Printing with PLA: First Impressions

This weekend I ran out of ABS. Thankfully, a month or two ago I predicted that this would happen and bought a spool of 3mm PLA from reprapsource.com. If you do some reading, you'll see that PLA has a lot going for it:
  • It's biodegradable.
  • It has virtually no problems with warping.
  • The hot plastic smells like pancakes!

Could all those things be true?

Since my PLA came on a plastic spool, and that spool didn't fit in my MakerBot filament spindle, I had to improvise. I took the bottom half of my spindle out of the box and removed three of the vertical struts. That let me set the new spool on the Lazy Susan. Nice, right?


Well, revision one didn't work so well.

The fix was to add some sticks to extend the diameter of the base (at least until more of the filament has been used) and then to loop it through a guide above the spool so that it wouldn't catch on the sticks. Success!



I'm now continuing the process of upgrading my bot by building a Z-Rider to go along with my new lowrider. Here's the first plate of PLA parts I've made for the project.

First, I'll say that the switch was actually really easy. Here's my setup:

And here are my observations (in no particular order):

I actually didn't have to change any of my Skeinforge settings. However, I'm finding that I need to change my reversal settings as PLA is a bit stringier.

The printed parts are soft immediately after printing. I simply let them cool for a few minutes and then tap them with a wrench to separate them from the build platform.

I've had no problems with warping. For example, here's the mirror image of the part I just printed. Although the base is perfectly flat on both (my ABS prints stick like glue at 140° C on Kapton cleaned with acetone), the layers separated higher up on the ABS part. I believe this could be solved by covering up the sides of my MakerBot. However, now it looks like I won't have to.



I've read that there are two types of people who print with PLA: those who print on glass and those who haven't tried. Laura found some plate glass at the flea market a month ago, so I cut off a piece and started with it straight away. Like others, I'm very pleased with the results.

Another great thing about glass is that it's perfectly flat. My HBP has a slight curve in it that makes it difficult to print raftless. Now that I'm printing on glass, I level my platform in three spots and I'm done.

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