A Modest 3D Printing Project

As luck would have it, the new edition (March/April 2017) of the
MBSI "Mechanical Music" glossy arrived today, containing an excellent
article by Dr. Wayne Finger on using 3D printing to replicate hard
(or impossible!) to find parts for our wonderful mechanical devices.
He gives an excellent overview of the process, and the "pros and cons"
of its application to the field.  I highly recommend it to anyone
considering this technology for either personal or business endeavors.

I had just yesterday produced a "proof" replica of the Universal pouch
carrier ring about which there has been much discussion on MMD of late.
This was fabricated using a CAD file created by good friend John
Tuttle, as he and I have been discussing using 3D printing techniques
for quite a while.  Even though this part is relatively simple, creation
of the files, in general, as noted by Dr. Finger, is not always easy.

The attached photo shows the part, side-by-side, with an undamaged
original, also supplied to me by John.  I am returning both to him for
evaluation and testing, but all dimensions between the two seem to
agree within 0.002", so I don't anticipate any issues.  I used the
filament that was already in the printer, a medium gray color but there
are dozens of colors to choose from, including white.  The material is
"PLA" plastic, a frequent choice for 3D printers.  I also have "ABS"
plastic available, but it is a little more difficult to work with, and
for this application, the PLA seems adequate.

As is typical for 3D printers, the actual layer structure will be
evident in the height build dimension (Z axis).  This effect can
sometimes be lessened in a post-processing step by "painting" the
surfaces with a solvent such as acetone.  This "amalgamates" the
surfaces and makes the individual layers less visible, but it is
difficult to achieve, in a hobby priced machine, total smoothness.

In this case, it's probably a desirable feature anyway as the pouch
glued to the bottom surface will probably adhere better and the outside
surface will probably have a better "grip" on the pouch well.  I did
use a solvent on the inside and outside edges to judge the effect, so
you will notice a slight "rounding" of them, but they were as sharp as
the original when it came off of the printer bed.

The slight "ring" visible on the inside and outside surfaces at about
the mid-point in thickness, I believe happened when I accidentally
bumped the machine while it was printing.  It's cosmetic only and has
no effect on the functionality I'm sure.

This particular printer is made by Tinkerine (www.tinkerine.com) and
is on the high end of "hobby" grade machines, retailing for $1899.
Cheaper machines are available, but this one is extremely easy to set
up and use, and I have not yet experienced a "failed" print.  Also
attached is a video showing the actual printing process underway.  It
runs about 10 seconds.

I applaud Dr. Finger's willingness to share the CAD files he created
and encourage others to do the same.

John Grant

 [ http://www.mmdigest.com/Attachments/17/03/04/170304_124909_Universal%20Pouch%20Ring%20-%20Original%20and%203D%20Printed%20Replica.jpg 
 [ http://www.mmdigest.com/Attachments/17/03/04/170304_124909_Universal%20Pouch%20Ring%20being%203D%20printed.mp4 

 [ If the MP4 video won't play within your web browser, download it
 [ and then launch a local video player such as Media Player.  -- Robbie