January 2022

Our first meeting of 2022, though riddled with technical problems for the first time ever, was still quite a success

 Paul gave an interesting presentation describing the 3D Resin Printing Process.

It begins with a 3D model that is converted to an STL file so the slicer program can create the g-code that the printer reads.  Paul uses an Elegoo Mars 2 Printer and the Lychee Slicer Program (free version available).  The slicer predicts the print time material used and material cost.  The printer needs to be in a warm environment and the action of printing is executed by continuously dipping the build plate down into the resin bath.  The printed part is built hanging off the underside of the build plate.

When done the part(s) must be washed to remove the unused resin.  Paul does this in a pickle jar filled with 99% Isopropyl Alcohol.  The parts with printed supports are swirled around in the alcohol for a few minutes.  The supports are then removed and the parts being kept are dried in a paper towel and then put back into the alcohol and swirled for a couple more minutes.  To keep the bad smell from the process under control Paul puts the discarded supports and used paper towels in a zip lock style bag.

Once clean the parts need to be cured to harden them and he uses a purchased Elegoo Mercury Curing Station to do this.  Curing takes about 6 minutes in this station.  After this they are ready to be painted, if desired,  and used.

Alan gave a presentation on 3D printing with filament.

His printer is a JGAurora A5 printer with a heated glass bed.  It will print in various materials but Alan uses a PLA or Polyactic Acid, a biodegradable and environmentally friendly thermoplastic made from corn or sugar cane.  In the case of the gun carriage model used in this presentation the filament was a PLA/Wood mix. 

He begins by creating his model with the free hobbyist version of Fusion 360.  This file is then exported as an .stl file that his free CURA slicer program can read and convert to g-code which is what the printer reads.  The slicer predicts the print time material used and material cost.

In preparation his printer bed must first be cleaned with Isopropyl Alcohol and then levelled to the printer nozzle when hot (60°C or 140°F).   The filament is fed from the reel through the gear drive to the 215°C or 419°F heated nozzle.  The g-code is loaded and printed.  When done there is some cleanup (filing and sanding) and the part is ready to be painted, if desired, and used.

Info on links to free programs and websites with free STL files here:

mson_-_free_3d_info_links.pdf
File Size:	184 kb
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Kurt showed us how to make two different coils of rope.

The first (above) was a cheesed or flat coil of rope to be laid on the deck.  The method is explained in the four slides.
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The second type (below) was a coil of running rigging rope that would hang from a belaying pin.

Ian gave us tips on how to display our models LIVE on a virtual (ZOOM) platform.  It is necessary to keep both the model and camera fixed and steady for clear and crisp detailed viewing.  A camera with a tripod stand plugged into a nearby computer is required.  An auto focus zoom type camera would be a tremendous aid to the process.  The model should be mounted on a rotating pedestal or turntable.  If manually rotated your fingers may be in the image.  There are remote turntables available (on Amazon) at a cost or you might consider rigging yours with a string (see below).  Good lighting is important and using a board background to help deflect the light onto your model and hide any background viewing distractions is a worthwhile consideration.

Images below show, in concept, how to convert a standard hobby painting pedestal into a remote turntable.

Robin delighted us with something different.  He had a metal V2 Engine kit he had decided to work on and showed us the results.