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> -----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
> Bubbles form during the deep dip stage of recoating used with the
> 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
> the bubbles to be trapped. Zephyr doesn't do a deep dip, so the
> 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
> you make your supports), if you aren't doing so already. This should
> the formation of a lot of small bubbles. Once bubbles have formed in
> solid part, they tend to breed more bubbles above themselves.
> During my research I had also developed a non contact imaging system
> 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
> 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
> longer directly working full time on RP), so some work still needs to
> done, but feel free to get in contact if you would like some more
> John Male
> Advent Communications Ltd
> (ex CRDM)
> -----Original Message-----
> From: Jeff Toole [SMTP:firstname.lastname@example.org]
> 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
> personnel utilization (someone has to be on "bubble popping patrol" at
> of builds).
> I am running SLA-250's with Doctor blades and SLA-500's with Zephyr
> Resins are Somos 7100/7110/7120, 8110/8100, and 9100. Supports are
> 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
> Second is the problem of small bubbles becoming cured into the parts.
> seems to happen most with the Doctor blades as the tend to comb larger
> through the Finepoint supports to create ever smaller bubbles. These
> bubbles are virtually impossible to clear from the vat once they have
> This doesn't seem to occur with Zephyr blades as a single pass (maybe
> usually clears all bubbles.
> Does anyone else have trouble this? Has anyone come up with any good
> for it?
> For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
-- 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 Email: email@example.com --------------------------------------------
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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