…code, cg, electronics, 3d printing…

Onto my last week of creativity!  Back to week 3…

Days 26-28, Thurs -> Sunday, December 2013

Well, the last three days were a bit of a creative fail, in a way: Thursday I was just exhausted after work, friday my best friend flew into town as a surprise for my… birthday party on Saturday.  So while the last to days were very enjoyable, they weren’t necessarily ‘creative’.  Unless you count a beer-tasting birthday party as creative

Day 25: Wednesday, December 4th, 2013

Almost printed…

One minute shy of the ten hour mark, the below print finished (on my Makerbot Replicator 1).  I should have known better though, and modeled in my own support columns for the overhanging clasps:  As expected they broke free at some point during the print, and it failed.  That being said I still cleaned it up and snapped a pic of it on my arm.  I won’t re-print it:  I don’t like it that much.  But it was a fun exercise in the scan -> model -> print process I’d not tried before.

Day 24 : Tuesday, December 3th, 2013

Moar Meshmixer

It dawned on me after finishing the sculpt yesterday:  It would be impossible to actually get ones arm in that thing, based on the size of the wrist.  Tonight, I did a new sculpt that should be far more… ergonomic, when it comes to wearing it:

Hopefully can start printing it tomorrow!

Day 22: Monday December 2nd, 2013

Meshmixing Skanect

Over the weekend I’d bought a used Kinect, and had scanned my Makerbot Replicator as a test… although not a very useful test.  During that process I learned that Skanect likes to crash pretty often on my Macbook Air.  I figure I need more horsepower:  I thought I may be able to get gpu acceleration working, but after checking the Skanect Google Group, I was told my grahics card (GeForce 320m, 256 meg) isn’t supported

Regardless I thought I’d try a more complex subject:  My wife’s arm.  I tried several times walking around her holding the scanner while she held her arm up, but I just couldn’t get a good scan.  So I got her on a spinny-chair and had her spin in a circle:  Success.  However, I can’t get any scans to work on “high” quality:  It just crashes at some point.  But medium and low quality seem to work.

Here’s the result in Skanect, and later in Meshmixer:  I imported the scanned mesh, smoothed it, and started drawing patters which I later extracted, extruded, and detailed.  My hope is to get this mesh into Maya where I can split it in half for 3d printing.

The Mrs's arm in Skanect

Forearm bracer in Meshmixer

About nine months ago, I blogged about how the cable to my Makerbot Replicator’s heated build platform (hbp) fried.  Their support was really responsive and shipped me out a new cable that fixed the problem.  Well, it fried again.  And if something breaks twice, I start to think about how I can make it ‘better’.

Took me a while to understand what went wrong, since from the top it looked just fine:

But after removal, the problem was plainly visible:

After checking the forums, there were several suggestions from knowledgeable users to make a separate connection for the main positive and negative leads, using 14-16 gauge cable.  When I went to the local electronics store, I could only find connectors in 18 gauge, or 12.  I went with 12.  Which is huuuuge for this, but hey, sometimes you have to work with what you have 😉

The first step was to use a Dremel cutting wheel to hack off the positive & negative connectors:

Since the connector I purchased wasn’t long enough to reach the Mightyboard, I had to solder on some (slightly smaller) extensions.  This also shows off the actual connector point itself:  This allows me to disconnect the whole hbp from the Mightyboard, for future removal if needed.  This section sits directly under the hbp itself (when final cable routing is performed).

I ended up wrapping the whole thing in heat-shrink tubing.

The next tricky bit was soldering the 12-gauge wires to the hbp itself.  To make room, I bent the left-most lead over.  And to keep all the twisted strands from shooting all over the place, I tied a noose around each using the wire from a twist-tie:

Next came the soldering:

After which I removed the nooses.  Finally I wrapped them up in electrical tape, and reconnected everything on both ends of the cables (no pic of the Mightyboard connection, but it’s pretty much the same as before, just with two bigger cables running into it):

I was a little scared to fire it up and start heating the platform, but it performed flawlessly.  And with the larger gauge cables, heats up faster too.  If things are still working nine months from now, I guess the fix worked 😉