pimples on surface

In the past few weeks I have been getting more and more pimples on the sides of my print.

Originally it was printing flawlessly without artifacts showing up. When I print I am seeing that the nozzel is freezing for a few miliseconds like its waiting for the next command. I am printing from SD card but did not have this issue a few weeks ago.

I also noticed that on flat parts this does not happen only on curves.

Picture [imgur.com]

I have tried changing SD cards, turning down the heat and slowing down the print but it has not made any difference.

Using Slic3r 1.0.1, disabled random starting point, using bowden extruder so my retract is set to 3mm at 50mm/s, like I said my settings have not changed these pimples have just randomly started showing up and now they are getting worse.

Edited 3 time(s). Last edit at 06/04/2014 07:55PM by vcazan.

Have you tried using a different slicer like cura to see if it's a code issue? I had similar problems with slic3r but don't know why. Cura seems to make cleaner code than slic3r but has other problems that make it difficult to set up but it's good for a comparison to see if that's the problem. Good luck.

This sounds very similar to my issue...

[forums.reprap.org]

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Harleym
This sounds very similar to my issue...

[forums.reprap.org]

Wow I think you are like 99% correct. I have a delta printer and I have a graphics LCD screen. I recently updated to the marlin FSR firmware that was posted and I suspect that it might have somthing to do with that. I will try taking out the LCD screen from the code and seeing it that helps.

The weird thing is though that I have the exact print that I noticed it starting and the first half of the print was flawless but then the next half started having all these pimples.

Could it be that the Arduino is getting slower with age as I have been running it almost 10 hours a day for 4 months or so?

Got it working by removing the LCD code from the screen. But still unsure why it slowed down after 3+ months of working with the same configs.

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vcazan
I recently updated to the marlin FSR firmware that was posted and I suspect that it might have somthing to do with that.

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vcazan
Got it working by removing the LCD code from the screen. But still unsure why it slowed down after 3+ months of working with the same configs.

Probably because it is so close to the limits that simply adding a subroutine to monitor the (analog?) FSR input was enough to push it over the top.

The Deltabot Google group has a thread about using the Adafruit Trinket as an FSR controller, which can then send a digital signal to the Z-min endstop pins of your controller board.....

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vreihen
The Deltabot Google group has a thread about using the Adafruit Trinket as an FSR controller, which can then send a digital signal to the Z-min endstop pins of your controller board.....

That is a good idea, might give that a try.