Print issues at a certain height

[htbui 0]

I have Ultimaker 2 Plus Extended for about 2 weeks. Last night, I try to print the wind turbine that is provided in Youimagine website. Here are some pictures from the prints (I printed the top blade - Group A) . I used the settings that are recommended in this link "https://ultimaker.com/en/tips-tricks/19639-vertical-axis-wind-turbine"

I also did not change any settings from the machine, for example, the acceleration is still 3000 mm/s^2, and the jerk also the same as 20 mm/s

After the first print, I changed the orientation of the print and move it a little to the back of the bed, close to the z rod. The result was a little bit better, but I noticed that at a certain height, the quality was getting worse

There are also some imperfections in the blade, I guess that have to do with the retraction problem and I am not worry too much about it

Beside the inside of the blase was bad, the outside looks perfect for both of my prints, I guess that is what the designer intended.

Is there anybody has the same problems with me?

Any suggest on how to fix it?

Thanks

Hieu Bui

[gr5 2,167]

Don't make me read the thingiverse settings. What was your print speed, layer height, and temperature? I recommend 35mmsec, .2mm and 230C to start. If you are patient then 35mm/sec, .1mm and 210C. This should minimize underextrusion which is what your problem looks like.

HOWEVER

It could indeed be the Z. Many people have trouble with their Z such that it drops down too far suddenly. Usually it sticks for a layer or 2 and then drops 2 or 3 layers all at once. Usually it's the ball bearings. To test them, unscrew the Z ball bearings from the plate and slide them up and down by hand and check the feel. You don't want or need any oil on the Z rods. Clean any oil or dust off. If the Z bearings stick at all you need to remove them and clean them with WD40 and dry them well.

Alternatively put something heavy (about 1kg or 2 pounds) on the back of your Z stage. This also often helps.

[htbui 0]

I am sorry, I printed it with

 

• Layer height: 0.15
  
• Temperature 210 - bed : 60
  
• Shell thickness 0.8
  
• Bottom/top thickness 0.6
  
• Fill density 0%
  
• Print speed 40
  
• Nozzle size 0.4
  
• Travel Speed 200
  
• Bottom layer speed 15
  
• Minimum layer time 10
  

 

I think my z rod still OK because I stopped print the win turbine and printed something else, the other print look ok

I will try to print it with 0.2 layer height to see if there is a different

[Job_van_gennip 23]

I had the same problem when printing them. It was a real pain in the ass and the imperfection ruined about 3 of them for me. The problem is that with such a thin high part the vibrations become too strong and start to cause problems.

For me putting the printer on a more solid basis helped a bit and allining the print so it is in line with the motion instead of perpendicular to it. You could also try taking up your thicknesses to 1 and fill to 20 to make it a bit more sturdy and drop the travel speed and acceleration speed a little to make sure it vibrate less.

[gr5 2,167]

If it's truly vibrating you could add some angled support columns that join with the part 1/4 and 1/2 way up the side. Make them at least 10mm across - actually I like the 20% rule: Supports width/height should be > 0.2. If you are good with cad you can even taper the supports to make them at half thickness near the top of the support.

[htbui 0]

Thank you for the suggestion. I also noticed the vibrations. I printed some feet for the printer using Ninjaflex that I printed using my friend printer. I don't know if that help improve the quality or make it worse

The print just finished, the layer height was increase to 0.2, and rotate the blade to the back of the bed. The results is better

I will try to print with the suggestions that gr5 provided

Edited March 1, 2016 by Guest

[X_chinese 0]

I've tried it on my model with the recommended settings and with slower printspeed. Everytime I get this:

The nozzle is pushing the thin side everytime.

It's very frustrating!

[htbui 0]

Hi X-chinese, I printed mine with 3 parameters to make it a little bit stronger. It helps reduce the vibration quite a bit.

[gr5 2,167]

"with 3 parameters"?

Oh - 3 brim perimeters? x-chinese make sure the bottom layer is well squished into the glass - you might have to rotate the 3 leveling screws 1/4 turn each the same amount to get the glass closer to the nozzle (counter clockwise).

And htbui had .8mm shell so make sure you have at least that.

Make sure your fans are at 100% (in the tune menu while printing) and feel the airflow.

Try printing 10C or 20C cooler - maybe around 190C. And also print slower so it won't underextrude (PLA is more like toothpaste at 190C).

This is a tricky part to print. I'm not surprised the nozzle hits the thin part. That's somewhat expected but some printers are slightly better than others. The cure for that is more fan. Lower printing temps help also. Tons of information about this "raised edges on overhangs" issue where the print head hits the part here:

http://umforum.ultimaker.com/index.php?/topic/4094-raised-edges/