PLA prints get loose... what's the problem?

[DdeWaard]

hello.

i finished my Rostock MAX 2 days ago and i have had some nice prints and some bad ones
on almost all my prints the layering(0.2 mm) is extremely accurate, builds straight up and it looks very beautiful
the first and last layers (expecially the last layers) turn out quite ugly, when top is in rectangular, the lines are around 1mm wide and don't hit the edges so there are some gaps. has anyone any tips?

I tried the famous rook a few minutes ago and it worked fine for about 65/285 layers then it got loose.
the vertical layering quality was beautiful but after the said 65 layers the rook got loose off of the borosilicate build plate coated with painters tape.
glass plate at 40°C for first layer and 20°C for later layers. extruder at 190°C
so the main question is:how did this happen?
-was the painters tape too smooth? I used light yellow 38 mm wide easy to remove tape. it sticked well to the glass plate. do i need to buy the blue version?
-do i need a raft or brim to make the surface area bigger?
-does the heated bed have effect on the PLA? i have a regular 30cm room fan blowing on it because i don't have small fan mounts yet

the rook was about 30 mm in diameter and so far about 15 mm height before it got loose.

thanks in advance,

Demy de Waard

[Eaglezsoar]

hello.

i finished my Rostock MAX 2 days ago and i have had some nice prints and some bad ones
on almost all my prints the layering(0.2 mm) is extremely accurate, builds straight up and it looks very beautiful
the first and last layers (expecially the last layers) turn out quite ugly, when top is in rectangular, the lines are around 1mm wide and don't hit the edges so there are some gaps. has anyone any tips?

I tried the famous rook a few minutes ago and it worked fine for about 65/285 layers then it got loose.
the vertical layering quality was beautiful but after the said 65 layers the rook got loose off of the borosilicate build plate coated with painters tape.
glass plate at 40°C for first layer and 20°C for later layers. extruder at 190°C
so the main question is:how did this happen?
-was the painters tape too smooth? I used light yellow 38 mm wide easy to remove tape. it sticked well to the glass plate. do i need to buy the blue version?
-do i need a raft or brim to make the surface area bigger?
-does the heated bed have effect on the PLA? i have a regular 30cm room fan blowing on it because i don't have small fan mounts yet

the rook was about 30 mm in diameter and so far about 15 mm height before it got loose.

thanks in advance,

Demy de Waard

You are supposed to use the blue painters tape.
Read this thread, you may not need to use any tape. http://forum.seemecnc.com/viewtopic.php?f=36&t=4141