Depending on size, I’d consider some “durabar” or similar continuously cast iron bar. I made a compound for my atlas lathe and several other items from it. A bit hard on tools but the parts have come out great. I prefer to use a face mill to machine the flat surfaces and then carbide tooling to finish it. If you have a three axis CNC mill it might not be much more time and maybe less money than a casting. I usually buy it from speedymetals.com.
I recently did the foundry route for a large (300) batch of aluminum parts and the price was right but it took a long time and required I make up a pattern board with 10 printed patterns per mold. Still haven’t finished machining all 300 … but the castings came out nicely. I used cattail foundry near me in PA. I think it depends on the size and complexity of the part whether it’s worth getting it cast. Matt > On Jan 23, 2022, at 1:59 PM, Chris Albertson <albertson.ch...@gmail.com> > wrote: > > What you give a foundry is typically the part you want, a pattern. They > can advise on the limits of what they can do. For example there is a > minimum and maxim thickness and overall size. > > They can also tell you how much the iron will shrink so you can adjust the > pattern > > Then for you own good you would want to make the pattern so as to minimize > the amount of machine work. This also saves you money as you pay the > foundry by the pound. So make the parrn have all the curves and shape you > need. > > Wrapping is another issue. if you make it too thin or thick the result > will not match the pattern. > > Tranditionally, patterns where made of wood or maybe wood with bondo over > it and sanded and finished sooth. But today you would 3D print the pattern > and give them a plastic copy of the part you want. They pack it in sand > and make a mold from your pattern. > > Some can do a process that is like "lost wax" so then you print using a > kind of plastic that the melted metal burns up > > But this is for a "*mini*-mill" you do NOT need cast iron parts. The > cutting force is very small. Why not make your adaptor out of plastic? > Platic seems like the wrong material because "real mills" are made of > steel. I have a CNC converted Mini mill and the conversion parts are > printed plastic. It you design, knowing the strength of that material > you can do well. I can not measure flex with a dial indcator > Plastic is like designing a part with glass. It is very strong and rigid > until it shatters. But look at the size of the spindle motor and drive > gears on a mini mill. You would shear the teeth off the drive gears > before generating enough force to break a plastic adaptor shim. > > In any case, then after AFTER you know the plastic part works, then you > give the foundry the known-to-work part to use as a pattern and they make > you one in metal. > > I've dealt with some manufacturers and while you used to have to ship a > pattern, now days you can email them the design file and they can print the > pattern and do the design check that looks for violation of thier min and > max thickness. > > There are also places that can do a 3D print in metals like aluminum of > even stainless steel. But this is not yet cheap. > > On Sat, Jan 22, 2022 at 6:26 PM fxkl47BF--- via Emc-users < > emc-users@lists.sourceforge.net> wrote: > >>> Yes, if you are near Windy Hill, then I understand that they do a lot >>> of one-offs for vehicle restorers etc. >>> >>> It's certainly worth considering. >> >> OK >> So from the photos in the ad what would I want to have made? >> A big rectangle? >> The only "true" surfaces on the back are the dovetails. >> I think that's a bit of a wimpy mount. >> If I disassemble it I can tell if the unfinished surfaces beside the >> dovetails are thick enough to drill for additional supports. >> Or is that a lot of overkill. >> Just attach to the dovetails and be done with it. >> I have a 3D printer. >> This is go'n to to be fun :) >> >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users