More Revolution XL successes and foibles

I spent a lot of time trying to figure out how best to tune my settings to create various objects.  For example, printing a vase is a simple matter.  No retraction is required and no stringing can happen.  Other parts can be more challenging.  Probably one of the most challenging prints is a model of the Eiffel Tower, something that I aspire to print correctly soon.

My 3D printing adventures were interrupted by a failure of my X-truder, one of the more innovative features of the RXL.  Nathan, head engineer at QU-BD sent me a replacement and I wired it in and sent him back the broken one.  To my dismay, when I tried it out, I saw that the extruder fan was not working.  I ran a continuity test that ruled out a problem with the cable and surmised that the problem had to be with the fan itself.  I ruled out a polarity problem because I presumed that the fan would just spin the wrong way.  As it happened, I had a replacement fan on hand (intended for another project) and so I disconnected the non-working one (which I prematurely dissected) and replaced it with the new one.  To my frustration and astonishment, the new fan did not run.  Now, totally confused, I reversed the polarity of this DC fan and voila! it worked!  Even Nathan at QU-BD was stumped.  He later told me that he tried to reverse polarity on several fans in the workshop.  Some spun backwards, some did nothing.

So I was back up and running -- that is until my next self-induced mishap.  Noticing that a certain print was going to go on longer that my filament spool, I devised to wait right until the last of the old filament got sucked down through the extruder and then I would immediately feed the new filament through.  This did not work out as planned.  The old filament became so lodged in the extruder that I had to disassemble it to get the filament out.

Once everything was back together, I made a personal vow never to try such a dopey move again.  My next foible was unexpected.  I assumed that scaling an STL file in Slic3r would be a simple matter.  It seems to be a bug with Slic3r itself.  Here is the original Koch Snowflake vase next to a 2X scaled version:

The one on the left came out perfectly but the one on the right had holes and imperfections around its widest part:

At first I thought it was a printing fluke, but it happened a second time.  I will need to research this problem.

The only other new thing that I tried was a new type of filament, namely Taulman 645 Nylon.  It really is quite amazing.  It is both flexible and incredibly strong.  Here is the same vase being printed in Nylon:

The resulting printed part is very resilient as you can see here:

Now, onto the Eiffel Tower!