RE: Beefy SLA part warpage question.

From: Luper, Harold (HLuper@SOLIDIFORM.com)
Date: Fri Jan 07 2000 - 00:13:24 EET


I have had this problem building "beefy" ACES parts as well, with all three
machines and resins we've had over the years; an SLA 250 running 5170, SLA
3500 running 5190, and our current machine, an SLA 5000 running 5195. I've
tried different orientations in the PCA (like face down with blocks under
the corners) to no avail. I haven't tried curing the part on the platform.

I have even seen parts where there was less "curl" in the top of the part
than there was on the bottom (the part was actually thicker in the middle),
especially off of the SLA 250.

Could this be caused by the effect of the resin being cured from the top for
every layer, and/or that the shrinkage occurring in each layer is cumulative
in the build? In other words, if layer #1 shrinks, then layer #2 attaches
and shrinks, layer #3..... and so on, wouldn't that pull up the edges?

Thanks,

    Harold Luper http://www.solidiform.com
    Prototyping Specialist email: hluper@solidiform.com

    Solidiform Incorporated Phone: (817)-831-2626
    3928 Lawnwood Fax: (817)-831-8258
    Fort Worth, Texas

-----Original Message-----
From: Bill Cannon-WM [mailto:cannon.wm@pg.com]
Sent: Thursday, January 06, 2000 3:14 PM
To: tbush@prototechengineering.com
Cc: rp-ml@bart.lpt.fi
Subject: Beefy SLA part warpage question.

I too have had this same problem. The diameter of my part was approximately
16
inches and the thickness was roughly .75. The next time I built the part I
cured it with the platform, supports and all. This worked. I have an SLA
5000
and use 7120 resin. Did I just get lucky the second time?

Bill Cannon
---------------------- Forwarded by Bill Cannon-WM/PGI on 01/06/2000 04:08
PM
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From: Tim Bush <tbush@prototechengineering.com> on 01/06/2000 03:13 PM

To: rp-ml@bart.lpt.fi
cc: (bcc: Bill Cannon-WM/PGI)
Subject: Beefy SLA part warpage question.

Dear SLA Users,

Recently, we built 14

For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/



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