Sunday, January 26, 2014

Working on the Lifter and more computer work

The Lifter Mechanism

This week I started working on the lifter mechanism that will give R2 the ability to show off the Life Form Scanner and Periscope.  Another builder in Sweden has a very clever design that has great potential.  

The trick is in Sweden everything in metric.  Replicating the parts in a non-metric country is a bit of a challenge!

Since he was kind enough to give me the files in STL format, my Ultimaker 3D printer and its CURA software can print most of the parts with ease.  However for something like this, I am not sure plastic is the best material.

To make the parts in aluminum, we had to work a bit harder.  Lars was kind enough to make the plans in DXF format, even though he had them all in Solid Works format.  Solid Works, which I have the Academic Version, does not allow you to have the latest Service Packs.  So, I could not view his files since he had a newer version.  Anyways, asides Solid Works proving to be more an obstacle than an effective CAD tool, we switched programs to keep making progress.

Then it was math word problems.  In the USA, all of our materials are in Imperial.  We can't go to the metal supply store and buy 5 mm thick material.  The closest I had was 1/4 inch, which when measured, turned out to be 0.24 inch thick.  That converts to 6.096 mm.  For each part, I would have to mill away 1.096 mm of material.  Sounds easy now but at the time, making all the tweaks in vCarve Pro and remembering to convert to metric...busy day of math problems!  

The bracket pieces are currently bent but I want my welding friend to touch that up a bit.  

The remaining parts are hard to source in the USA.  The gear I found, but the Module 1.0 15 mm x 15 mm rack is proving to be a bit more of a challenge.  Once I do get hold of the rack piece, I believe that will need some additional machining too.  Since that is steel, the equipment I have access too will not be able to cut it.  I'll need to recruit some help from a local shop for that.  The servo, shaft adapter and motor are all ordered and en route!

More Intel NUC progress!

The new power converter was put to the test this week!  Thanks to Intel replacing the NUC with a newer model that had the power connector, I tried it out.  

The HDMI to VGA adapter that went bad was replaced under warranty (despite having to email incessantly to C2G and Tiger Direct to get them to SHIP THE REPLACEMENT.  I can't give either high marks for customer service on this one.)  

I ran on battery power for 25 minutes before shutting down, happy that there were no hiccups with the converter.  According to the technical specs, the NUC will draw 13 watts at idle, 27 watts at load.  I've been consulting with some electronic minds to get an idea on the best battery and size to consider for powering this PC.

Sunday, January 12, 2014

3D printing an adapter piece

Tonight I finally got around to printing the part I needed to provide airflow to the NUC's power converter.

I own SolidWorks (Academic) 2013 and despite going thru many wonderful tutorials on, I could not create the piece to my satisfaction.

Here's the plan:  Take an old CPU cooling fan from an old Pentium Pro server and create an adapter piece so it can sit on top of the power converter enclosure.

It sounds simple!  The fan is a 50mm square and the enclosure is 43mm wide.  I had several ideas on how to do this and I settled on one where two tabs would extend out from below the piece, so it could straddle the enclosure and be attached from outside.  I'd leave the outside tabs intact, without a mounting hole, since I was not sure the best place for it to rest.

Several of my Ultimaker printer friends mentioned how quickly and easily they create things in SketchUp 2013.  After viewing the video tutorials on (a fantastic resource!), I started working on my drawing...

The biggest complaint I have with SketchUp is when creating circles, you can key in the distance you want.  The small holes are 4mm each, however the software, for whatever reason, enters in radius.  Also, resizing an existing object is a bit less intuitive, requiring you to "rescale" it, and if the object has been extruded (thickness added), you have to make sure both sides of the hole are selected.

In short, I struggled to make my simple part despite the "easy" interface.  In both SolidWorks and SketchUp.  Why?  I think while watching the tutorials, I had my mindset on what I needed to make versus learning the principals well.  In short, the impatient learner.

Once I had the part made, I had to Export it into a format the printer's slicing program, CURA, could use.  The only modification I had to do was flip the part upside down.

Just over an hour later, I have the part completed.

Next up is to see how the fan fits on it.  It fits perfectly.

Now I can drill and mount this piece as needed!  

The Ultimaker 3D printer is proving to be a very useful tool in droid building.