Re: same song - Layer Thickness reply

From: Lee Humphrey (Lockheed-Martin  Corporation)
To: RP-ML, Elaine Hunt (Clemson  University)
Date: Saturday, January 21, 1995
Subject: Re: same song - Layer Thickness reply
To: rp-ml@cs.hut.fi, persall@eng.clemson.edu
I do not use thin layers very much.  Probably 80-90% is at .010" on 
the SLA250(5149) and 100% at .006" on the SLA500(5180).  Main reason 
is time vs need. There will usually be 1000 to 3000 layers in a SLA500 
build and the process time will go from 4-5 Days to almost 2 weeks for 
a single build.  In the least 5500 hours on the SLA500, halving the 
layers would have ment only half the runs in the same time period.  We 
are mainly interested in going the other way to increase throughput.

On the SLA250 I have easily and reliably built at .005" with 5149 
resin.  I have have limited success with .003".  The success window is 
much smaller and very geometry dependent. Success with .004 but that 
is not much different than .005".

For productivity reasons and the larger types of geometry I usually 
work on, I almost always use the standard .010 and .006 for the 250 
and 500 machines.

My main concern for the SLA500 is in tank resin stability which has 
not been good this past year but I am hopeful for the new year.  The 
5149 in the SLA250 has been an extremely stable, predictible resin.  
it may warp alittle more than others but it has been very predictible 
for 2 years which is an eternity in this field.

lee_humphrey@ccmail.orl.mmc.com