Re: Bubbles in Resin Vat

From: JP Harrison (
Date: Thu Mar 29 2001 - 20:55:26 EEST

We had this discussion at the 3D Systems User's Conference. Also, try changing your dip velocity and acceleration form .2 to .1.


James P. Harrison
Director Of Operations
3Dimensional Engineering
2991 North Powerline Road
Pompano Beach, FL. 33069
Phone: 954-972-9906
Fax: 954-972-8903
  ----- Original Message -----
  From: Allan E W Rennie
  To: Rapid Prototype Mail List ;
  Sent: Thursday, March 29, 2001 12:43 AM
  Subject: FW: Bubbles in Resin Vat

  This message has been sent on behalf of John Male who is also having problems (similar to other list members) sending to the list. Please direct all enquiries to John at AND NOT TO THE SENDER OF THIS EMAIL!!!!!!!!


> -----Original Message-----
> From: John C Male
> Sent: 28 March 2001 18:23
> To: 'Jeff Toole'; Rapid Prototype Mailing List
> Subject: RE: Bubbles in Resin Vat
> Jeff,
> Bubbles form during the deep dip stage of recoating used with the doctor
> blade. When I had looked at this (a few years ago now - pre-finepoint
> supports) the bubbles were pushed away from the part, and it was rare for
> the bubbles to be trapped. Zephyr doesn't do a deep dip, so the bubbles
> are not created to start with.
> I don't have a definite solution for getting rid of bubbles, but would
> suggest trying just using deep dip for the first 6-7mm of z (however tall
> you make your supports), if you aren't doing so already. This should stop
> the formation of a lot of small bubbles. Once bubbles have formed in the
> solid part, they tend to breed more bubbles above themselves.
> During my research I had also developed a non contact imaging system which
> looked at the liquid resin surface, and determined if there were any
> disturbances (excess resin, bubbles, SL debris) on the surface. As
> imperfections on the surface of the resin being cured in place is one of
> the causes of build crashes, being able to spot these gives you the
> opportunity to do something about it - switch to deep dip for example,
> which will build past the problem area (although it may introduce
> bubbles). I should say that this hasn't been commercialised (and I am no
> longer directly working full time on RP), so some work still needs to be
> done, but feel free to get in contact if you would like some more
> information.
> John Male
> Advent Communications Ltd
> (ex CRDM)
> -----Original Message-----
> From: Jeff Toole []
> Sent: 28 March 2001 16:55
> To: Rapid Prototype Mailing List
> Subject: Bubbles in Resin Vat
> I have a problem with bubbles in the resin during builds. I know it
> sounds a
> little silly at first, but this does have consequences in part quality and
> personnel utilization (someone has to be on "bubble popping patrol" at the
> start
> of builds).
> I am running SLA-250's with Doctor blades and SLA-500's with Zephyr
> blades.
> Resins are Somos 7100/7110/7120, 8110/8100, and 9100. Supports are
> Finepoint
> via Lightyear 1.1 w/ SP1.
> The problems are twofold. First, during the initial support building
> phase, a
> lot of bubbles can knock out supports and cause "mounding," leading to a
> crash.
> Second is the problem of small bubbles becoming cured into the parts.
> This
> seems to happen most with the Doctor blades as the tend to comb larger
> bubbles
> through the Finepoint supports to create ever smaller bubbles. These
> small
> bubbles are virtually impossible to clear from the vat once they have
> formed.
> This doesn't seem to occur with Zephyr blades as a single pass (maybe two)
> usually clears all bubbles.
> Does anyone else have trouble this? Has anyone come up with any good
> solutions
> for it?
> For more information about the rp-ml, see

  Allan E W Rennie
  Research Engineer
  Centre for Rapid Design and Manufacture
  Buckinghamshire Chilterns University College
  Queen Alexandra Road
  High Wycombe
  Bucks HP11 2JZ
  Tel: +44 (0)1494 605085
  Fax: +44 (0)1494 538593
  Mob: +44 (0)7930 431469

For more information about the rp-ml, see

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