From: David K. Leigh (dkleigh@harvest-tech.com)
Date: Wed Apr 30 2003 - 16:57:12 EEST
You are getting heat from somewhere if you are seeing it jump that high. If
the "heat" is being caused by scanning in front of the IR sensor, it will
actually lower the effective bed temperature because the reading will be
greater than the setpoint causing the heater to turn off.
Realize there are multiple elements in the control scheme and several
heating zones. I'd suggest you check the following:
1. Left and Right feed temp. This can cause an elevation in the part bed.
2. Part cylinder temp.
3. Part piston temp.
4. Stable control loops. By this, I am implying an "open" loop in which
the control source (IR or T/C) are not controlling the temperature. You can
open the status window and look at all of your temperature sepoints and
actual temperatures. This will alert you to an issue where a heater is
"running away."
My guess is that you've got your piston or cylinder temperature turned on
and this is causing the part bed to melt. I'd suggest you set all of your
temperature enabled setpoints to 0. This will turn off the heaters. That
way, you are only controlling the part bed with your IR sensor.
Good Luck.
********************************************************************
David K. Leigh (254) 933-1000
Harvest Technologies, Inc. fax (254) 298-0125
Rapid Prototyping Services www.harvest-tech.com
-----Original Message-----
From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi]On
Behalf Of #GUI WEE SIONG#
Sent: Wednesday, April 30, 2003 3:36 AM
To: rp-ml@rapid.lpt.fi
Subject: SLS part bed temperature
I am presently doing test sintering on polycaprolactone (PCL) on the SLS
machine Sinterstation 2500.
I am working at ambient temperatures of 30ºC.
I noticed that the actual part bed temperature rises to more than 60ºC after
some time, although I set the part bed temperature at 30ºC.
As PCL has a melting point of 60ºC, the samples melted.
Is there any way we can control the temperature at around 30ºC or possibly
switch off the heater of the SLS machine?
Please advise.
Thank you
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