well if I can dial it down to consistently print like that I'll be happy

About the seasoning/oiler, does that involve just dipping the filament in canola oil before feeding into the extruder, or is there more to it? From what I've found, too much will just leak and some people have found success in putting a few drops in those filament duster things every few prints.

It looks like other full metal hot ends have also had issues printing in PLA and this has fixed it, so I'm excited to try it out (mostly because it's extremely cheap and easy). If this is the issue it makes sense that it has progressively failed worse and worse the more I printed.

 

You'd be surprised how many printing errors are actually caused my model geometry or slicing issues. Seems to be the majority of failures once you get consistent filament flow. Even my MakerBot has a huge scrap pile from issues just like you're having. Filament oiler helped a TON for both printers.

You definitely don't want to over do it with the oil, but even if you do I haven't noticed a huge downside except for oil on my glass.

 

Awesome. Time to watch the clock until works up, thanks for the help I'll report back later this evening or tomorrow morning

 

So, I "seasoned" the hot end, and began the dice box print keeping all settings the same. I'm simulating an oiling setup with a q-tip that has a very light almost dry amount of oil on it. So far the first ~20 layers are looking good, I'll keep an eye on it and post an image when it's done in about 3 hours or so.

As of right now I'm extremely optimistic

 

What does the oiler do to improve the print? Does oiling leave an oily finish?

 

So the best way I can explain it is this:

PLA is a sugar based plastic, when coupled with an all metal hot end there can be issues. what happens when you try to bake on bare metal? it sticks. how do you fix that? oil. so the oil lubricates the hot end to prevent the PLA from thickening/sticking and clogging.

If you look at my third post at the attached picture of the dice box you'll see that layers are all over the place and not sticking together, as far as I can tell from my past few fails and this print with the oil, the filament was coming out at different thicknesses throughout the print. The oil cleaned it up so it comes out uniformly.

 

Success! Haha perfect, I can't believe that a little canola oil completely turned around these prints. Attached is the completed dice box that had been failing above. I'll mark the thread as resolved, and keep on printing.

Thanks guys I appreciate the help

 

Nice print. Now you get to work on reducing the z ribbing. There's always something to upgrade or improve lol.
An oiler tends to be the silver bullet for PLA printing issues. Great job.

 

Yeah, I have some bearings on order and z stabalizers about to print, hopefully that will clean it up. at this point I'm just glad I can get things to print at all, means I can keep printing upgrades and tool holder/organizers

 

Glad to see you got it working. Does your printer have a cover on the bottom and smooth rods that run to the top? Might not need the stabalizers

 

I have the cover on the bottom, but the smooth rods don't connect to the top. I really wish they had versioning with documentation so we can know exactly what changes are in the printer. I'm still not 100% sure I have the m8 threaded rods or the 5/16th.

Either way, the bearing fix should significantly reduce the "waves"

Honestly... I'm becoming more and more interested in building a Kossel style printer. Something like this kit. But I can't justify buying another printer. So unless I can convince a friend to buy this off of me I'll continue to make it better in whatever way I can.

 

Bearing on the threaded rods is a bad idea. Can you take some pictures of your printer? It's strange to me that you have a bottom cover and not the smooth rods.