My idea was not 3d printing the mold, but to machine the mold, that to from high density steel material. I am also not sure right now whether it is possible to get the machining codes from an stl file. During the process, I have learnt that it is possible to extract the mould design from the part design in openscad. Though some more work needs to be done to make it simpler On Wed, 8 Mar, 2023, 1:02 am andrew goh via Discuss, < discuss@lists.openscad.org> wrote: > > > > ---------- Forwarded message ---------- > From: andrew goh <gohandrew@yahoo.com> > To: discuss@lists.openscad.org > Cc: > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > > I've been thinking about 3d printing molds, say for polyurethane foam > casting. > > I never quite put in the effort to do it. > > I'm a novice in this. > > I'd seem making 3d printed molds may be difficult as it is after all > rather soft materials, and that the expanding foam may expand so much the > mold could deform. > And that it requires a mold release, which i'd guess things that could be > tried could include shoe polish, baby powder, silicone oil (spray) etc, > silicone spray is actually used in metal molds i'd guess. > > that is actually the lesser of problems, but that i'm not sure how toxic > is the polyurethane materials after all MDI etc if it would necessitate > using a proper VOC respirator etc, quite expensive but may after all be > necessary. expanding foams are quite easy to buy say from construction > products businesses, e.g. for foam insulation etc. > no need for the speciality types, just that handling the chemicals I'd > guess would need quite some precautions, VOC respirator etc. > On 05/03/2023 20:37, Sanjeev Prabhakar wrote: > > Wow > > Great to hear that > > I have almost no experience of sand moulding, but we have made hundreds of > die casting moulds if not thousands. > > In Engineering we have designers who mainly work on expensive softwares > like nx , Catia, creo, autocad etc. > > It's very easy to make mould designs in these softwares, although I don't > work on that. > > Many times I show our designers that openscad could be an alternative for > some type of designs. > > But it seems they don't take me seriously and it's fine. > > I like openscad although till date almost no professional work is done by > me on this, but I intend to make few functions which could be useful for > professional use. > > > On Sun, 5 Mar, 2023, 2:20 pm nop head, <nop.head@gmail.com> wrote: > >> My father was a pattern maker, long before 3D printing was a thing. He >> made the patterns out of wood manually and had a set of rulers that were >> out by the contraction ratios of different metals, which I still have. >> >> On Sun, 5 Mar 2023 at 08:30, Sanjeev Prabhakar <sprabhakar2006@gmail.com> >> wrote: >> >>> That's a good idea, will give it a try in our next project. >>> >>> >>> >>> On Sun, 5 Mar, 2023, 12:59 am nop head, <nop.head@gmail.com> wrote: >>> >>>> You can print a PLA pattern that is the same as the desired final >>>> object but expanded by the amount the metal contracts and then build a sand >>>> or plaster mould around it. >>>> >>>> PLA can be burned out just as easily as wax. >>>> >>>> On Sat, 4 Mar 2023 at 19:24, Steve Schlaifer <steve@jetcafe.org> wrote: >>>> >>>>> You could use this as the start of a lost wax process. >>>>> >>>>> Steve Schlaifer >>>>> On Mar 3, 2023 at 4:07 AM -0800, Sanjeev Prabhakar < >>>>> sprabhakar2006@gmail.com>, wrote: >>>>> >>>>> Guenther >>>>> >>>>> I am not planning to do anything with this. >>>>> >>>>> I was just checking if dies can be modelled with this approach. >>>>> >>>>> In the process I found it is very complex right now to do something >>>>> like this. But lot of learning from this challenging work. >>>>> >>>>> >>>>> On Fri, 3 Mar, 2023, 3:38 pm Guenther Sohler, < >>>>> guenther.sohler@gmail.com> wrote: >>>>> >>>>>> it looks very nice! >>>>>> Whats your workflow like? >>>>>> apparently you cannot pour molten metal onto the plastic >>>>>> >>>>>> >>>>>> On Thu, Mar 2, 2023 at 6:45 PM Sanjeev Prabhakar < >>>>>> sprabhakar2006@gmail.com> wrote: >>>>>> >>>>>>> bottom mould completely done in openscad. >>>>>>> >>>>>>> <Screenshot 2023-03-02 at 11.10.21 PM.png> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> OpenSCAD mailing list >>>>>>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>>>>>> >>>>>> _______________________________________________ >>>>>> OpenSCAD mailing list >>>>>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>>>>> >>>>> _______________________________________________ >>>>> OpenSCAD mailing list >>>>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>>>> >>>>> _______________________________________________ >>>>> OpenSCAD mailing list >>>>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>>>> >>>> _______________________________________________ >>>> OpenSCAD mailing list >>>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to discuss-leave@lists.openscad.org >>> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org > > > > > ---------- Forwarded message ---------- > From: andrew goh via Discuss <discuss@lists.openscad.org> > To: discuss@lists.openscad.org > Cc: andrew goh <gohandrew@yahoo.com> > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >

