Noob tips for Noobs

Ive had my printer less than two weeks and have been having great success with my prints, so I figured I would share some tips. I found a lot of info on here, and then some stuff was just not out there. Do these things and you will be printing without a doubt.

Things you need to do:
Lubricate your Z screws (the tall screws going straight up). I tried dri-lube, but it didn't last long. I used a thin layer of black grease and its been going probably 30 hours with no problem. If you don't do this...you will get crazy squealing and vibration, and then the nuts will come loose when it binds up.

Bed leveling. The stock set up is very hard to adjust. What I did was left the front two standoff assemblies alone, and modified the rear. I removed center nut and replaced with a rubber o-ring and washer. They were nearly the exact same size as the nut, only slightly taller which is good. Then I flipped bolt so the nut was on top. Tighten the nut to lower the bed, very precise, very fast. The bolt is 3mm, so get 3mm washers, they are typically 1mm tall. The rubber oring is just big enough to slip over the 3mm bolt.

Bed flatness. My glass was bowl shaped, as they all are Im sure. Take a straight edge and see how flat is is. You can get it flatter by tightening the belt connected to the bed. Mine sounds like a guitar string, but doesn't hinder movement. This will make huge difference in printing, and HUGE different in getting first layer done.

Extruder height. I went around and around with this, since I had zero 3d printing experience. They say around the thickness of a business card, I say that wont work reliably. I set mine so close you can barely see daylight under it. I make sure it will not hit anywhere and is uniform as possible around bed.

Getting prints to stick. Glass is decent, some people use hair spray, glue sticks, etc. The best method that seems to work forever is a sheet of vinyl from any sign shop....sticks awesome, cheap, and clean. I have not tested with ABS yet.

Next thing is to set your first layer height to .3. This is very important. Then set skirt "loops" to 2 on bigger models or 3 on smaller. You want to get temps stabilized, and the filament flowing good. Also shows how your print is going to stick. I have printed PLA from 190 to 210c, all printed well. Have a part that warped? Try adding "brim" to it, this will help tremendously. Try 5mm.

If you do all of that, you should have it pretty easy. I went from setting z height several times per print...to now I don't touch the machine, I just hit print. One thing that will help reliability is the XXL LCD screen, because you no longer have to worry about PC going to sleep, usb issues, etc. I bought mine from printed solid on here, and love it. This printer will do some amazing quality prints in stock form, don't get caught up in the upgrade game thinking your prints will be better. If your stuff is right, its going to be awesome either way. New parts aren't going to make things better.

 

This is great to know. I like the "don't get caught upgrade game" comment.




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Yes i see a lot of guys doing upgrades and not getting good prints yet. Get dialed in first....chances are you will be very happy with results.

 

Great write up

 

For sticking ABS to the glass I found that a layer or two of glue-stick glue works a treat. I have tried two different brands but the yellow UHU glue-stick (the one that doesn't say it's non-toxic) seems to work perfectly. I warm the bed up to 50c, place a layer or two on the glass, then continue the heating ready for printing.

Also, I cannot stress enough to watch the first layer being put down and manually adjust the Z height to make sure that it is printing properly. Remember that setting the Z axis stop screw will only be as accurate as the switch wants to be at the time, so manually adjusting the height on that first layer of each print is important.

One other thing I will mention, I agree not to get stuck on upgrades but for ABS you MUST look at fixing the polyswitch issue either by replacing the fuse or by printing the MOAB brackets and placing a fan on there (or the new bracket that Robo3D has released). Without this a lot of people have found that the bed temps die half way into the print and come un-stuck.

 

Ive printed more than a 1kg of PLA (Black, White and Red) and been having great success. Printing on blue tape with either Cura or Repetier.
I finally decided I knew enough to give ABS a go. I stripped off the blue tape and applied some UHU glue stick and was impressed with the results. Started with the 5 mm pyramid and once that printed move onto something lager. I printed this http://www.thingiverse.com/thing:180851, just with a brim and no supports. Came out very well and just popped off the build plate when it cooled.

 

Thanks for the kind words Mike, and thanks for the added tips guys.

