Hey Kevin, looks like you are getting very close. Go look at the pictures
in the sergent engineering groupsio page “Treeing 3D prints”. Look at the
IMG_1095.jpg picture. All the 3D models are designed so they can be 3D printed
with no support structure. I’m convinced that you don’t have to go to investment
cast metal with the resins that are available today. You may have to modify the
coupler designs slightly to beef up the cross section of the shanks where the
hole that receives the “rivet” from the bottom part fits. Also, all my 3D model
files have pre-distorted knuckle hinge pins that allowed the final product to
come out correctly on my printer. You’ll have to modify the design in that area
to give predictable geometry from your printer. Also, a good UV curing process
is very important to get usable parts whether you are investment casting or not.
Sent: Monday, January 06, 2020 5:31 PM
Subject: Re: [Sergent Engineering] Couplers
- I did use dry graphite when I put the ball in, and it helped. The
knuckle could certainly use some of it. I'll give that a shot on the next
set I assemble.