 ---------- Forwarded message ----------
 From: andrew goh <gohandrew@yahoo.com>
 To: discuss@lists.openscad.org
 Cc:
 Bcc:
 Date: Wed, 8 Mar 2023 03:31:47 +0800
 Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds

 I've been thinking about 3d printing molds, say for polyurethane
 foam casting.

 I never quite put in the effort to do it.

 I'm a novice in this.

 I'd seem making 3d printed molds may be difficult as it is after
 all rather soft materials, and that the expanding foam may expand
 so much the mold could deform.
 And that it requires a mold release, which i'd guess things that
 could be tried could include shoe polish, baby powder, silicone
 oil (spray) etc, silicone spray is actually used in metal molds
 i'd guess.

 that is actually the lesser of problems, but that i'm not sure how
 toxic is the polyurethane materials after all MDI etc if it would
 necessitate using a proper VOC respirator etc, quite expensive but
 may after all be necessary. expanding foams are quite easy to buy
 say from construction products businesses, e.g. for foam
 insulation etc.
 no need for the speciality types, just that handling the chemicals
 I'd guess would need quite some precautions, VOC respirator etc.

 On 05/03/2023 20:37, Sanjeev Prabhakar wrote:

 Wow

 Great to hear that

 I have almost no experience of sand moulding, but we have made
 hundreds of die casting moulds if not thousands.

 In Engineering we have designers who mainly work on expensive
 softwares like nx , Catia, creo, autocad etc.

 It's very easy to make mould designs in these softwares, although
 I don't work on that.

 Many times I show our designers that openscad could be an
 alternative for some type of designs.

 But it seems they don't take me seriously and it's fine.

 I like openscad although till date almost no professional work is
 done by me on this, but I intend to make few functions which
 could be useful for professional use.


 On Sun, 5 Mar, 2023, 2:20 pm nop head, <nop.head@gmail.com> wrote:

     My father was a pattern maker, long before 3D printing was a
     thing. He made the patterns out of wood manually and had a
     set of rulers that were out by the contraction ratios of
     different metals, which I still have.

     On Sun, 5 Mar 2023 at 08:30, Sanjeev Prabhakar
     <sprabhakar2006@gmail.com> wrote:

         That's a good idea, will give it a try in our next project.



         On Sun, 5 Mar, 2023, 12:59 am nop head,
         <nop.head@gmail.com> wrote:

             You can print a PLA pattern that is the same as the
             desired final object but expanded by the amount the
             metal contracts and then build a sand or plaster
             mould around it.

             PLA can be burned out just as easily as wax.

             On Sat, 4 Mar 2023 at 19:24, Steve Schlaifer
             <steve@jetcafe.org> wrote:

                 You could use this as the start of a lost wax
                 process.

