Thought I would start a new thread since we are now talking Metal. to be specific we are talking a Shape ways Process they call “Steel”
this is actually a stainless steel and nickel mix if I understand correctly. it is done by distributing a binder to a layer of metal powder,
followed by additional layers of metal powder and binder. the end result is sintered to bind the material together, resulting in shrinkage.
Below is my current cad file;
it shows two cross head locations because some folks have expressed an interest in an economy conversion kit that would use the existing driver
spacing. I am working towards doing the correct driver spacing .
the red features in the above drawing are the original C-19 locations
Some of you may have seen this project in other threads on Bachman C-19. So with interest in the project I bite the bullet and sent a couple of files in for metal printing.
the important part of this project was to find out what the results turned out to be dimensionally. I had up scaled my models by 1.03%, and this appears to be a good number.
the shape ways site is none to specific about the amount of shrinkage saying that for this material it could be up to 5%. why this material and not brass? simple economics my friends.
doing these with lost wax via Shape ways was more than twice the cost. and the added issue was that the main rod was to long to do in lost wax.
I looked at another vendor for the lost wax, but I would need to purchase 12 sets up front, at an unknown cost. while shrinkage is more stable at 2.5%.
if something was wrong I would have a bunch of scrap brass on my workbench.
from the above charts you can see what I wanted and what I got. the only issue is the length of the main rod
as it is 1/16" too long. and this length is important. I will adjust the file for the next print by artificially
adjusting this dimension, and leaving the hole out for later drilling. the Laird Cross head is good to go!
Disclaimer: the above results relate directly to the parts printed. your results may vary.
AL P.