Tuning The Bot

Today I came back from a few days of vacation. Well I guess technically I’ve been on vacation since after finals, but this was a “going away” vacation. At first I was loath to spend about 3 days away from my newly completed Makerbot Cupcake CNC. It was sad; I remember realizing how much I would miss the smell of melting ABS plastic (which seems to give me a headache, need to work on that ventilation), and the noise of stepper motors whirring and humming and clicking away while creating some masterpiece of awesome. The few days away did me good however, and when I got back I was ready to start fresh and tune up the bot!

When I got home, the first thing I did was fire up the Makerbot, decide to print something (I forget what), opened the control panel in ReplicatorG, and rammed the extruder head directly into the build platform. Yes, I had become “un-used to” the fact that my Z axis is now going the right way, and I mistook down for up and up for down. That woke me up. After re-aligning the Z stage, I printed out a shot glass, and noticed that there were some problems including drooping, the raft not sticking, and a few other things. I assumed that it was either the new firmware, the settings I set in Skeinforge, or the new version of Skeinforge that came with ReplicatorG 0006. At any rate, it was a good excuse to fine-tune and learn more about Skeinforge.

The first issue was the raft. The raft would begin to stick, and then begin to peel up towards the end, getting caught on the tool head and messing up the whole build. After a bit of playing, I figured out that I was facing three problems. First, the raft temperature in Skeinforge was too low. I don’t yet have a thermometer capable of measuring the temperature of the extruder head (at least not one that I don’t plan to use for food), so I though I’d bump up the temperatures in small increments and see what worked. I also created das klein ErprobungMannchen so I could test my settings quickly and efficiently, and I switched to the acrylic build platform. Aside from being an awesome color, and lighting up when a flashlight is positioned above it, the acrylic build platform is far superior to the foam-board platforms. The ABS sticks to it, but it’s easy to get the raft off after the print, especially when the raft is still a little warm. It turns out that I needed the following settings:

My current Temperature settings in Skeinforge.

My current Temperature settings in Skeinforge.

Thus far I’m not convinced that this was the problem, or that I solved it properly. First, everything was working fine almost perfectly before I left, and now it’s different. I’m also not convinced that the latest firmware would cause a deterioration in the bot’s performance. The only explanation I could see for this problem is that perhaps the latest firmware and software were have been tuned in ways that brought to the surface imperfections in my setup that we “fudged” by the old software and firmware. The other possibility is that the temperature settings have changed, but I assume that the new Skeinforge is using my old settings.

I’ll continue to tune, tweak and debug, and I’ll keep posting as I do so other people can hopefully avoid these problems! I know that there are a lot options in Skeinforge that I haven’t even touched yet, so my problems might lie there. The Skeinforge documentation is the next thing I intend to read on the subject, and hopefully it will shed some light on what’s going on.

P.S. I will not be doing all of this in the next few days, however, because tomorrow at the crack of dawn I will be getting my wisdom teeth removed, and from there on out I will be either in pain, asleep, drugged, or not in a tinkering mood, so if you’re eagerly awaiting the results of my work, it’ll be delayed. Once I’m back among the living and I have my bot tuned up, however, I’ll try to document everything so others can follow along.


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