                 Steve Schlaifer
                 On Mar 3, 2023 at 4:07 AM -0800, Sanjeev
                 Prabhakar <sprabhakar2006@gmail.com>, wrote:

                 Guenther

                 I am not planning to do anything with this.

                 I was just checking if dies can be modelled with
                 this approach.

                 In the process I found it is very complex right
                 now to do something like this. But lot of
                 learning from this challenging work.


                 On Fri, 3 Mar, 2023, 3:38 pm Guenther Sohler,
                 <guenther.sohler@gmail.com> wrote:

                     it looks very nice!
                     Whats your workflow like?
                     apparently you cannot pour molten metal onto
                     the plastic


                     On Thu, Mar 2, 2023 at 6:45 PM Sanjeev
                     Prabhakar <sprabhakar2006@gmail.com> wrote:

                         bottom mould completely done in openscad.

                         <Screenshot 2023-03-02 at 11.10.21 PM.png>

                         _______________________________________________
                         OpenSCAD mailing list
                         To unsubscribe send an email to
                         discuss-leave@lists.openscad.org

                     _______________________________________________
                     OpenSCAD mailing list
                     To unsubscribe send an email to
                     discuss-leave@lists.openscad.org

                 _______________________________________________
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                 To unsubscribe send an email to
                 discuss-leave@lists.openscad.org

                 _______________________________________________
                 OpenSCAD mailing list
                 To unsubscribe send an email to
                 discuss-leave@lists.openscad.org

             _______________________________________________
             OpenSCAD mailing list
             To unsubscribe send an email to
             discuss-leave@lists.openscad.org

         _______________________________________________
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         To unsubscribe send an email to
         discuss-leave@lists.openscad.org

     _______________________________________________
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 _______________________________________________
 OpenSCAD mailing list
 To unsubscribe send an email todiscuss-leave@lists.openscad.org

 ---------- Forwarded message ----------
 From: andrew goh via Discuss <discuss@lists.openscad.org>
 To: discuss@lists.openscad.org
 Cc: andrew goh <gohandrew@yahoo.com>
 Bcc:
 Date: Wed, 8 Mar 2023 03:31:47 +0800
 Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds
 _______________________________________________
 OpenSCAD mailing list
 To unsubscribe send an email to discuss-leave@lists.openscad.org

