Design-print fail

I’ve been slowly working on the design of a printable (and fully MakerBottable) sonic screwdriver.  This model of the sonic screwdriver is built up of a number of concentric cylinders, has several significant overhangs well in excess of 45 degrees, and is larger than the MakerBot’s built capacity.  In order to deal with these design problems, I modeled it in sections.

In order to make the overall result something I could just pop/snap/slide together I designed it making some sections which were split vertically and other sections which slide around those sections to keep them together.  In order to make the parts quickly printable I designed all the parts at around 0.5mm thickness.

About 40% of the way through the print one of the vertical sections wasn’t coming out properly – probably because it was too thin.  The parts were too thin and flexible and ended up tearing between layers and just being too flimsy.

I also noticed something odd – the extrusion was too thin on that side of the model.   I can’t be sure why this is happening – but I suspect it’s due to the extruder not getting a good enough grip.  Perhaps I need to floss the extruder pulley or install a new extruder idler wheel.  However, it doesn’t explain why the extrusion was too thin on just that one side and no other spots.

Suggestions?

5 Responses to “Design-print fail”

  1. […] my design-print failure I thought it was about time I recalibrated my […]

  2. Dna says:

    Hydraraptor had this problem …

    http://hydraraptor.blogspot.com/2010/07/bit-of-drag.html

    might be similar ?!?

    Dna

  3. MakerBlock says:

    Hmm… that problem appears to be related to poor infill on one side due to too much drag/friction and not enough pull on one side of the build area. I am thinking this isn’t the issue because unlike a Mendel the print head/extruder is relatively stationary. With a Mendel the increased resistance to the extruder pull on just one side is probably caused by the print head moving in that direction causing a lateral pull on the filament. In the case of my MakerBot – there shouldn’t be such a problem. In any case, I’m using a very inefficient and error prone method to prevent this problem – I spool out a bunch of filament and check on it every 10-15 minutes or so.

  4. Dna says:

    Even on the Makerbot, I’ve noticed that it can strain to pull the filament through if it is getting caught up. Less so since I changed to the new drive gear.

    Anyway it was a thought …

    Dna

  5. MakerBlock says:

    @Dna: Dude, I totally appreciate the insight. I just ordered (ordered/will be getting for my birthday) a the new extruder gear from MakerBot. Hopefully this will help!