Ultimaker UPET (CPE) Issues

[mfknjohn 6]

Okay so Im trying to make a nozzle part for work and PLA isnt quite strong enough so Im using UPET or CPE as its known now, Its the Ultimaker brand that came with my ultimaker 2 ext. I havent really been having problems but lately the parts start out great and when I come back into the office I see that one side has warped ridiculously and now is completely off the buildplate? Any suggestions as to why this keeps happening?

You can see in the picture about halfway through where the material started warping..

Edited June 18, 2015 by Guest

[jens 9]

I had some warping issues with larger pieces printed in PETG (not sure if this is similar, but I guess so). There, it helped a lot to slow down the cooling to around 50 % max (height depending on part height/size) and lower the bed temperature as much as possible (somewhere around 60 °C; a bit of trial'n'error required as PET doesn't stock to the glass as well as PLA). Reducing nozzle temperature might help as well, but will also reduce interlayer bonding ...

Last thing, as a general solution to many many problems (except for having no time): if you could, try lower print speeds

EDIT

For some tricky parts, I print a thick first layer with 20 to 60 brim lines (brim? skirt? I mean the ones that are fused to the actual part) ...

EDIT 2

Clean the glass bed thoroughly

Edited July 3, 2015 by Guest

[gr5 2,268]

Did you include brim? That's critical.

I have never printed PET (I have an unopened spool - I will get to it eventually!). But for ABS and PLA it helps to be above the glass transition temperature because then instead of having the extreme pulling forces lift the part off the bed, instead it gives way ever so slightly. wikipedia says glass temp is 67 to 81C so I'd try 85C bed temp. The 50% fan is a fantastic idea also if only to help layer bonding.

Did you use glue stick? Be careful because I've heard that a thin layer of gluestick holds down PET so strongly that it will pull up tiny slivers of glass into the print when you remove it. So I recommend you let the part cool completely to room temperature and don't force it very strongly - if it's hard to remove put it in the freezer for 20 minutes first.

[gr5 2,268]

Oh and keeping the air warm inside the UM2 help with plastics with higher glass temps because they have more shrinkage. So put some plastic on the front of your UM2 and put a printer box (box that holds a ream of paper) on top of the printer such that there is a big air hole where the feeder tube goes into the box. This will warm the air to around 40c to 50C and you will get less shrinkage as you print.

[mfknjohn 6]

Did you include brim?  That's critical.

I have never printed PET (I have an unopened spool - I will get to it eventually!).  But for ABS and PLA it helps to be above the glass transition temperature because then instead of having the extreme pulling forces lift the part off the bed, instead it gives way ever so slightly.  wikipedia says glass temp is 67 to 81C so I'd try 85C bed temp.  The 50% fan is a fantastic idea also if only to help layer bonding.

Did you use glue stick?  Be careful because I've heard that a thin layer of gluestick holds down PET so strongly that it will pull up tiny slivers of glass into the print when you remove it.  So I recommend you let the part cool completely to room temperature and don't force it very strongly - if it's hard to remove put it in the freezer for 20 minutes first.

 

HAHA yea.. found out about the gluestick taking up pieces of glass the hard way, but thank god i work in a glass production company haha. I found out using the brim, and adding a little heat to the buildplate helps, not all models warp as bad as others but thats just something that comes with 3D printing, NOTHING is the same. I have it all worked out now but thank you for replying!