I  use a program called MeshCAM to convert STL files into gCode for my CNC machine.  It is only a 3-axis CNC, so no undercuts, but it does a credible job of creating surfaces from STL files. Jon On 3/7/2023 7:30 PM, Sanjeev Prabhakar wrote: > My idea was not 3d printing the mold, but to machine the mold, that to > from  high density steel material. > > I am also not sure right now whether it is possible to get the > machining codes from an stl file. > > During the process, I have learnt that it is possible to extract the > mould design from the part design in openscad. Though some more work > needs to be done to make it simpler > > On Wed, 8 Mar, 2023, 1:02 am andrew goh via Discuss, > <discuss@lists.openscad.org> wrote: > > > > > ---------- Forwarded message ---------- > From: andrew goh <gohandrew@yahoo.com> > To: discuss@lists.openscad.org > Cc: > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > > I've been thinking about 3d printing molds, say for polyurethane > foam casting. > > I never quite put in the effort to do it. > > I'm a novice in this. > > I'd seem making 3d printed molds may be difficult as it is after > all rather soft materials, and that the expanding foam may expand > so much the mold could deform. > And that it requires a mold release, which i'd guess things that > could be tried could include shoe polish, baby powder, silicone > oil (spray) etc, silicone spray is actually used in metal molds > i'd guess. > > that is actually the lesser of problems, but that i'm not sure how > toxic is the polyurethane materials after all MDI etc if it would > necessitate using a proper VOC respirator etc, quite expensive but > may after all be necessary. expanding foams are quite easy to buy > say from construction products businesses, e.g. for foam > insulation etc. > no need for the speciality types, just that handling the chemicals > I'd guess would need quite some precautions, VOC respirator etc. > > On 05/03/2023 20:37, Sanjeev Prabhakar wrote: >> Wow >> >> Great to hear that >> >> I have almost no experience of sand moulding, but we have made >> hundreds of die casting moulds if not thousands. >> >> In Engineering we have designers who mainly work on expensive >> softwares like nx , Catia, creo, autocad etc. >> >> It's very easy to make mould designs in these softwares, although >> I don't work on that. >> >> Many times I show our designers that openscad could be an >> alternative for some type of designs. >> >> But it seems they don't take me seriously and it's fine. >> >> I like openscad although till date almost no professional work is >> done by me on this, but I intend to make few functions which >> could be useful for professional use. >> >> >> On Sun, 5 Mar, 2023, 2:20 pm nop head, <nop.head@gmail.com> wrote: >> >> My father was a pattern maker, long before 3D printing was a >> thing. He made the patterns out of wood manually and had a >> set of rulers that were out by the contraction ratios of >> different metals, which I still have. >> >> On Sun, 5 Mar 2023 at 08:30, Sanjeev Prabhakar >> <sprabhakar2006@gmail.com> wrote: >> >> That's a good idea, will give it a try in our next project. >> >> >> >> On Sun, 5 Mar, 2023, 12:59 am nop head, >> <nop.head@gmail.com> wrote: >> >> You can print a PLA pattern that is the same as the >> desired final object but expanded by the amount the >> metal contracts and then build a sand or plaster >> mould around it. >> >> PLA can be burned out just as easily as wax. >> >> On Sat, 4 Mar 2023 at 19:24, Steve Schlaifer >> <steve@jetcafe.org> wrote: >> >> You could use this as the start of a lost wax >> process. >> >> Steve Schlaifer >> On Mar 3, 2023 at 4:07 AM -0800, Sanjeev >> Prabhakar <sprabhakar2006@gmail.com>, wrote: >>> Guenther >>> >>> I am not planning to do anything with this. >>> >>> I was just checking if dies can be modelled with >>> this approach. >>> >>> In the process I found it is very complex right >>> now to do something like this. But lot of >>> learning from this challenging work. >>> >>> >>> On Fri, 3 Mar, 2023, 3:38 pm Guenther Sohler, >>> <guenther.sohler@gmail.com> wrote: >>> >>> it looks very nice! >>> Whats your workflow like? >>> apparently you cannot pour molten metal onto >>> the plastic >>> >>> >>> On Thu, Mar 2, 2023 at 6:45 PM Sanjeev >>> Prabhakar <sprabhakar2006@gmail.com> wrote: >>> >>> bottom mould completely done in openscad. >>> >>> <Screenshot 2023-03-02 at 11.10.21 PM.png> >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email todiscuss-leave@lists.openscad.org > > > > ---------- Forwarded message ---------- > From: andrew goh via Discuss <discuss@lists.openscad.org> > To: discuss@lists.openscad.org > Cc: andrew goh <gohandrew@yahoo.com> > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org > > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email todiscuss-leave@lists.openscad.org

 ---------- Forwarded message ----------
 From: andrew goh <gohandrew@yahoo.com <mailto:gohandrew@yahoo.com>>
 To: discuss@lists.openscad.org <mailto:discuss@lists.openscad.org>
 Cc:
 Bcc:
 Date: Wed, 8 Mar 2023 03:31:47 +0800
 Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds

 I've been thinking about 3d printing molds, say for polyurethane
 foam casting.

 I never quite put in the effort to do it.

 I'm a novice in this.

 I'd seem making 3d printed molds may be difficult as it is after
 all rather soft materials, and that the expanding foam may expand
 so much the mold could deform.
 And that it requires a mold release, which i'd guess things that
 could be tried could include shoe polish, baby powder, silicone
 oil (spray) etc, silicone spray is actually used in metal molds
 i'd guess.

 that is actually the lesser of problems, but that i'm not sure how
 toxic is the polyurethane materials after all MDI etc if it would
 necessitate using a proper VOC respirator etc, quite expensive but
 may after all be necessary. expanding foams are quite easy to buy
 say from construction products businesses, e.g. for foam
 insulation etc.
 no need for the speciality types, just that handling the chemicals
 I'd guess would need quite some precautions, VOC respirator etc.

