SOMOS 201 with DTM Sinterstation 2000

From: David K. Leigh (
Date: Mon May 12 1997 - 21:34:04 EEST

Hello All.

Just thought I would put my $.02 worth in on the new SOMOS material. We've
finished several builds so far, most of them successful. I tell you what,
a part as spongy as this SOMOS does wonders for measurement. If it's too
big, just keep squeezing those calipers. Anyway, on a more serious note:

* Parts are 80 Shore A Hardness
* They are a creamy white color.
* Part build - 10 watts laser, 135C part bed, 40C feed
* Layer thickness - .006"
* Shrinkage is approx. 2% in x and y, 1.5% in z
* Ideal for gaskets, seals, gromets, bushings, hoses, and ergonomic covers

Some Advantages
* You don't have to build master, tool, and cast urethanes for "rubbery"
        (Therefore turn around time and cost are significantly less)
* Complex internal features are achieved without having to deal with
difficult cores in mold
* Build rate is very good
* Recyclability of powder seems to be very good (there is a slight
yellowing after processing)
* Good warmup and cooldown (By good I mean very little)
* Strength is very good. You can pull the heck out of a tensile bar
without it breaking.
* The parts are suprising durable, and appear to be quite accurate
* I've done .050" wall thickness

Some Disadvantages
* Due to the softness, the glass beads in your bead blaster can penetrate
and discolor part.
* Can build up a static charge on roller, collect powder, and wipe out your
* Haven't found anything really good to coat it with, therfore surface
tends to be "powdery"
* Due to high laser power, beam offset is large. Thin wall and Thick parts
use different params
* Downward facing features are not as crisp (nothing new in rp)

If you are curious about the stuff, let me know. We're still on the
learning curves ourself. In summary, I think this material is a step in
the right direction for rp. It is truly unique in the rp community.
Materials are always an issue in manufacturing, and when rp cannot
simmulate those materials, marketshare is lost. I think we've always felt
that the rp process with the best variety of materials would be the choice.
 I mean, on Star Trek, they don't have to use a different replicator for
appetizers and desserts. So, I think this material will add marketshare to
the rp community. This is not a technology that splits the market, but
adds to it.

David K. Leigh phone (817) 742-1822
Harvest Technologies fax (817) 742-0053
Rapid Prototyping Services

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