First layer printed on the raft isn't sticking - ABS
 
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First layer printed on the raft isn't sticking - ABS  

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anthony.e2
(@anthony-e2)
Active Member
First layer printed on the raft isn't sticking - ABS

I am really new at this. So, now that I've gotten that out of the way, I am trying to use ABS to print some parts that will be used together. The part in this picture shouldn't have any curved edges. I've used the 30mm squares at the center, front, back, left, and right of the bed to calibrate the bed leveling about as good as I think I'm going to get it. I've read in other posts about the PINDA being heat sensitive, so between prints I move it to +100 to avoid heat soak from the bed heating up. I've also created a cheap 2' x 2' x 2' enclosure for the printer in an effort to keep a more stable printing temperature

So, I think I'm down to live-Z calibration. Also, I don't know if I'm using a raft correctly. I marked each of these with the live z adjustment I was using when I printed it.

Everything after .400 mostly or completely peeled off of the raft when removing from the bed. All of the bottoms looked like this, and the first couple layers didn't adhere properly as seen in these pictures. Also, the side walls of the print are curved and should be straight.

So, with all of that, it occured to me that I don'w know what the raft is supposed to look like. Below I have from top to bottom live z adjustments -.475, -.400, and -.425... yes I know they are out of order but I didn't notice when taking the pictures. Should it be a thin sheet like the top of this picture or should I be able to see the individual lines like the bottom two?

Should I be doing something completely different to get these parts to come out right? Are the rafts even worth it? Is there a better method for printing ABS? I think I've finally got the bed adhesion part down which took a few days, but I'm at a loss for this part. It's almost like it's skipping a layer and printing completely in the air on that first layer so it's not sticking. Any advice would be greatly appreciated

Posted : 04/09/2017 6:10 pm
AJS
 AJS
(@ajs)
Noble Member
Re: First layer printed on the raft isn't sticking - ABS

If the bottom is flat, why do you need the raft? Rafts are for models who's bottoms are not flat, so there is not a natural way to adhere them to the bed. In your case (I think) the bottoms are flat, and you should not use a raft.

Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…

Posted : 04/09/2017 7:43 pm
anthony.e2
(@anthony-e2)
Active Member
Topic starter answered:
Re: First layer printed on the raft isn't sticking - ABS

Thanks, I think you're right on that one. I did print one with a 2mm brim as a test after posting and it came out better. I have some other things that are more decorative I want to print. I was originally getting some issues with the first layer curling at the edges so I thought getting it a little off the bed might help.

Out of curiosity for my future prints, what is the raft supposed to look like? Should it be a thin film, or individual lines?

Posted : 04/09/2017 10:02 pm
AJS
 AJS
(@ajs)
Noble Member
Re: First layer printed on the raft isn't sticking - ABS

I would spend some time making sure your Live Z is set very accurately, see this post:

http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/-before-you-ask-troubleshooting-video-updated--t472.html#p39190

And the bed is very clean. To increase adhesion with ABS, you may want to add some glue stick (I don't do ABS so ...)

I have done very little with rafts, so I can't really describe how they should look.

Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…

Posted : 04/09/2017 10:31 pm
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