UM2+ printing problem

[fredz 2]

Any ideas what could cause this? Using PLA.

Edited July 14, 2016 by Guest

[neotko 1,361]

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#nostick Edited July 14, 2016 by Guest

[gr5 962]

Your nozzle is too far from the bed. Ignore the stupid leveling procedure. Just turn the 3 screws a half rotation CCW to move glass closer to nozzle. Turn them all equal amounts because presumably the bed is *level*, just not close enough.

[neotko 1,361]

Your nozzle is too far from the bed.  Ignore the stupid leveling procedure.  Just turn the 3 screws a half rotation CCW to move glass closer to nozzle.  Turn them all equal amounts because presumably the bed is *level*, just not close enough.

 

Why the leveling it's stupid? After toying with a um2 the other day I find it quite ok. But some info saying that it hopes for a 0.1 distance could help a bit. Anyway I also calibrate the 3 points and when printing I adjust the screws the same amount until I get a perfect first layer. Ofc after doing it right I rarely need to readjust it for a week or a month.

[ultiarjan 1,082]

I agree in with @neotko, I like the "official" bed leveling procedure, nothing wrong with it IMHO. Naturally it's ok to adjust the screws manually, but I always like to start with the level procedure. Obviously there are many ways to do it, i've seen people gently tab the underside of the bed iso using a piece of paper.... but I like using plain office paper, it's beter to feel friction with it compared to the glossy "callibration card".

I also use the paper method on my shapeoko...

[gr5 962]

Because the most common problem posted to this form is this one right here. This topic. And the cause is that people follow the leveling procedure perfectly. But it leaves the nozzle a the nominal distance from the glass. Which is a problem.

"nominal distance"? I mean that after leveling if you set Z=0.3mm then the nozzle is .3mm off the glass. Again - makes sense. But when you go to print you get exactly as shown above (well maybe in his case he was .4mm off the bed when trying to print .3mm).

Now maybe it's not the leveling procedure that sucks. Maybe it's Cura that should be over extruding the bottom layer a bit. But this is THE BIGGEST PROBLEM for new people using the printer. Parts don't stick because they are not squishing it enough. Only when they become experts (over 100 prints) should they be introduced to the idea of leveling it to nominal position for slightly increased dimensional accuracy on the bottom layer.

[BrayChristopher 35]

Screw dimensional accuracy on the first layer. It's over rated. Trim it off with a knife.

I agree that you need good "squish" on the first layer.

If it is important to me, I put a small champfer around the bottom of my part in the CAD software to compensate for the squish.

I set to nozzle about a post-it note from the glass and I print straight onto the glass (I do use some glue stick for XT).

I haven't had to level or adjust the bed in probably 6 months. I attribute that to the fact that I have stopped wrestling prints off the glass. I point a desk fan at the part and let everything cool down. The parts just "pop" off. You can hear little noises as the surface tension between the part and the glass breaks.

No more wrestling. No more paint scraper. No more bed leveling.

I haven't had to level or adjust the bed in probably 6 months.

Edited July 15, 2016 by Guest

[valcrow 144]

You can have dimensional accuracy AND a good squish by changing the "initial layer height" value to 0. (which will use your current layer height) Level it really well during the first layer and you will get a squish and a consistent layer height with the rest of your print without the weird elephants foot style expansion.