The latest thing in metal casting is lost PLA sand casting. Have a model 3D printed in polylacticacid (PLA) plastic as a thin shell without any infill. All the sprues and vents are printed as part of the pattern. The pattern can be rammed up in a single piece mold. No need to remove the pattern, no need to have draft on the pattern and you can do all kinds of funky stuff like undercuts and passages through without needing core inserts to cast around. Oil sand works better than green sand.
Pour in the molten metal and it burns out the PLA. Or the PLA pattern can be coated in plaster or ceramic then burned out and cast using the same methods as lost wax. Check out the cast stack of 7 sprockets http://depts.washington.edu/open3dp/2014/10/rapid-manufacturing-iteration-and-industry/ I bought a small 3D printer, it will soon have itself paid for with just one job making some replacement knobs for a 1940 Graham. I printed them out hollow, with ribs and holes inside to ensure the urethane resin filling will hold. I also designed and printed fixtures to hold rods in position to form pilot drill holes and for the gearshift knob a 3/8-16 bolt. They're in a pressure tank right now while the resin cures. That should have the resin forced into every little nook and cranny. The buyer will be doing the finish work of priming, sanding and painting. Why 3D print? Because the originals were too deteriorated to use for making silicone molds. I also made them some Hudson items and pieces for a 1942 Desoto, including replicating the large, clear plastic hood ornament - but all those were done with regular silicone molds and casting. From: andy pugh <bodge...@gmail.com> To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Sent: Tuesday, August 16, 2016 11:54 AM Subject: Re: [Emc-users] More news & ? from WV. On 16 August 2016 at 18:21, Gene Heskett <ghesk...@shentel.net> wrote: > There's only one problem, the Z screw, if mounted where the old on is, > will be nearly 3.5 inches from the back face, so I'll have to make a big > long pad for the Z nut to interface with it. Have you considered having a casting made? You seem to enjoy woodworking, so pattern making shouldn't be too hard for you. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