Another word of advice. When you run into a problem with a print, make ONE change at a time on the same part to try and figure out the issue. Trust me, it will save hours and hours and hours of frustration later if you understand what fixes a particular problem. And if you think everything was right, and don't think it should have messed up...try again with same settings, I have had it work the second time around.

I have found an outstanding method of sticking the parts, using adhesive vinyl sheet and then scuffing it with 1,000 grit sandpaper. It works great unscuffed as well. The finish is still very good on the bottom with 1,000 grit paper as well.

The main factors I have personally found for problems once I was dialed in are:

Temperature-extruder <----try this first. I would bump it up 5-10C and test
Temperature-bed <----helps on first layer, can help combat warping
Speed < ---try lowering 10mm/s and test

Once your machine is set up and getting good prints, different files are going to print differently. I have had best luck printing as hot as I can without curling. You get great adhesion, the filament flows easily and usually comes out great. Sometimes too much heat will curl a part, so you may have to dial it back or position part differently. Overhangs will curl easily.

If you have a heated bed, it really helps the first layer of PLA. The filament doesn't get quite the shock of hitting a cold bed and it gives it a chance to bond hard. If you don't have a heated bed and think it may help, you could always warm it up with a hairdryer or heat gun.

As far as speed goes, I have had way more luck slowing it down but stay around 30-40mm/s.

One other thing to always check also.....The two screws with springs on the extruder. Those must be tight! Finger tight till they stop, I have had prints fail from them not being tight enough. Very difficult to diagnose as well...so just keep em tight to eliminate that variable.

 

I have a question fitting for this thread that I have been struggling with and I'm sure I am not the only one.
How to prevent tall and small areas from looking like melty blobs?
With something simple and mostly flat yet has a tall narrow part to it like say one of these wall hooks, http://www.thingiverse.com/thing:225672, I get a perfect, sharp print until it gets to the thin hook area and it just spirals me a melted blob so to speak. I'm sure a few of you know what I mean.
The nut and bolt print an example as well. However mostly I'm wondering how to deal with a part that is printing great until you come to a tall tight spot that just can't handle it.

My first thought is wait for it to come to that area, lower the temp and speed it up but I dont see any difference when I try...

 

Are you printing with support? It shouldn't have to on that, but sometimes the slicers have a really bad way of slicing certain objects. If it starts in the wrong area it may be trying to print in mid air.

Not sure if I am picturing it exactly right, but I would assume print would be fine but bottom of that overhang would come out stringy?

 

No supports, and yeah i'm used to a little sag in overhangs sometimes, this is different though.
Think something like the top few steps of the calibration cube steps, http://www.thingiverse.com/thing:24238. With me the top step comes out too melted. More of a round blob really. I guess I pictured this as being more common.. small areas getting too hot to print. Not cooling too close to the hot end.
Its printing normal, not skipping layers or trying to print in the air first. Just too damn hot from the base up lol.
I'm on pla and i've tried from 208 degrees down to 180 in testing and keep getting the same effect. tried with speed from 100-170. Layer height at .2046

Keep in mind everything else prints great in the part, right until its too small of an area that the heat keeps it from cooling. I've put a fan on it and it helps a little, but still warped and deformed.

 

AxisLab,
The problem with those small protruding areas is that it is extruding over a previous layer that has not cooled enough. Larger areas take more time to complete which lets the lower layer cool. If you use Slic3r spend some time adjusting the Filament Settings Cooling selections. These setting allow you to proportionally increase the fan speed and slow down the print speed depending on the estimated layer time. I found it is necessary for the structures you mention in PLA and sometimes for ABS. The problem for ABS is that if the fan speed is too high it can cool the lower layers enough to start popping the print off the bed. With hairspray I can hear a disturbing cracking sound when the fan goes on.

 

Which settings do you suggest Steve to slow down that specific area? the bulk of the print is solid, it just comes down to those tiny sections that the hotend has to focus on for longer than a couple passes.
Here's a small example from the test space invader hook I linked earlier, the majority of the print was fine, I waited until just before the start of the hook part and dropped my temp down to 180 this time, my lowest yet in trying, and instead of speeding up this time I dropped the feedrate down to 35mm/sec. Still getting the same effect and this was moving slooow, The layers of the hook part alone was 7 minutes. Before I had it cranked up anywhere from 100-170 trying to keep the hotend moving up quick and it was just as bad.

