UM2 Very bad first layer ABS

[joop 0]

We have just received the UM2 and after we have printed the UM robot we started with an iphone case. I have leveled the heading glass bed several times but still have a lot of problems printing the first layer. See image:

I don’t think it has something to do with leveling the bed because it is not only one bad corner and i have redone leveling 3 times without any better results.

 

• Material: ABS
  
• Layer heigt: 0.06
  
• Print speed: 50mm/s
  
• Temperature standard setting: 260c
  
• Building plate temp: 80c
  
• Used glue stick
  

 

Not only are some layers almost transparent that thin but there are also a lot of bumps. The surface is not flat. While printing the glas bed was pushed down because of the bumps. What am i doing wrong?

Also, is there a guide for using the right settings when using ABS with a heated bed? There are a lot of settings but for a newbie it is very difficult to find out where to start and how and why a setting should be applied.

 

[illuminarti 18]

Did you set a different first layer height? Trying to print a first layer that is just 0.06mm is going to be very tricky to get right. You would do better to print the first layer at about 0.2mm or more, so that any slight variations in the level and flatness of the bed won't be so critical, and you won't be dragging the nozzle through glue.

 

[cyclone 0]

I've been printing with 3d Printers for a few years now and .06mm is a very low layer height. I print around there to show off a gorgeous model like the Yoda. It's kind of a waste of printer time to print that thin for a phone case.

The first layer at the height is very tricky. As illuminarti says set the first layer height to .2 or at least .15.

 

[gr5 2,173]

You need to level to within about 25% of the first layer height. In cura you can set the first layer height thicker but if the first layer is .06mm you need the bed accurate to about .02mm. This is one fifth the width of a piece of paper. Also when the print head warms up it expands so you have to level with a hot print head, then after you get it perfect with paper, you have to twist the 3 knobs a little more to get it a little closer. How much to twist? I don't know yet. I guess one can figure it out with 2 pieces of paper to see how much to rotate those thumb screws to achieve one width of paper in height change.

Your photo looks EXACTLY like what I would expect. In some places you are too close to the bed and the pressure builds and builds until suddenly it can't take it and you get lots of extra filament squirting out the side of the nozzle which causes blobs, or thicker areas.

What I do with the UM Original is print an extra large skirt and twist the Z axis by hand (difficult to do on the UM2) fighting the stepper. This does not dammage the stepper motor. By the time it does the final skirt pass either I have levelling perfect or it's time to abort and start over.

 

[mattkaz 0]

I could not get the paper leveling perfect on my um2 so I found a calibration file on thingiverse (no link, im at work) it prints 3 squares over the leveling screws and I then adjust whilst printing that way the bed and nozzle are at temp.

[gr5 2,173]

Whatever works!

 

[joop 0]

I have had a lot of problems with the UM2 and finally i have received a new one. I am now printing with PLA and is is much easier. no glue and a heated bed at 60c. Thanks everybody for the help.