 On 05/03/2023 20:37, Sanjeev Prabhakar wrote:

 Wow

 Great to hear that

 I have almost no experience of sand moulding, but we have made
 hundreds of die casting moulds if not thousands.

 In Engineering we have designers who mainly work on expensive
 softwares like nx , Catia, creo, autocad etc.

 It's very easy to make mould designs in these softwares, although
 I don't work on that.

 Many times I show our designers that openscad could be an
 alternative for some type of designs.

 But it seems they don't take me seriously and it's fine.

 I like openscad although till date almost no professional work is
 done by me on this, but I intend to make few functions which
 could be useful for professional use.


 On Sun, 5 Mar, 2023, 2:20 pm nop head, <nop.head@gmail.com
 <mailto:nop.head@gmail.com>> wrote:

     My father was a pattern maker, long before 3D printing was a
     thing. He made the patterns out of wood manually and had a
     set of rulers that were out by the contraction ratios of
     different metals, which I still have.

     On Sun, 5 Mar 2023 at 08:30, Sanjeev Prabhakar
     <sprabhakar2006@gmail.com <mailto:sprabhakar2006@gmail.com>>
     wrote:

         That's a good idea, will give it a try in our next project.



         On Sun, 5 Mar, 2023, 12:59 am nop head,
         <nop.head@gmail.com <mailto:nop.head@gmail.com>> wrote:

             You can print a PLA pattern that is the same as the
             desired final object but expanded by the amount the
             metal contracts and then build a sand or plaster
             mould around it.

             PLA can be burned out just as easily as wax.

             On Sat, 4 Mar 2023 at 19:24, Steve Schlaifer
             <steve@jetcafe.org <mailto:steve@jetcafe.org>> wrote:

                 You could use this as the start of a lost wax
                 process.

                 Steve Schlaifer
                 On Mar 3, 2023 at 4:07 AM -0800, Sanjeev
                 Prabhakar <sprabhakar2006@gmail.com
                 <mailto:sprabhakar2006@gmail.com>>, wrote:

                 Guenther

                 I am not planning to do anything with this.

                 I was just checking if dies can be modelled with
                 this approach.

                 In the process I found it is very complex right
                 now to do something like this. But lot of
                 learning from this challenging work.


                 On Fri, 3 Mar, 2023, 3:38 pm Guenther Sohler,
                 <guenther.sohler@gmail.com
                 <mailto:guenther.sohler@gmail.com>> wrote:

                     it looks very nice!
                     Whats your workflow like?
                     apparently you cannot pour molten metal onto
                     the plastic


                     On Thu, Mar 2, 2023 at 6:45 PM Sanjeev
                     Prabhakar <sprabhakar2006@gmail.com
                     <mailto:sprabhakar2006@gmail.com>> wrote:

                         bottom mould completely done in openscad.

                         <Screenshot 2023-03-02 at 11.10.21 PM.png>

                         _______________________________________________
                         OpenSCAD mailing list
                         To unsubscribe send an email to
                         discuss-leave@lists.openscad.org
                         <mailto:discuss-leave@lists.openscad.org>

                     _______________________________________________
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                     discuss-leave@lists.openscad.org
                     <mailto:discuss-leave@lists.openscad.org>

                 _______________________________________________
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                 To unsubscribe send an email to
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                 <mailto:discuss-leave@lists.openscad.org>

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                 To unsubscribe send an email to
                 discuss-leave@lists.openscad.org
                 <mailto:discuss-leave@lists.openscad.org>

             _______________________________________________
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             To unsubscribe send an email to
             discuss-leave@lists.openscad.org
             <mailto:discuss-leave@lists.openscad.org>

