Archive for January 2016

Turning up the heat

Turning up the heat - 3D printing blog post, Kevin CaronIn these “Model T” days of 3D printing, which we will someday look back at fondly once everything is figured out, I spend more time than you might think tweaking, replacing, fixing things to make my printers work better.

You’ve read about a number of these changes, especially on my 8-foot-tall Cerberus 3D Gigante 3D printer, which Steve Graber made after I asked him, “Can you make a really big 3D printer?”

I wrote in a previous post about trying to create a heated bed on this monster, with its 34″ print tray. Well, the heating pads just weren’t cutting it, so I came up with an entirely different solution and this time – I’m knocking on wood right now – I think I’ve figured it out ….

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Chaos reality: 3D printer has a mind of its own

Cuddle - a 3D printed sculpture by Kevin CaronWorking with 3D printing in this “Model T” period means dealing with all sorts of surprises. All of them are probably maddeningly logical – these printers are run by computers, after all – but sometimes it’s hard to figure out why.

That was the case with a recent 3D printed sculpture I’m calling Cuddle (my wife keeps calling it Huddle – go figure).

Although the final print came out beautifully (except for the color, but that’s another story!), my Cerberus 3D Gigante 3D printer decided to get there in a mighty odd way ….

Admittedly, these prints are big. This particular one, although it’s far from as large as several I’ve done, is also complex. I had tried to print it three times before I reduced it in size and resliced it again. This time the sculpture finished printing, not even threatening to lift off the print tray, a problem I have with these large prints.

But as it printed, I noticed that the printhead was tracking really bizarrely. The head wouldn’t go around each “tower.” It didn’t go around the exterior of the entire sculpture and work its way in, either. It just seemed to hop from one area to another what appeared to be randomly.

Cuddle - void detail - in a 3D printed sculpture by Kevin CaronOf course, it wasn’t random – it’s a computer! – but it sure looked that way. Steve Graber, my 3D printing guru and the genius who built the Gigante and its little cousin the Cerberus 3D 250, even commented on the printhead’s chaotic path. Most of what it created, however, looked fine.

What was particularly strange, though, was the voids it created both in the bottom of the piece (below, right) and – thank goodness – on certain interior walls (left).

I’d learned from my experience with Sunscraper, the big yellow sculpture that I talked about in my last post, that I wanted to be very careful with interior walls after Kisslicer, the slicing program I use, decided to just eliminate them where they overlapped in the design. So this time I made sure that the walls didn’t touch but only butted up to each other.

Still, the program decided to leave really odd openings on either side of the walls on the bottom of the sculpture for no apparent reason. Fortunately, it has not seemed to jeopardize the sculpture’s structural integrity.

Cuddle - detail of voids in bottom of the 3D printed sculpture by Kevin CaronThe “windows” it made in the interior walls were a little more concerning, but ended up not making a difference in the print structurally or aesthetically because no one can see them.

Interestingly enough, the printhead would come up one side of the window, turn around and go back, then come up the other side and turn around. So it wasn’t jumping the space, although it did eventually “heal” the wall over them.

Again, the good news is that it didn’t seem to affect the sculpture in any meaningful way. You can’t even see the interior voids now that the sculpture is done.

What caused these aberrations? I don’t know if I’ll ever know, but I’ll continue to try to find ways around them.