It's in silver so it looks even shinier but melted none the less.. Looks less like a wall hook and more like a space invader that's "happy" to see ya'. Not quite what I'm goin' for..

 

The Cooling settings are for exactly the mashed nose problem. You can take a guess at the layer print time for the nose and adjust the "slow down if layer print time is below" setting to make sure it catches it. Then adjust the "Min print speed" setting to slow way down only for that section and give it time to cool. If adjusted correctly the rest of your print will run at a normal speed and the small area sections will slow down and the fan will go to maximum. You can keep these setting for all prints because it will only be enabled if the thresholds are reached and they are needed. Below is an example for some PLA filament. This should help a lot. You can even change the min print speed down to 1 mm/s but it will take a while.

 

Thank you for the guidelines, my settings were the same except for the "min print speed" I was the default 10. I tried it at 3 then 1. Holy cow you were right, I have never seen my robo move so slow.
Sadly it wasn't the problem, ended up worse and I will have to experiment.
I took a picture of my failed tests but then took a second picture to keep things on the positive side for new people like me.

A failure is always a learned experience. If you find a way to turn that failure around you may end up with something better than you were looking for.

I wanted a simple plastic bag hook next to the dryer to put the lint in, what I ended up with trying over and over is my own alien army to cheer me on!


The pile of failures lol


Turn em around to plan an invasion... Not quite I guess, but It's better than throwing them away ..

 

Just to make sure - did you verify the that fan is blowing and at full speed? With a working fan, really slow printing for narrow areas and your extruder temp experiments the only thing I can think of is that you have some strange filament.

 

I'll play with it some more in the morning, as for a fan I'm using a powerful desk fan I have, thing blows pretty strong. I don't have a fan built in. Must be just what it is I guess. The fan I'm using blows plenty more air through there than a small one would I would think, I dont sit in front of it long watching because I get too cold myself.
Filament is good it seems, I print plenty of other good things as long as they're slightly larger, plus it does the same with both colors I have. Both Robo filament. Green and silver.

One thing I may need to find a way around it it seems like really small areas like this it prints solid, so going around and then filling in is just too much heat to cool. Is there a setting I'm not seeing to prevent that or force the small areas to print hollow?

It's a small piece so maybe if you have an extra 10-15 minutes sometime in the near future could you maybe try it out yourself to see if it is a problem in the file itself? It's #6 small on here http://www.thingiverse.com/thing:225672
Although I'm 99.9% sure the issue is on my end of course. More curious I guess.

 

AxisLab,
Sorry for the huge delay in printing this. I finally got my printer back together after installing a new bed and making other modifications. The old one that was cracked in shipping but I used it anyways for a while. It finally cracked further making it unusable. Back in November when I got the printer and cracked bed Robo3D sent me a new bed immediately.

The space invader printed out pretty well in my opinion. This was printed at 0.333 mm/layer and with the minimum print speed of 1mm/s in the cooling section. The nose is actually quite sturdy and I think looks better than the photos show. This was cheep amazon PLA that is really glossy. I'm really not sure what is happening with your prints unless you filament has strange properties or there is something wrong with your extruder thermister.

The Slic3R settings are below in the slic3r.ini file ( had to rename it .txt to upload it for some reason).

 

Okay thank you so much, That is actually much closer to what my later tries were looking like as well, In the dog pile of failures picture I posted above, The alien in the absolute front (just touching the white line with his 'hand') was the last try with your tips, It is sooo close to being there. definitely need to work on the cooling but your settings got me much closer.
The pictures of the makes on thingiverse are completely squared and that was what I was going for. But seeing the hook edge's on yours are still rounded like mine, helps reassure me that may be a lot harder to get it that fine.
I really thank you for taking the time to try it out and show me, seeing it from another machine gave me a lot of insight and the tip about slowing down the cooling time will prove to be extremely helpful.

Thank you again so much.

 

Noob question: Whats the best way to clean your print bed of old PLA? Acetone? Rubbing alcohol?