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         discuss-leave@lists.openscad.org
         <mailto:discuss-leave@lists.openscad.org>

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 _______________________________________________
 OpenSCAD mailing list
 To unsubscribe send an email todiscuss-leave@lists.openscad.org  <mailto:discuss-leave@lists.openscad.org>

 ---------- Forwarded message ----------
 From: andrew goh via Discuss <discuss@lists.openscad.org
 <mailto:discuss@lists.openscad.org>>
 To: discuss@lists.openscad.org <mailto:discuss@lists.openscad.org>
 Cc: andrew goh <gohandrew@yahoo.com <mailto:gohandrew@yahoo.com>>
 Bcc:
 Date: Wed, 8 Mar 2023 03:31:47 +0800
 Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds
 _______________________________________________
 OpenSCAD mailing list
 To unsubscribe send an email to discuss-leave@lists.openscad.org
 <mailto:discuss-leave@lists.openscad.org>

The idea about 3d printing molds is attractive. As if it is feasible, possible it significantly change the costs of low run molding and that new molds can be created by simply printing. The trouble is in the present state of art, this doesn't seem quite feasible yet. Plastic is soft and molding materials is expensive and most importantly worse toxic e.g. polyurethane resin. While the lower cost injection molding is practically not feasible with 3d printed molds except for a few cases, the mold plastics itself will injection molding. Actually, 3d printed molds compares fairly well to silicone molds as that both are soft materials, with a difference that silicone molds are non-stick, at least for some materials e.g. polyurethane etc. And that the art of making silicone molds using silicone pours are fairly well developed, just that silicone is expensive. while a 3d printed ABS, PLA plastic cost much less than a same silicone volume, especially where infill density is reduced. it probably reduce a $100 mold to a $1 mold. On 08/03/2023 08:30, Sanjeev Prabhakar wrote: > My idea was not 3d printing the mold, but to machine the mold, that to > from  high density steel material. > > I am also not sure right now whether it is possible to get the > machining codes from an stl file. > > During the process, I have learnt that it is possible to extract the > mould design from the part design in openscad. Though some more work > needs to be done to make it simpler > > On Wed, 8 Mar, 2023, 1:02 am andrew goh via Discuss, > <discuss@lists.openscad.org <mailto:discuss@lists.openscad.org>> wrote: > > > > > ---------- Forwarded message ---------- > From: andrew goh <gohandrew@yahoo.com <mailto:gohandrew@yahoo.com>> > To: discuss@lists.openscad.org <mailto:discuss@lists.openscad.org> > Cc: > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > > I've been thinking about 3d printing molds, say for polyurethane > foam casting. > > I never quite put in the effort to do it. > > I'm a novice in this. > > I'd seem making 3d printed molds may be difficult as it is after > all rather soft materials, and that the expanding foam may expand > so much the mold could deform. > And that it requires a mold release, which i'd guess things that > could be tried could include shoe polish, baby powder, silicone > oil (spray) etc, silicone spray is actually used in metal molds > i'd guess. > > that is actually the lesser of problems, but that i'm not sure how > toxic is the polyurethane materials after all MDI etc if it would > necessitate using a proper VOC respirator etc, quite expensive but > may after all be necessary. expanding foams are quite easy to buy > say from construction products businesses, e.g. for foam > insulation etc. > no need for the speciality types, just that handling the chemicals > I'd guess would need quite some precautions, VOC respirator etc. > > On 05/03/2023 20:37, Sanjeev Prabhakar wrote: >> Wow >> >> Great to hear that >> >> I have almost no experience of sand moulding, but we have made >> hundreds of die casting moulds if not thousands. >> >> In Engineering we