First-time Printing Glitches

[mark 0]

Hi All,

I just assembled my Ultimaker yesterday, and started printing today, and while the prints are getting better I need quite a bit of help. For some background I am using Cura 12.08 to print PLA at 230 degrees, a print speed of 30 mm/s (keeping it slow while I figure things out), and a layer height of 0.2 mm. So here's my problems/questions:

1) There is a leak between the aluminum plate and the nozzle, which occasionally drips onto the object being built. Is there any fix besides trying to put on more plumber's tape? I'm not really sure how to do that as it needs to be heated so the plastic doesn't become a problem. On a related note, my kit came with an ABS fix kit -> Should that be run through despite me using PLA? And what is it supposed to do exactly? (Also, what's the best way to feed it in?)

2) When printing bigger things the first few layers sometimes curl upward and get unstuck. From reading the forums and other blogs I thought that was only an ABS problem. Any suggestions to make the first few layers stick better would be appreciated.

That's really it for now. I'm loving the quality potential I've seen so far and can't wait to get to more consistently successful prints .

-Mark

[spooner777 0]

I dont know why it leaks but a bit more plumbing tape could help and also tightening everything.

To get it to stick better you have to try and get the print bed just a tiny tiny bit closer. You can alos try printing the first layer at 10-20% speed. That will give the material enough time to stick.

[jcosmo 5]

I'd lower the temperature, 230 is quite hot for PLA.

I saw a process for working out the "right" temperature for a particular piece of filament, posted by Joergon here : viewtopic.php?f=7&t=1253#p7731

I must admit I don't follow it religiously, I tend to just use 210

To stop leaks you can use the piece of ABS that came with your kit - run it through the printer at 260 degrees.

It will melt and fill all the gaps, and from then on when you are printing PLA you don't get hot enough to melt it, and thus don't leak.

To make your first layer stick better, lots of hints around. Mainly make sure your bed is level and the Z end stop is set correctly, so that you get a good adhesion to the blue tape. There are a couple of nice things that can aid with this:

http://www.thingiverse.com/thing:19912

Printing your first layer a little hotter, and a little thicker can help, don't enable cooling. When I was starting out I used to try using rafts, I've given them up as a bad idea, when you have the Z height set correctly you get good adhesion, and I've printed bolts over 6cm tall with nothing more than a 6mm "head" attached to the bed.

You can also, when using Cura, fiddle with the 'start gcode' to trick the printer into thinking the 0 Z position is actually 0.2 (or higher), and thus push the print closer to the bed.

Printing over a large area is always problematic, even with PLA, and you'll get curling in the corners as your print gets higher, but you should be able to get the first layer to stick well regardless.

Printing in a warm place can help with curling after the first layer - I don't know if anyone has tried enclosing their printer to aid in this?

The best mod for solving this is to add a heated bed (so I'm told - I don't have one, yet).

[mark 0]

Thanks for the advice. I first ran the ABS piece through and then tried printing again with a lowered first layer speed of 20 mm/s, heated at 210, and I manually set the z-bed to a good height before letting it print (paused it right at the start and then adjusted the bed). The results are great! Now if only I could get the print off of the build plate .

By the way I was printing out thing:11033, so now hopefully I can get this z-axis limit switch in a more workable position. Thanks again.

-Mark