Friday, June 27, 2014

3D Printer

On a boat, there are plenty of plastic things.  The material is corrosion resistant but they have a limited lifespan.  Now comes the 3D printer.  I have wanted one of these for a while and had the perfect job to justify it.  When the rigging was replaced in Mexico, the turnbuckles were longer and wider so I was not able to reinstall the aluminum covers. 


The tubes had plastic tapered plugs in the ends that fit the cable and stud ends.  I was looking to fabricate the plugs out of PVC rod on a lathe but since I had to make 2 halves that would have to bolt together, the job got very complicated since the rod would have to be cut down the middle, tapped and screwed, then turned on the lathe.  Possible but definitely time consuming.

Along comes 3D printing.  I have been putting off the purchase for a year and finally bit the bullet.

There are some expensive printers out there but in the end, plastic extrusion is plastic extrusion.

I chose to go with the Solidoodle 3.

 

In a sense, you are buying a kit.  Do not expect it to work directly out of the box.  They need to be tweaked and calibrated.  There is a steep learning curve to operating them but isn't that what it's all about anyway.  I have had no electronic problems except when the USB cable got yanked out of the controller board and I had to rebuild it.  Otherwise it has been the mechanical issues such as :Printbed not flat, printbed rivets loose, Y-axis belt tension calibration, extruder feed calibration (firmware), extruder feed calibration (software), filament quality problems, extruder mount cracking, spool feed friction, extruder clogged, and extruder servo clicking.

The thing that I liked about this design was the print size of 200mm and that the bed moves only in the Z-axis and the price.  I think that designs where the printbed moves in the Y axis also have inherent problems attaining maximum print speed due to the inertia of a moving printbed.   I also like the MakerBot but it cost $2200 vs $800 for the Solidoodle and is of the same design.  I paid extra for a Kapton printbed which was a total waste.  The heated printbed, however, it a must.  Plastic will not stick otherwise.  An enclosure is also a must.  I like my plexiglass enclosure because I can see everything happening.  A metal case does not permit this.  It also makes for a fun first project.

Most everything is open-source but a from scratch build is not without pitfalls.  I could attempt one now that I have learned on this one but would have wasted plenty of time building one myself and not have had as good a printer.  You also need to have access to a 3D printer to print the major parts to make a 3D printer. (Catch 22) .

The Solidoodle was inexpensive but lacked manufacturing quality control.  There were loose rivets, loose belts, loose extruder frame and needed calibrating when it arrived.  Without some type of enclosure keeping the heat in and drafts out, the parts cool unevenly and warp.  Solidoodle makes a model that has a metal enclosure but I wanted a clear plexiglass enclosure to be able to look at this thing while it was printing.  This was a good move as so much of the troubleshooting required watching with a magnifying glass as it printed.  I was able to get it to print some mounting pieces for the plexiglass that I wanted to put on it.  Then it broke again for 2 weeks.  It was shredding the feedstock plastic.  I tried everything and as I was about to give up and chuck it in the closet, I tried a different spool of material and it worked.  I think that the cheap plastic has recycled content in it which has varying melting points causing irregular extruding.



Next, what to print!




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