print bends on sides

Hi,
I got a problem when printing wide objects. as you see in the attached photo it bends only on the sides and only for wide prints.
I think it might be due to the fans that cool the wide sides more than the center. any suggestions?
I am printing PLA on glass heated to 60C.
Thanks


Edited 2 time(s). Last edit at 10/10/2014 04:07PM by EEstudent.

Have you tried printing on hairspray, glue or blue painters tape?

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Yea, you really need more than just glass. I prefer the purple glue stick but I dissolve it in water so I can easily paint it on. Pops right off after fully cooling.

- don't heat the bed for PLA !!
- i used to cover the bed with kapton tape and it was a simple and effective sollution for small objects, just had to clean the tape with aceton every few prints
- but kapton was not enough to prevent warping of the biggest objects, so I am using Pritt Universal glue which is applied to the glass and smeared with an old credit card



- I also have a strong 80mm fan blowing across the bed, which I think is crucial to prevent warping

So for PLA don't heat the bed, apply glue and adequate cooling. Read more about PLA and warping in this thread

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All about delta 3d printers in one place [www.deltarap.org]

I am confused. some told me to use higher temps for bed and some told me to turn it off.

I use 70 degrees for pla, it is important for the first few layers to stick right, after that you can lower it to 50 or turned off. Don't waste your money with blue tape or kapton just apply a coat of purple stick glue. Most of the problems with lifting are more related to first layer hight than any other thing. I used S3D and if i set a first layer to 75 to 80% I could print small parts without glue.

You won't get an exact answer for your setup, it depends on speed, temperature, filament, bed material, cooling.......
I use "trial and error" approach to find out what is working for me and that never fails.

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Quote
DinoK
- don't heat the bed for PLA !!
- i used to cover the bed with kapton tape and it was a simple and effective sollution for small objects, just had to clean the tape with aceton every few prints
- but kapton was not enough to prevent warping of the biggest objects, so I am using Pritt Universal glue which is applied to the glass and smeared with an old credit card

1338367975380.png

- I also have a strong 80mm fan blowing across the bed, which I think is crucial to prevent warping

So for PLA don't heat the bed, apply glue and adequate cooling. Read more about PLA and warping in this thread

I just made a new discovery. With this method the objects stick to good and I have a hard time getting the object off of the glass.
So I was watching the video on Youtube about using pc-duster can spray to cool the object so it almost pops off by itself. I took the cooling gel bag from the freezer, put it on the object for 20 second and removed the object from the bed with minimum force. It probably works with frozen vegetable too

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