Prints Curling Up at the Corners

Summary:

Printed items are curling up at the corners and then losing grip from the platform

Prints Curling Up at the Corners

SBC 07 Jul 2012 11:25

When I print, I am often finding that the corners, or sometimes one whole edge, are curling upwards and lifting off the platform. What then sometimes happens is that the object comes loose from th eplatform and I lose the whole print. At the very least, one edge or corner is thinner that the middle.

Now I think that it is better when I increase the temperature of the build platform. Is anyone able to confirm that I am on the right track? What temperature should I be running the platform at?

For information, I am running a Thing-O-Matic with a Mk 7 stepstruder and an Automated Build Platform. Softeware being used is ReplicatorG 0037 with Skeinforge 35 and Python 2.7. Firmware is V3.1

Re: Prints Curling Up at the Corners

Jetguy 07 Jul 2012 11:45

Heating the bed is only part of the problem.

On the quest for ever better finish quality, most dial down the amount of plastic and layer hieght squish. While this makes greating looking test cubes, you have poor bonds between layers. More plastic is the answer and the easy fix is to change the pinch wheel diamter in print-o-matic to a lower number than the stock 10.98. I use as low as 6.98. Regenerate gcode using the new setting.

Re: Prints Curling Up at the Corners

conceivecreate 07 Jul 2012 14:09

I have the same configuration as yours .. except I use ReplicatorG 34. I use ABS filament (1.75 mm) with extrude temp of 220C and heated bed temp of 110C. Skeinforge 35 generator creates the "start" file where these temperatures are different (I remember that the bed temparture was 100C). I have been quite successful at bed temperatures of 120C but then there is a lingering smell of plastic in the work area. I am using painter's tape. I do not have curling issues with small builds like 20 mm calibration cube but I sometimes see it on scaled up versions of the 3D-Knot. I will urge you to read through
wiki(dot)makerbot(dot)com/configuring-skeinforge

and

www(dot)makerbot(dot)com/docs/software/skeinforge/

these have helped me make much better prints.

Re: Prints Curling Up at the Corners

SBC 08 Jul 2012 04:02

Thanks for the replies. I should have added that I too am using 1.75 mm ABS. I should also have added that I am new to all of this so please forgive the many dumb questions that I am sure to ask.

Conceivecreate, I will go read the documents referred to above, but can I please ask you to explain more about "I am using painter's tape"? Am I correct to understand that you have covered the conveyor belt with painter's tape? As in the entire belt? I have seen heated platforms covered in kapton tape, but then that is not a moving belt.

If that is what you are doing, then any tips and pointers for applying the tape would be appreciated. Thanks

Re: Prints Curling Up at the Corners

conceivecreate 08 Jul 2012 10:36

Originally, I had Automatic Build Platform (ABP) with the conveyor tape. It was a great idea but the conveyor belt wrinkled in just a few builds. So I have removed the conveyor belt - the aluminum tape surface is covered with masking tape (I called this "painter's tape" - this is the blue or white tape normally used when painting drywall to protect wood surface - you can get this at any hardware store). People have used Kapton tape similarly. In either case, the conveyor belt is removed.

Re: Prints Curling Up at the Corners

Jacob Bruner 08 Jul 2012 16:00

Hi, I had the exact same problem.. your using the ABP i see, the belt thta runs along it is never completely flat causing a warped building platform. Makerbot sells a aluminium plate to put on the heater board. If you remove the belt and put the aluminium plate on it with some kapton tape and your builds will be perfect

Bibliography

: labfull source reference

Re: Prints Curling Up at the Corners

SBC 09 Jul 2012 04:46

Thanks Jacob. That's pretty well where I reckon I'm heading.

In the mean time, I have noticed something. When I get an edge curl upwards, it is always on the left and right of the platform, not the front or back. This is true even when I rotate the object on the build platform - I've been doing some things that are rectangular. So it looks as though heat is being lost out the sides of the conveyor belt. I could probably come up with a few ways of reducing that heat loss, but I do not see that the conveyor adds sufficiently to the printer functionality to persevere down that path.

By the way, if the conveyor belt is removed, do you continue with the machine type (driver) defined as "with ABP" or "with HBP"?

Re: Prints Curling Up at the Corners

Jetguy 09 Jul 2012 11:30

So it looks as though heat is being lost out the sides of the conveyor belt.

Yes, that's what we've been saying because the sides lift, and when they lift, they have less conduction so more heat is lost, equalling more curl and so on. It's a feedback reaction that cannot be stopped. Hence, why we say the ABP is nothing but a toy, it's not for real printing.

By the way, if the conveyor belt is removed, do you continue with the machine type (driver) defined as "with ABP" or "with HBP"?

Doesn't matter. Both heat the bed, the wipe routine of the ABP might be better (because it lines up with the wiper tab), and at the end, the motor runs but nothing happens.

Last edited on 09 Jul 2012 11:30 by Jetguy Show more