Unwanted seam appearing in prints on FFCP

[Geoff]

Update:
I found the culprit.. it's the acceleration
Left one is without acceleration and right one with acceleration.

https://drive.google.com/file/d/0B0w...ew?usp=sharing

It's a firmware problem and I can't print without acceleration because my prints will last x5

How can I fix this?

Manually with Simplify3D doesn't work? So you press Edit current process, and click the "Other" tab and have tried changing speed down there too?

if that doesn't work you can also try slic3r (not hard, just have to input the bed dimensions really. Slicer profiles do nothing other than change variables, so technically the gcode is the same for all machines that it pumps out, which is a pretty generic gcode, but the prints seem ok, it has pillar supplrt also like S3D.

[Horia]

The bulge almost disappeared after changing some JKN values and acceleration.

[djprinter]

Have you tried setting simplify to use random start points? I always get a visible seam if I don't check that box.

[Horia]

After a lot of tests and calibration we found out that there is inconsistent movement to the X and Y rods.
This could be because of bearings or belts. Don't know yet.

Edit: Saw on a lot of forums that the movement should be "smooth" for the carriage but we can't measure that. Probably we have to disassemble each component to find out what makes the hiccups.

If anyone encountered the problem and resolved it please help.

[Horia]

More troubleshooting:
slowfast.jpg
click to enlarge

[Geoff]

Man, I have to be honest I think you are chasing dragons to an extent.. I have printers that cost me three times more than a flashforge and they leave a reasonable seam - and random seams are pretty ugly - but that being said if you can get rid of it, please tell us how.

I know this is an odd question, but all the shots so far have been of that same blue fliament, have you tried just for the hell of it, another type of filament? I know from experience the clear PLA and ABS can get rather goopy.

[Horia]

Yes, we used the same filament. I was talking about the bulge that appears after sharp corners. The Z seam is where we put it (on another face of the bag handle).
The story of our FFCP is a little complicated. We received the printer in october. We tested some models but after a few prints we realized something was wrong and sent it back. Before we sent it there was no bulge after sharp corners.
We got it back from the reseller with the problem fixed but now those bulges after sharp edges appeared.

This is the reason we are still dealing with this problem. Furthermore a few people printed the same models we did on their FFCP and they were spotless.
We will eventually change the Creator Series Filament (it's running out) and test other brands of PLA and ABS.

[curious aardvark]

I have no clue what's supposed to be wrong with that print.

What slicer software are you using ?

[Horia]

Simplify 3D
The problem is that when I up the speed (as seen above the red line) there is a bulge appearing right after the sharp corner. That happens to all the prints.

[jfkansas]

Crank up your JKN values. Higher speeds need higher values in those due to the greater speed changes.