have designers who mainly work on expensive >> softwares like nx , Catia, creo, autocad etc. >> >> It's very easy to make mould designs in these softwares, although >> I don't work on that. >> >> Many times I show our designers that openscad could be an >> alternative for some type of designs. >> >> But it seems they don't take me seriously and it's fine. >> >> I like openscad although till date almost no professional work is >> done by me on this, but I intend to make few functions which >> could be useful for professional use. >> >> >> On Sun, 5 Mar, 2023, 2:20 pm nop head, <nop.head@gmail.com >> <mailto:nop.head@gmail.com>> wrote: >> >> My father was a pattern maker, long before 3D printing was a >> thing. He made the patterns out of wood manually and had a >> set of rulers that were out by the contraction ratios of >> different metals, which I still have. >> >> On Sun, 5 Mar 2023 at 08:30, Sanjeev Prabhakar >> <sprabhakar2006@gmail.com <mailto:sprabhakar2006@gmail.com>> >> wrote: >> >> That's a good idea, will give it a try in our next project. >> >> >> >> On Sun, 5 Mar, 2023, 12:59 am nop head, >> <nop.head@gmail.com <mailto:nop.head@gmail.com>> wrote: >> >> You can print a PLA pattern that is the same as the >> desired final object but expanded by the amount the >> metal contracts and then build a sand or plaster >> mould around it. >> >> PLA can be burned out just as easily as wax. >> >> On Sat, 4 Mar 2023 at 19:24, Steve Schlaifer >> <steve@jetcafe.org <mailto:steve@jetcafe.org>> wrote: >> >> You could use this as the start of a lost wax >> process. >> >> Steve Schlaifer >> On Mar 3, 2023 at 4:07 AM -0800, Sanjeev >> Prabhakar <sprabhakar2006@gmail.com >> <mailto:sprabhakar2006@gmail.com>>, wrote: >>> Guenther >>> >>> I am not planning to do anything with this. >>> >>> I was just checking if dies can be modelled with >>> this approach. >>> >>> In the process I found it is very complex right >>> now to do something like this. But lot of >>> learning from this challenging work. >>> >>> >>> On Fri, 3 Mar, 2023, 3:38 pm Guenther Sohler, >>> <guenther.sohler@gmail.com >>> <mailto:guenther.sohler@gmail.com>> wrote: >>> >>> it looks very nice! >>> Whats your workflow like? >>> apparently you cannot pour molten metal onto >>> the plastic >>> >>> >>> On Thu, Mar 2, 2023 at 6:45 PM Sanjeev >>> Prabhakar <sprabhakar2006@gmail.com >>> <mailto:sprabhakar2006@gmail.com>> wrote: >>> >>> bottom mould completely done in openscad. >>> >>> <Screenshot 2023-03-02 at 11.10.21 PM.png> >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >>> <mailto:discuss-leave@lists.openscad.org> >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >>> <mailto:discuss-leave@lists.openscad.org> >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> To unsubscribe send an email to >>> discuss-leave@lists.openscad.org >>> <mailto:discuss-leave@lists.openscad.org> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> <mailto:discuss-leave@lists.openscad.org> >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> <mailto:discuss-leave@lists.openscad.org> >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> <mailto:discuss-leave@lists.openscad.org> >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to >> discuss-leave@lists.openscad.org >> <mailto:discuss-leave@lists.openscad.org> >> >> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email todiscuss-leave@lists.openscad.org <mailto:discuss-leave@lists.openscad.org> > > > > ---------- Forwarded message ---------- > From: andrew goh via Discuss <discuss@lists.openscad.org > <mailto:discuss@lists.openscad.org>> > To: discuss@lists.openscad.org <mailto:discuss@lists.openscad.org> > Cc: andrew goh <gohandrew@yahoo.com <mailto:gohandrew@yahoo.com>> > Bcc: > Date: Wed, 8 Mar 2023 03:31:47 +0800 > Subject: [OpenSCAD] Re: Surface extraction - 3d printed molds > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org > <mailto:discuss-leave@lists.openscad.org> > > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email todiscuss-leave@lists.openscad.org